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THE PRIVATE LINE: (TM) A User's Guide to a MS-DOS Data Encryption Standard Implementation Version 6.0 by Surry P. Everett April 18, 1988 _________________________________________________________________ EVERETT Enterprises, 7855 Wintercress Lane, Springfield, VA 22152 Copyright (c) 1985, 1986, 1987, 1988 by Everett Enterprises. All rights reserved worldwide. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrival system, or translated into any language or computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical, manual or otherwise, without the prior written permission of Everett Enterprises, 7855 Wintercress Lane, Springfield, VA 22152. Non-registered users are granted a limited license to use this product on a trial basis for evaluation purposes, and to copy the program for trial use by others subject to the following limitations: The program is distributed in unmodified form, complete with documentation. No fee, charge or other consideration is required or accepted. The program is not distributed in conjunction with any other product. Single CPU License Registration of The Private Line (TM) licenses you to use the product on one CPU. DISCLAIMER Everett Enterprises makes no representations or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. Further, Everett Enterprises reserves the right to revise this publication and to make changes from time to time in the content hereof without obligation of Everett Enterprises to notify any person of such revision or changes. TRADEMARKS CP/M is a registered trademark of Digital Research. CompuServe is a trademark of CompuServe Inc. EasyLink is a service mark of Western Union Telegraph Company. MS-DOS is a registered trademark of Microsoft Corp. PROCOMM is a trademark of PIL Software Systems. QMODEM is a trademark of the Forbin Project. WORDSTAR is a registered trademark of MicroPro Intl Corp. The Private Line (TM) is a trademark of Everett Enterprises. REGISTRATION ------------ The Private Line is distributed as User-Supported Software. We encourage you to try the program and share it with anyone as long as: The program is distributed complete and unchanged, accompanied by the documentation. No fee, charge or other compensation is requested or received except by Everett Enterprises. The Private Line is not distributed in conjunction with any other product. If you use our program for anything other than evaluation purposes, you are required to register such use. A printed User's Guide will be mailed upon registration. You may register by sending a check or money order for $30.00 to: Everett Enterprises 7855 Wintercress Lane Springfield, VA 22152 Program disks are not included in the registration fee. If you or your company need an invoice in order to generate payment, one is included in this manual. Privacy, like freedom, is not missed until it's not there. The Private Line (TM) is dedicated to Dorothy Everett who shares her friend with a machine or two. We have enclosed invoice and order forms to simplify processing your orders. Use the order form to place an order with us. Use the invoice within your organization to generate payment for The Private Line registrations. We are now providing the program on diskettes for your convenience. Please note that the $10 disk fee covers media costs, postage and handling only. It does not cover registration. If you are using the program for other than evaluation purposes, you are required to register. Business, commercial or governmental use of non-registered copies of The Private Line is strictly forbidden. Write for details of site or corporate licensing. Invoice Form Remit to: Everett Enterprises 7855 Wintercress Lane Springfield, VA 22152 (703) 866-3914 Sold to: Ship to: -------------------- -------------------- -------------------- -------------------- -------------------- -------------------- ============================================================ Date: PO #: ============================================================ Quan Description Unit Extended ------------------------------------------------------------ | | | | The Private Line Registration | $30.00 | $ -----| | | | The Private Line Evaluation Disk | $10.00 | $ -----| | | | The Private Line User's Guide, | $ 6.00 | $ -----| printed version | | ------------------------------------------------------------ Total: $ Orders outside the U.S.: Add $15, send check drawn on U.S. bank in U.S. dollars, or international money order in U.S. dollars. Order Form Make check Everett Enterprises payable to: 7855 Wintercress Lane Springfield, VA 22152 ============================================================ Date: PO #: ============================================================ Quan Description Unit Extended ------------------------------------------------------------ | | | | The Private Line Registration | $30.00 | $ -----| (Includes printed User's Guide, | | | but does not include disk) | | | | | | The Private Line Evaluation Disk | $10.00 | $ -----| (current version, manual on | | | disk) | | | | | | The Private Line User's Guide, | $ 6.00 | $ -----| printed version | | ------------------------------------------------------------ Total: $ Payment by: ( ) Check ( ) Money Order Name: ------------------------------------------------ Addr: ------------------------------------------------ : ------------------------------------------------ Orders outside the U.S.: Add $15, send check drawn on U.S. bank in U.S. dollars, or international money order in U.S. dollars. Orders may also be placed using CompuServe: 70320,107 Information Request Mail to: Everett Enterprises 7855 Wintercress Lane Springfield, VA 22152 Please send information regarding corporate and site licenses. Name: ------------------------------------------------- Title: ------------------------------------------------- Company: ------------------------------------------------- Addr: ------------------------------------------------- : ------------------------------------------------- City: ------------------------------------------------- State: ------------------------------------------------- Zip: ------------------------------------------------- Day Phone: ------------------------------------------------- Estimated copies needed: ----------------------------------- Possible uses: --------------------------------------------- --------------------------------------------- --------------------------------------------- --------------------------------------------- Questions: ------------------------------------------------- ------------------------------------------------- ------------------------------------------------- ------------------------------------------------- ------------------------------------------------- Table of Contents Section Page I. Introduction 1 A. What is it? 1 B. Who needs it? 1 II. Operating The Private Line (TM) 2 A. Receiving The Private Line (TM) 2 1. Making a back-up copy 2 2. Floppy disk system 2 3. Hard disk system 3 B. Using The Private Line (TM) 3 1. Single file encryption 3 2. Single file decryption 9 3. Displaying files 9 4. Purging files 10 5. Displaying disk directories 13 6. Double file decryption/encryption 14 7. Converting files to ASCII format 15 8. Converting files to binary format 16 9. Printing files 17 10. Disk write verify toggle switch 17 11. Key entry echo toggle switch 19 12. Creating a sub-directory 19 13. Changing the current sub-directory 20 14. Removing a sub-directory 21 15. Erasing a file from a sub-directory 22 16. Verification of compliance with the Data Encryption Standard 23 17. Selecting Alphabetic or Hexidecimal keys 28 18. Changing Purging Status 29 19. Saving Switch Settings 30 20. Selecting Command Line exit action 31 21. Changing File Re-use Status 32 22. DES Modes of Operation 33 Electronic Codebook 33 Cipher Block Chaining 34 Cipher Feedback 35 Output Feedback 36 Table of Contents (continued) Section Page 23. Short Block Processing 36 24. Initialization Values 38 C. Command Line execution 38 1. Encryption 38 2. Decryption 39 3. Convert file to ASCII form 39 4. Convert file to Binary form 39 5. Command line exit action 40 D. Other Aspects of the Private Line (TM) 40 1. Selection of keys 40 2. Protection of keys 40 3. Destruction of unencrypted data 40 III. Requirements 41 IV. References 42 V. Problem Report 43 VI. Changes and Updates 44 VII. Index 46 I. Introduction A. What is The Private Line? The Private Line (TM) is a software implementation of the Data Encryption Algorithm using the Data Encryption Standard (DES) published by the National Bureau of Standards, U.S. Department of Commerce (NBS). The Private Line (TM) will decrypt files and messages encrypted by either hardware or other software implementations of the DES which meet NBS specifications. Files of either text or object code may be easily encrypted or decrypted. The Private Line (TM) provides a secure means of transmitting and storing messages and MS-DOS files without the danger of having an uninvited person read them. It provides a remedy to that age-old fear of having some one, be it a too nosy neighbor on a party line, hackers breaking a computer bulletin board's safeguards, or your 'friendly' big brother, reading your private material. In order for a file which has been encrypted by The Private Line (TM) to be transmitted to another user, a communications package, such as XMODEM by Ward Christensen (which is in the public domain), KERMIT, PROCOMM or QMODEM and a modem may be needed. The Private Line (TM) works without them but it will not allow one to up or download files from CompuServe or the Source. By using the expansion option of The Private Line, one may send encrypted messages on EasyLink, telegraph networks and other standard telecommunications networks and bulletin boards such as CompuServe and the Source in ASCII form. B. Who needs The Private Line? Anyone who transmits MS-DOS files of messages, data, or executable programs that are subject to be read, viewed, copied or otherwise accessed by people other than the intended recipient. Users who communicate by bulletin board or other electronic systems such as Telex or EasyLink may wish to use The Private Line. Writers who submit articles over networks such as CompuServe or the Source should consider using The Private Line. Anyone who has sensitive data laying around on a diskette should encrypt it in order to prevent unauthorized access. People who develop software in teams and communicate by leaving messages on networks should use The Private Line. People such as doctors and lawyers who keep personal financial or other sensitive records on diskettes, or on line, either on hard disks, bulletin boards, or otherwise, should use The Private Line. In short anyone should use The Private Line who has something that the user does not want to share, be it a message, a program, or just personal data. II. Operating The Private Line A. Receiving The Private Line. 1. Making a back-up copy. It will arrive on a diskette readable by your computer system. Before using The Private Line you should, for your own protection, make a back-up work copy of the distribution diskette and store the original in a safe place. Remember that the User's License allows you to make as many copies as you need for backup purposes only (if you registered your use of The Private Line) or to give away for evaluation purposes. Use a file copy program, such as MS-DOS's COPY, to make the copy and verify that it is accurately copied. A MS-DOS command such as COPY A: B: will copy all files on The Private Line original diskette. Remember that The Private Line does not have a copy of the MS-DOS operating system on it and that the backup diskette must be formatted before it can be used to store a copy of The Private Line. If you need additional help, refer to your MS-DOS system documentation on FORMAT and COPY or refer to one of the MS-DOS references listed in Section V of this manual. In short, take the following steps to make a back-up copy: a. Format a blank diskette and copy MS-DOS to it using FORMAT. b. Put the new diskette containing MS-DOS on Drive A: and put The Private Line original diskette on Drive B:. c. Execute the command COPY B:*.* A:. All files on The Private line will be copied to your backup copy. The following files are on The Private Line diskette: (1) PRIVATE.EXE - The heart of The Private Line. This is the executable program which one uses. (2) MSG.DAT - additional information and a sample message in clear text and (3) MSG.ENC - sample message in encrypted form. (4) Read.me - any last minute information from Everett Enterprises. d. Execute the command COMP A: B:. All files on The Private line original diskette will be compared to your backup copy. e. Put The Private Line original diskette in a secure, safe place. 2. Floppy disk system. Begin using The Private Line by inserting the diskette containing the work copy of The Private Line into a disk drive and by typing 'X:PRIVATE' after the MS-DOS prompt and pressing RETURN. 'X' is the letter designator of the disk drive in which you inserted the diskette. The Private Line will begin execution just like any other executable MS-DOS file. The Private Line will provide easy, clear and user-friendly instructions as it is used. 3. Hard disk system. a. Create a subdirectory called 'C:\tpl' using the MS-DOS command, MKDIR. b. Insert the working copy of The Private Line into drive A and type: copy a:*.* C:\tpl. Press RETURN and all files contained on the diskette will be copied to the correct sub-directory. c. Edit or create the autoexec.bat file contained on the root directory on the boot drive so that it will include a path command which requires the operating system to check the sub-directory, 'C:\tpl'. The path line in the autoexec.bat file will look similar to: 'path C:\tpl'. If there are multiple entries in the path command, each entry is separated with a semi-colon. d. After editing the autoexec.bat file, reboot the system by pressing the CNTL, ALT, and DEL keys at the same time. e. Begin using The Private Line by typing 'PRIVATE' after the MS-DOS prompt and pressing RETURN. The Private Line will begin execution just like any other executable MS-DOS file. The Private Line will provide easy, clear and user-friendly instructions as it is used. B. Using The Private Line. 1. Single file encryption: a. Insert the diskette containing the work copy of The Private Line into a disk drive. If the disk drive is not the currently logged disk drive, type the letter designator (A-P) of the disk drive being used, followed by a colon. Press RETURN. b. Type 'PRIVATE' after the MS-DOS prompt and press RETURN. (Note: some keyboards use ENTER or CARRIAGE RETURN, rather than RETURN). The Private Line will begin execution by displaying a copyright notice which will quickly be replaced by the master menu for The Private Line (see Figure 1). c. Press the letter 'A' (either upper or lower case) to encrypt a file. ____________________________________________________________________________ THE PRIVATE LINE MASTER MENU A. Single File Encryption G. Convert File to ASCII B. Single File Decryption H. Convert File to Binary C. Return to MS-DOS I. Double File Encryption D. Display File in Hex Format J. Double File Decryption E. Purge File from Disk K. Print Disk File F. Display Disk Directory L. Additional Options Enter the letter of your choice: ____________________________________________________________________________ Current Switch Selections DES Mode: ERlectronic Codebook Short Block: No Padding Key type: Alphabetic Disk verify after write: On Automatic Purging (after encryption): No Purge Prompt (after encryption): Yes (after decryption): NO (after decryption): Yes Times purged file overwritten: 1 Command Line: Exit Re-use existing files: Prompt Key Entry Echo: On ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Ln, Springfield, VA 22152 ____________________________________________________________________________ Figure 1. d. The Private Line will ask for the name of the file to be encrypted (see Figure 2). Enter the file name in the MS-DOS format, filename.filetype, if the file to be encrypted is on the currently logged disk drive and in the current directory. The currently logged disk drive is the drive which appears with the MS-DOS prompt symbol, such as A> or B>. Otherwise, use the form X:\pathname\filename.filetype where 'X' is a disk drive (A-P) that exists on your system; \pathname is a valid pathname; filename is a 1-8 character filename; filetype is a 3 character file type, such as ASM, BAS, COM, DAT, HEX, PAS, or PRN. Either lower or upper case characters may be used, but all characters are changed to upper case. If the file to be encrypted is not on the same disk as The Private Line, insert that diskette into another disk drive before entering the name of the file. If the disk drive does not exist or the file can not be found, The Private Line will tell you to press the RETURN key and will then ask you to enter the file name. If at any time you wish to cancel the current operation and to return to either the master menu or the additional options menu, simply press the CONTROL key and the letter 'R' at the same time (CNTL-R) whenever The Private Line is waiting for input from the terminal. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE ENCRYPTED? (DISK:FILENAME.FILETYPE) _______________________________________________________________ Figure 2. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE ENCRYPTED? (DISK:\PATHNAME\FILENAME.FILETYPE) FILE NOT FOUND (PRESS RETURN TO RE-ENTER) _______________________________________________________________ Figure 3. e. After entering the file name, The Private Line will open a file to contain the encrypted data. The file will be placed on the chosen disk. The file name of the encrypted file will be the same as that of the file to be encrypted. The file type, however, will be 'ENC'. For example, if the file to be encrypted is 'A:SECRET.DAT', then the file to hold the encrypted data will be X:SECRET.ENC' where 'X' is the disk drive you selected. If the user did not enter a disk drive, the currently logged disk drive is used. If the file can not be found, a message (see Figure 3) is displayed, and the user is instructed to press the RETURN key. (1) The Private Line will attempt to open the new file if there is room on the chosen disk. If there is not enough room to open the file or if there is another error, a message will be displayed. Press RETURN to return to the master menu. (2) The Private Line will also check to see if the file to contain the encrypted data already exists on the selected disk. If it does and the user has not changed the settings of the file re-use switch (default=prompt), the user will be asked if it should be overwritten (see Figure 4). The user should press either 'Y' for yes or 'N' for no. If yes, The Private Line continues. If no, The Private Line asks if the user wants to return to the master menu or if the user wants to enter a new file name to contain the encrypted data (see Figure 5). The user should press either 'A' or 'B'. If 'A' is pressed, The Private Line returns to the master menu. If _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE ENCRYPTED? (DISK:\PATHNAME\FILENAME.FILETYPE) ENTER THE LETTER DESIGNATOR (A-P) OF THE DISK ON WHICH THE ENCRYPTED FILE IS TO BE PLACED: FILE ALREADY EXISTS. DO YOU WANT TO OVERWRITE IT (Y/N)? _______________________________________________________________ Figure 4. 'B' is selected, the user is asked for the name of the file to contain the encrypted data (see Figure 6). Any valid MS-DOS \pathname\filename.filetype on any valid disk drive may be used. If the file re-use switch has been set to re-use, the file will automatically be overwritten. f. After the file to be encrypted and the file to hold the encrypted data have been selected and opened, The Private Line will ask for the key to be used (see Figure 7). The key will be echoed to the terminal as it is entered. If the user desires to disable the key entry echo feature, see para 11, 'Key Entry Echo Toggle Switch.' _______________________________________________________________ THE PRIVATE LINE OPTIONS A - RETURN TO THE MASTER MENU. B - ENTER A NEW NAME FOR THE NEW FILE. ENTER THE LETTER OF YOUR CHOICE: _______________________________________________________________ Figure 5. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE CREATED? (DISK:\PATHNAME\FILENAME.FILETYPE) _______________________________________________________________ Figure 6. _______________________________________________________________ THE PRIVATE LINE Enter the alphabetic key to be used (1-8 characters): (FOR EXAMPLE: aBcdeFGh) _______________________________________________________________ Figure 7. (1) The user should enter 1-8 characters in the format in Figure 7 and press RETURN. After entering 8 charcters, the user will be allowed only to enter a character editing key such as left-arrow or back-space or to press RETURN. If less than 8 characters are entered when RETURN is pressed, the key is right-filled with blanks (hex value 20H). Please note that key characters are case specific, i.e., there is a difference between an uppper and lower case letter. (2) After pressing RETURN, The Private Line will display the key which you entered (see Figure 8) and ask if it is correct. Press a 'Y' or 'N' for yes or no. If 'Y' is pressed, The Private Line continues. If 'N' is pressed, The Private Line again asks for the key to be used. Remember, CNTL-R will return the user to the master menu. If the key entry echo feature has been turned off, the verification step will be bypassed. _______________________________________________________________ THE PRIVATE LINE LISTED BELOW IS THE KEY YOU ENTERED: aBcdeFGh IS IT CORRECT (Y/N)? _______________________________________________________________ Figure 8. g. After the key has been verified, The Private Line begins to read the input file, encode it and write the encrypted file to the output disk. As a reminder the names of the encrypted file and the file being encrypted are displayed. A counter is displayed and incremented as each 256 bytes of data is processed. h. After the file has been encrypted, the user may be asked if the plain text source file should be purged (overwritten with binary zeros and then removed from the directory). If the answer is no, the user is returned to the master menu. If the answer is 'yes', then after confirmation, the file is purged before the user is returned to the master menu (see Figures 9 and 10). When the file has been purged, the user will be notified and told to press RETURN to continue (see Figure 11). The user will then be returned to the master menu. The default setting for the automatic purge after encryption is NO. The default setting for the purge prompt is YES. If the automatic purge switch has been set to automatic, the source file will automatically be purged, regardless of the purge prompt switch setting. _______________________________________________________________ THE PRIVATE LINE ENCRYPTING: X:FILENAME.FILETYPE ENCRYPTED FILE IS: X:FILENAME.ENC USING: Electronic Codebook DO YOU WANT TO PURGE THE ABOVE PLAIN TEXT SOURCE FILE (Y/N)? _______________________________________________________________ Figure 9. _______________________________________________________________ THE PRIVATE LINE ENCRYPTING: X:FILENAME.FILETYPE ENCRYPTED FILE IS: X:FILENAME.ENC USING: Electronic Codebook DO YO WANT TO PURGE THE ABOVE PLAIN TEXT SOURCE FILE (Y/N)? PHYSICALLY ERASING: X:FILENAME.FILETYPE _______________________________________________________________ Figure 10. _______________________________________________________________ THE PRIVATE LINE ENCRYPTING: X:FILENAME.FILETYPE ENCRYPTED FILE IS: X:FILENAME.ENC USING: Electronic Codebook CONFIRM PURGE OF X:FILENAME.FILETYPE (Y/N)? PHYSICALLY ERASING: X:FILENAME.FILETYPE FILE OVERWRITTEN WITH BINARY ZEROS AND THEN DELETED PRESS RETURN TO CONTINUE _______________________________________________________________ Figure 11. 2. Decrypting files: Files may be decrypted using the same procedures as in encryption. However, press 'B' for decryption when the master menu is displayed, and then continue exactly as for encryption in accordance with the instructions contained in paragraph B1c thru B1h. Remember, the same key which was used in the encryption process must be used for decryption. 3. Displaying files: Normally there is no need to display files which have been encrypted or are to be encrypted. Displaying COM files certainly does not reveal anything, but it can be done by using utilities such as DUMP and Cntl-P. Text files which are in the clear may be displayed using utilities such as TYPE or text editors such as WORDSTAR. However, for the few times that one may want to review a file, The Private Line provides the capability. It should be understood that an encrypted text file is not a text file. a. From the master menu of The Private Line, press 'D'. The Private Line will ask for the name of the file to be displayed (see Figure 12). It must be contained in the current or specified directory. The existence of the file will be checked. If an error is found, the user will be prompted (see Figure 13) for corrective action. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE DISPLAYED? (DISK:\PATHNAME\FILENAME.FILETYPE) _______________________________________________________________ Figure 12. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE DISPLAYED? (DISK:\PATHNAME\FILENAME.FILETYPE) FILE NOT FOUND (PRESS RETURN TO RE-ENTER) _______________________________________________________________ Figure 13. b. The Private Line will read the desired file and display a CRT screen of data and then pause. The user will be prompted to choose between viewing the next screen of data (see Figure 14) by pressing RETURN or returning to the master menu by pressing CNTL-R. Each byte will be printed in hex format (two hex digits). In addition, all displayable bytes (hex value 20H thru 7EH) will be displayed. Nondisplayable bytes are represented by a period. c. After the end of the file has been reached, the user will be informed and asked to press the RETURN key (see Figure 15). This allows the user to view the last screeen of data in the file. 4. Purging files: After a file has been encrypted or decrypted, it may be necessary, for security purposes, to purge the original file. When MS-DOS erases a file, only the name is removed from the disk directory, the data remains on the disk (see para 15, 'Erasing Files'). With patience and a little effort, some one could reconstruct the file thought to be erased. Therefore, a means is provided in which the file to be erased is overwritten with binary zeros before it is purged from the MS-DOS disk directory. It also should be noted that because of the manner in which backup files are created by text editors such as WORDSTAR and EDLIN, care should be exercised to avoid leaving backup files (file type: BAK) available for general access. Please note that the _______________________________________________________________ THE PRIVATE LINE 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ................ 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F !"#$%&'()*+,-./ 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 0123456789:;<=>? 40 41 42 44 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F @ABCDEFGHIJKLMNO 50 51 52 55 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F PQRSTUVWXYZ[ ]^- 60 61 62 66 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 'abcdefghijklmno 70 71 72 77 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F pqrstuvwxyz{|}~. 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F !"#$%&'()*+,-./ 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 0123456789:;<=>? 40 41 42 44 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F @ABCDEFGHIJKLMNO 50 51 52 55 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F PQRSTUVWXYZ[ ]^- 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F !"#$%&'()*+,-./ 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 0123456789:;<=>? PRESS RETURN FOR NEXT SCREEN, CNTL-R FOR MASTER MENU _______________________________________________________________ Figure 14. _______________________________________________________________ THE PRIVATE LINE 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ................ 01 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F ................ 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F !"#$%&'()*+,-./ 50 51 52 55 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F PQRSTUVWXYZ[ ]^- END OF FILE REACHED. PRESS RETURN TO CONTINUE. _______________________________________________________________ Figure 15. default settings of the automatic purge and purge prompt switches are 'no' and 'prompt' respectively. This means that unless the user changes the default settings, the user will be prompted after a file is encrypted. In order to completely purge a file, follow these steps: a. From The Private Line master menu, press the letter 'E' (either upper or lower case) to purge a file. b. The Private Line will ask for the name of the file to be purged (see Figure 16). The file to be purged must be in the current or specified directory. If the file can not be found, The Private Line will tell you to press the RETURN key and will then ask you to enter the file name (see Figure 25). If at any time you wish to return to the master menu, simply press the CONTROL key and the letter 'R' (CNTL-R) at the same time whenever The Private Line is waiting for input from the terminal. The master menu will then re-appear. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE PURGED? (DISK:\PATHNAME\FILENAME.FILETYPE) _______________________________________________________________ Figure 16. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE PURGED? (DISK:\PATHNAME\FILENAME.FILETYPE) FILE NOT FOUND (PRESS RETURN TO RE-ENTER) _______________________________________________________________ Figure 17. c. If the file is found, the user will be asked to verify that the file is to be purged by pressing 'Y' or 'N' (see Figure 18). If 'Y' is pressed, purging begins and the data will be destroyed (see Figure 19). If 'N' is pressed, the user will be returned to the master menu. After the file has been purged, the user will be informed that the file has been overwritten with binary zeros and deleted. The user is then instructed to press RETURN to continue (see Figure 20). After pressing RETURN, the user is returned to the master menu. The file will be overwritten 1-9 times before the file name is removed from the directory. The default number is 1; it may be changed from the Additional Options Menu. _______________________________________________________________ THE PRIVATE LINE Confirm PURGE of x:\pathname\filename.filetype (y/n)? _______________________________________________________________ Figure 18. _______________________________________________________________ THE PRIVATE LINE Confirm PURGE of x:\pathname\filename.filetype (y/n)? PHYSICALLY ERASING X:\PATHNAME\FILENAME.FILETYPE _______________________________________________________________ Figure 19. _______________________________________________________________ THE PRIVATE LINE Confirm PURGE of x:\pathname\filename.filetype (y/n)? PHYSICALLY ERASING X:\PATHNAME\FILENAME.FILETYPE FILE OVERWRITTEN WITH BINARY ZEROS AND DELETED PRESS RETURN TO CONTINUE _______________________________________________________________ Figure 20. 5. Displaying disk directories: a. From The Private Line master menu, press the letter 'F' (either upper or lower case) to list a disk directory. b. The Private Line will ask for the pathname of the directory which is to be displayed (see Figure 21). Type any valid disk drive,pathname and use any valid wildcard characters. You may simply press RETURN for the default directory (*.*). c. The Private Line will then display the pathname which you entered. The filenames contained in that directory will be printed in alphabetical order in one to four columns. Directory entries will be marked with an asterisk. If there are more than fifty-six entries a message will be shown which will instruct the user to press RETURN for more listings. When there are no more listings, a message indicating the end of the listings will be shown and the user will be instructed to press RETURN to return to the master menu (see Figure 22). _______________________________________________________________ THE PRIVATE LINE Enter the pathname of the desired directory: (disk:\pathname\filename.filetype, RETURN = *.*) _______________________________________________________________ Figure 21. _______________________________________________________________ THE PRIVATE LINE Directory of - A:\ROOT\SUB1 PROG1 ASM : PROG1 HEX : PROG1 PRN : SUB11 * : TEST DAT : TEST HEX : * DIRECTORY ENTRIES END OF DIRECTORY LISTINGS. PRESS RETURN TO RETURN TO MASTER MENU. _______________________________________________________________ Figure 22. 6. Double file decryption and encryption: a. Single file encryption generally is secure enough for most users. However, some people feel that it is too vulnerable and suggest double encryption. Double encryption involves encrypting an encrypted file, preferrably with a different key. Even the most doubtful critic of the Data Encryption Standard admits that a file doubly encrypted with two different keys, will be secure from brute force solution for at least five to ten years! b. Options 'I' and 'J' on the master menu will automatically double encrypt or decrypt a file. When either option is selected, the user will be prompted to enter a second key after providing the first key if hexidecimal keys are used. If alphabetic keys are used, only one key consisting of 1-16 characters is entered. The default key type is alphabetic. Of course double encryption takes more time than single encryption, but it is less than twice as much. Remember, for decryption the same keys must be entered in the same order as for the encryption process. Thus, the 1st key for encryption also is the 1st key for decryption. Note: if single decryption is used twice to decrypt a double encrypted file, then the key entered second in the encryption process must be used first in the decryption process. Other than being prompted to enter a second key, double encryption and decryption proceed as in para 1, 'Encrypting files.' Remember that alphabetic keys of length 9 to 15 characters are right-filled with blanks (hex value 20H). 7. Converting files to ASCII format: a. An encrypted file contains binary data, i.e., values from 00H thru 0FFH or 0 thru 255 decimal. Thus, a communications program such as XMODEM normally is required to transfer an encrypted file. However, for the people who desire to send encrypted files over Western Union, E-Mail, or similar services, ASCII files are required. ASCII files do not contain control characters. Option 'G' will expand any file into an ASCII file with a normal file type of EXP. It will be about 37% larger than the original file. Carriage returns and line feeds are inserted after each 64 characters in the expanded file. b. The file to be expanded must be in the current or specified directory of the selected disk. c. Press the letter 'G' (either upper or lower case) to expand a file. d. The Private Line will ask for the name of the file to be expanded (see Figure 23). _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE EXPANDED? (DISK:\PATHNAME\FILENAME.FILETYPE) _______________________________________________________________ Figure 23. e. After entering the file name, The Private Line will open a file to contain the expanded data. The file will be placed on the chosen disk using its current or specified directory. The file name of the expanded file will be the same as that of the file to be expanded. The file type, however, will be 'EXP'. For example, if the file to be expanded is 'A:SECRET.DAT', then the file to hold the expanded data will be X:SECRET.EXP' where 'X' is the disk drive you selected. If the user did not enter a disk drive, the currently logged disk drive is used. (1) The Private Line will attempt to open the new file if there is room on the chosen disk. If there is not enough room to open the file or if there is another error, a message will be displayed. Press RETURN to return to the master menu. (2) The Private Line will also check to see if the file to contain the expanded data already exists on the selected diskette. If it does, the user will be asked if it should be overwritten (see Figure 24). The user should press either 'Y' for yes or 'N' for no. If yes, The Private Line continues. If no, The Private Line asks if the user wants to return to the master menu or if the user wants to enter a new file name to contain the expanded data (see Figure 5). The user should press either 'A' or 'B'. If 'A' is pressed, The Private Line returns to the master menu. If 'B' is selected, the user is asked for the name of the file to contain the expanded data. The file will be placed on the selected disk using its current or specified directory. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE EXPANDED? (DISK:\PATHNAME\FILENAME.FILETYPE) FILE ALREADY EXISTS. DO YOU WANT TO OVERWRITE IT (Y/N)? _______________________________________________________________ Figure 24. f. After the file to be expanded and the file to hold the expanded data have been selected and opened, The Private Line will read the input file, expanded it, and write it to the expandsion file. As a reminder, the names of the expanded file and the file being expanded are displayed. The user will be returned to the master menu upon completion of the expansion. 8. Converting files to binary format: a. Option 'H' will contract any file into a binary file with a normal file type of CON. Carriage returns and line feeds inserted by Option 'G' are discarded. It will not make sense to use Option 'H' on any file other than a file of type EXP. The same checks are made for overwriting existing files as in the expansion option. b. Files may be contracted using the same procedures as in the expansion process. However, press 'H" for converting a file into binary format when the master menu is displayed, and then continue as for expansion in accordance with the instructions in para 7, 'Converting files to ASCII format.' 9. Printing Files. a. Option 'K' will print a selected file on the MS-DOS PRN device. Remember, only ASCII files can be printed. Thus, encrypted files can not be printed. However, you could encrypt a file, use Option 'G' to convert it to an ASCII file, and then print the new file using Option 'K'. If a file with a file type of EXE, COM, CON, or ENC is selected for printing, a warning message will be displayed and the user will be allowed to continue or to return to the master menu. During print, an 'S' will stop/start the printing process. A CNTL-R will return the user to the master menu. b. The file to be printed must be in the current or specified directory prior to option 'K' being selected. 10. Disk Write Verify switch: a. If the disk write verify toggle switch is on, a verify is performed during write operations to the disk drive to insure that data was written correctly. Although more time is required with the verify switch on, a higher degree of confidence in the data written is obtained. The additional time required is very small. Therefore, it is recommended that the verify switch be left on. The default condition is ON. b. To change the disk write verify toggle switch, select 'L', ADDITIONAL OPTIONS, on the master menu. The additional options menu (see Figure 25), will appear. Press 'A' and the verify toggle switch will be displayed (see Figure 26). c. Press 'A' to turn the switch on. The switch will be turned on and the display updated to reflect the new condition. Press 'C' to return to the additional options menu. ____________________________________________________________________________ THE PRIVATE LINE ADDITIONAL OPTIONS MENU A. Disk Write Verify Toggle Switch I. Change Purging Status B. Key Entry Echo Toggle Switch J. Save Switch Settings to Disk C. Create Sub-Directory K. Command LineExit Status D. Change Current Sub-Directory L. Change FileRe-use Status E. Remove Sub-Directory M. Set DES Mode of Operation F. Erase File N. Return to Master Menu G. Return to Master Menu O. Change Initialization Value H. Select Alphabetic / Hex Keys P. Return to Master Menu ____________________________________________________________________________ Current Switch Selections DES Mode: Electronic Codebook Short Block: No Padding Key type: Alphabetic Disk verify after write: On Automatic Purging (after encryption): No Purge Prompt (after encryption): Yes (after decryption): NO (after decryption): Yes Times purged file overwritten: 1 Command Line: Exit Re-use existing files: Prompt Key Entry Echo: On ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Ln, Springfield, VA 22152 ____________________________________________________________________________ Figure 25. _______________________________________________________________ THE PRIVATE LINE DISK WRITE VERIFY TOGGLE SWITCH CURRENT STATUS: ON A. TURN VERIFY SWITCH ON B. TURN VERIFY SWITCH OFF C. RETURN TO OPTIONS MENU _______________________________________________________________ Figure 26. d. Press 'B' to turn the switch off. The switch will be turned off and the display updated to reflect the new condition. Press 'C' to return to the additional options menu. 11. Key Entry Echo toggle switch: a. If the key entry toggle switch is on, the key is displayed as it is entered during the encryption and decryption process. If the switch is turned off, the cursor will move as each character is entered, but only the commas will be shown and the verify step will be skipped. The default condition is ON. b. To change the key entry echo toggle switch, select 'L', ADDITIONAL OPTIONS, on the master menu. The additional options menu (see Figure 41), will appear. Press 'B' and the key entry toggle switch will be displayed (see Figure 27). c. Press 'A' to turn the switch on. The switch will be turned on and the display updated to reflect the new condition. Press 'C' to return to the additional options menu. _______________________________________________________________ THE PRIVATE LINE KEY ENTRY ECHO TOGGLE SWITCH CURRENT STATUS: ON A. TURN VERIFY SWITCH ON B. TURN VERIFY SWITCH OFF C. RETURN TO OPTIONS MENU _______________________________________________________________ Figure 27. 12. Creating a sub-directory: a. Creating a sub-directory is the same as the MKDIR function in MS-DOS. b. To create a sub-directory, choose option 'L' on the master menu in order to obtain the additional options menu. c. Press 'C' when the additional options menu appears. The user will be asked to enter the disk drive on which the new sub-directory is to be created (see Figure 28). d. Press any letter (A-P) lower or upper case, which represents a disk drive on your system. Again The Private Line will check to determine if the entered disk drive actually exists. It it does not exist, a message will be displayed. It it exists, but is not the default drive, a message will be displayed which instructs the user to insert the desired diskette and to press RETURN. e. The current directory pathname of the selected disk drive will be displayed and the user will be prompted to enter the name of the sub-directory to be created (see Figure 29). You have to enter the backslash followed by the name of the sub-directory to be created. Press RETURN. _______________________________________________________________ THE PRIVATE LINE ENTER THE LETTER DESIGNATOR (A-P) OF THE DISK DRIVE ON WHICH THE SUB-DIRECTORY SHOULD BE CREATED? _______________________________________________________________ Figure 28. _______________________________________________________________ THE PRIVATE LINE CURRENT DIRECTORY: X: WHAT IS THE PATHNAME OF THE SUB-DIRECTORY TO BE CREATED? _______________________________________________________________ Figure 29. f. The sub-directory will be created and the user returned to the additional options menu. If an error occurs, a message will be displayed and the user will be instructed to press RETURN to return to the additional options menu. 13. Changing the current sub-directory: a. Changing the current sub-directory is the same as the CHDIR function in MS-DOS. b. To change the current sub-directory, choose option 'L' on the master menu in order to obtain the additional options menu. c. Press 'D' when the additional options menu appears. The user will be asked to enter the disk drive on which the current sub-directory is to be changed (see Figure 30). d. Press any letter (A-P) lower or upper case, which represents a disk drive on your system. e. The current directory pathname of the selected disk drive will be displayed and the user will be prompted to enter the name of the new current sub-directory (see Figure 31). You have to enter the backslash followed by the name of the sub-directory to be changed. Press RETURN. f. The current sub-directory will be changed and the user returned to the additional options menu. If an error occurs, a message will be displayed and the user will be instructed to press RETURN to return to the additional options menu. _______________________________________________________________ THE PRIVATE LINE ENTER THE LETTER DESIGNATOR (A-P) OF THE DISK DRIVE OF WHICH THE SUB-DIRECTORY SHOULD BE CHANGED? _______________________________________________________________ Figure 30. _______________________________________________________________ THE PRIVATE LINE CURRENT DIRECTORY: X: WHAT IS THE PATHNAME OF THE NEW SUB-DIRECTORY? _______________________________________________________________ Figure 31. 14. Removing a sub-directory: a. Removing a sub-directory is the same as the RMDIR function in MS-DOS. b. To remove a sub-directory, choose option 'L' on the master menu in order to obtain the additional options menu. c. Press 'E' when the additional options menu appears. The user will be asked to enter the disk drive on which the sub-directory is to be removed (see Figure 32). d. Press any letter (A-P) lower or upper case, which represents a disk drive on your system. e. The current directory pathname of the selected disk drive will be displayed and the user will be prompted to enter the name of the sub-directory to be removed (see Figure 33). You have to enter the backslash followed by the name of the sub-directory to be removed. Press RETURN. f. The sub-directory will be removed and the user returned to the additional options menu. If an error occurs, a message will be displayed and the user will be instructed to press RETURN to return to the additional options menu. _______________________________________________________________ THE PRIVATE LINE ENTER THE LETTER DESIGNATOR (A-P) OF THE DISK DRIVE OF WHICH THE SUB-DIRECTORY SHOULD BE REMOVED? _______________________________________________________________ Figure 32. _______________________________________________________________ THE PRIVATE LINE CURRENT DIRECTORY: X: WHAT IS THE PATHNAME OF THE SUB-DIRECTORY TO BE REMOVED? _______________________________________________________________ Figure 33. 15. Erasing a file from a sub-directory: a. Erasing a file from a sub-directory is the same as using the 'del' command in MS-DOS. b. From The Private Line master menu, choose option 'L' in order to obtain the additional options menu. c. When the additional options menu appears, press 'F' (either upper or lower case) to erase a file from the directory. d. The Private Line will ask for the name of the file to be erased (see Figure 34). The file to be erased must be in the current or specified directory of the selected drive. _______________________________________________________________ THE PRIVATE LINE WHAT IS THE NAME OF THE FILE TO BE ERASED? _______________________________________________________________ Figure 34. The Private Line will then attempt to find the desired file. If the file is found, the user will be asked to verify that the file is to be erased by pressing 'Y' or 'N' (see Figure 35). If 'Y' is pressed, the filename will be removed from the directory. If 'N' is pressed, the user will be returned to the additional options menu. After the filename has been erased, the user will be informed that the filename has been removed from the directory. The user is then instructed to press RETURN to continue. After pressing RETURN, the user is returned to the additional options menu. _______________________________________________________________ THE PRIVATE LINE Confirm Erasure of x:\pathname\filename.filetype (y/n)? _______________________________________________________________ Figure 35. 16. Verification of Compliance with Data Encryption Standard. Another feature is provided for those who desire more proof that The Private Line actually works in compliance with the requirements of the Data Encryption Standard contained in NBS Special Publication 500-20. Listed below are the hexidecimal values of the test keys, plain text, and ciphers used by the National Bureau of Standards in order to determine if an encryption algorithm produces the correct output. You may check these by selecting Option G, Test DES Compliance, on the Additional Options Menu. As each of the 171 tests are performed, The Private Line will display the test key, test plain text, expected cipher code and the generated cipher. The expected cipher will be compared to the cipher generated by The Private Line and the results of the comparison will be displayed for each test. These tests are also performed each time that The Private Line is started, as part of the initialization process, however, no indication is given unless one of the tests fail. If one of the tests fail, the only thing a user can do is to copy the source diskette of The Private Line in order to obtain a good copy. If that does not work, something has damaged or destroyed the data contained on the diskette. You will need to obtain another copy by downloading it or by requesting another disk from Everett Enterprises at a nominal handling/postage charge of $10. KEY PLAIN TEXT CIPHER TEXT IP and E tests 1. 01,01,01,01,01,01,01,01 95,F8,A5,E5,DD,31,D9,00 80,00,00,00,00,00,00,00 2. 01,01,01,01,01,01,01,01 DD,7F,12,1C,A5,01,56,19 40,00,00,00,00,00,00,00 3. 01,01,01,01,01,01,01,01 2E,86,53,10,4F,38,34,EA 20,00,00,00,00,00,00,00 4. 01,01,01,01,01,01,01,01 4B,D3,88,FF,6C,D8,1D,4F 10,00,00,00,00,00,00,00 5. 01,01,01,01,01,01,01,01 20,B9,E7,67,B2,FB,14,56 08,00,00,00,00,00,00,00 6. 01,01,01,01,01,01,01,01 55,57,93,80,D7,71,38,EF 04,00,00,00,00,00,00,00 7. 01,01,01,01,01,01,01,01 6C,C5,DE,FA,AF,04,51,2F 02,00,00,00,00,00,00,00 8. 01,01,01,01,01,01,01,01 0D,9F,27,9B,A5,D8,72,60 01,00,00,00,00,00,00,00 9. 01,01,01,01,01,01,01,01 D9,03,1B,02,71,BD,5A,0A 00,80,00,00,00,00,00,00 10. 01,01,01,01,01,01,01,01 42,42,50,B3,7C,3D,D9,51 00,40,00,00,00,00,00,00 11. 01,01,01,01,01,01,01,01 B8,06,1B,7E,CD,9A,21,E5 00,20,00,00,00,00,00,00 12. 01,01,01,01,01,01,01,01 F1,5D,0F,28,6B,65,BD,28 00,10,00,00,00,00,00,00 13. 01,01,01,01,01,01,01,01 AD,D0,CC,8D,6E,5D,EB,A1 00,08,00,00,00,00,00,00 14. 01,01,01,01,01,01,01,01 E6,D5,F8,27,52,AD,63,D1 00,04,00,00,00,00,00,00 15. 01,01,01,01,01,01,01,01 EC,BF,E3,BD,3F,59,1A,5E 00,02,00,00,00,00,00,00 16. 01,01,01,01,01,01,01,01 F3,56,83,43,79,D1,65,CD 00,01,00,00,00,00,00,00 17. 01,01,01,01,01,01,01,01 2B,9F,98,2F,20,03,7F,A9 00,00,80,00,00,00,00,00 18. 01,01,01,01,01,01,01,01 88,9D,E0,68,A1,6F,0B,E6 00,00,40,00,00,00,00,00 19. 01,01,01,01,01,01,01,01 E1,9E,27,5D,84,6A,12,98 00,00,20,00,00,00,00,00 20. 01,01,01,01,01,01,01,01 32,9A,8E,D5,23,D7,1A,EC 00,00,10,00,00,00,00,00 21. 01,01,01,01,01,01,01,01 E7,FC,E2,25,57,D2,3C,97 00,00,08,00,00,00,00,00 22. 01,01,01,01,01,01,01,01 12,A9,F5,81,7F,F2,D6,5D 00,00,04,00,00,00,00,00 23. 01,01,01,01,01,01,01,01 A4,84,C3,AD,38,DC,9C,19 00,00,02,00,00,00,00,00 24. 01,01,01,01,01,01,01,01 FB,E0,0A,8A,1E,F8,AD,72 00,00,01,00,00,00,00,00 25. 01,01,01,01,01,01,01,01 75,0D,07,94,07,52,13,63 00,00,00,80,00,00,00,00 26. 01,01,01,01,01,01,01,01 64,FE,ED,9C,72,4C,2F,AF 00,00,00,40,00,00,00,00 27. 01,01,01,01,01,01,01,01 F0,2B,26,3B,32,8E,2B,60 00,00,00,20,00,00,00,00 28. 01,01,01,01,01,01,01,01 9D,64,55,5A,9A,10,B8,52 00,00,00,10,00,00,00,00 29. 01,01,01,01,01,01,01,01 D1,06,FF,0B,ED,52,55,D7 00,00,00,08,00,00,00,00 30. 01,01,01,01,01,01,01,01 E1,65,2C,6B,13,8C,64,A5 00,00,00,04,00,00,00,00 31. 01,01,01,01,01,01,01,01 E4,28,58,11,86,EC,8F,46 00,00,00,02,00,00,00,00 32. 01,01,01,01,01,01,01,01 AE,B5,F5,ED,E2,2D,1A,36 00,00,00,01,00,00,00,00 33. 01,01,01,01,01,01,01,01 E9,43,D7,56,8A,EC,0C,5C 00,00,00,00,80,00,00,00 34. 01,01,01,01,01,01,01,01 DF,98,C8,27,6F,54,B0,4B 00,00,00,00,40,00,00,00 35. 01,01,01,01,01,01,01,01 B1,60,E4,68,0F,6C,69,6F 00,00,00,00,20,00,00,00 36. 01,01,01,01,01,01,01,01 FA,07,52,B0,7D,9C,4A,B8 00,00,00,00,10,00,00,00 KEY PLAIN TEXT CIPHER TEXT IP and E tests (continued) 37. 01,01,01,01,01,01,01,01 CA,3A,2B,03,6D,BC,85,02 00,00,00,00,08,00,00,00 38. 01,01,01,01,01,01,01,01 5E,09,05,51,7B,B5,9B,CF 00,00,00,00,04,00,00,00 39. 01,01,01,01,01,01,01,01 81,4E,EB,3B,91,D9,07,26 00,00,00,00,02,00,00,00 40. 01,01,01,01,01,01,01,01 4D,49,DB,15,32,91,9C,9F 00,00,00,00,01,00,00,00 41. 01,01,01,01,01,01,01,01 25,EB,5F,C3,F8,CF,06,21 00,00,00,00,00,80,00,00 42. 01,01,01,01,01,01,01,01 AB,6A,20,C0,62,0D,1C,6F 00,00,00,00,00,40,00,00 43. 01,01,01,01,01,01,01,01 79,E9,0D,BC,98,F9,2C,CA 00,00,00,00,00,20,00,00 44. 01,01,01,01,01,01,01,01 86,6E,CE,DD,80,72,BB,0E 00,00,00,00,00,10,00,00 45. 01,01,01,01,01,01,01,01 8B,54,53,6F,2F,3E,64,A8 00,00,00,00,00,08,00,00 46. 01,01,01,01,01,01,01,01 EA,51,D3,97,55,95,B8,6B 00,00,00,00,00,04,00,00 47. 01,01,01,01,01,01,01,01 CA,FF,C6,AC,45,42,DE,31 00,00,00,00,00,02,00,00 48. 01,01,01,01,01,01,01,01 8D,D4,5A,2D,DF,90,79,6C 00,00,00,00,00,01,00,00 49. 01,01,01,01,01,01,01,01 10,29,D5,5E,88,0E,C2,D0 00,00,00,00,00,00,80,00 50. 01,01,01,01,01,01,01,01 5D,86,CB,23,63,9D,BE,A9 00,00,00,00,00,00,40,00 51. 01,01,01,01,01,01,01,01 1D,1C,A8,53,AE,7C,0C,5F 00,00,00,00,00,00,20,00 52. 01,01,01,01,01,01,01,01 CE,33,23,29,24,8F,32,28 00,00,00,00,00,00,10,00 53. 01,01,01,01,01,01,01,01 84,05,D1,AB,E2,4F,B9,42 00,00,00,00,00,00,08,00 54. 01,01,01,01,01,01,01,01 E6,43,D7,80,90,CA,42,07 00,00,00,00,00,00,04,00 55. 01,01,01,01,01,01,01,01 48,22,1B,99,37,74,8A,23 00,00,00,00,00,00,02,00 56. 01,01,01,01,01,01,01,01 DD,7C,0B,BD,61,FA,FD,54 00,00,00,00,00,00,01,00 57. 01,01,01,01,01,01,01,01 2F,BC,29,1A,57,0D,B5,C4 00,00,00,00,00,00,00,80 58. 01,01,01,01,01,01,01,01 E0,7C,30,D7,E4,E2,6E,12 00,00,00,00,00,00,00,40 59. 01,01,01,01,01,01,01,01 09,53,E2,25,8E,8E,90,A1 00,00,00,00,00,00,00,20 60. 01,01,01,01,01,01,01,01 5B,71,1B,C4,CE,EB,F2,EE 00,00,00,00,00,00,00,10 61. 01,01,01,01,01,01,01,01 CC,08,3F,1E,6D,9E,85,F6 00,00,00,00,00,00,00,08 62. 01,01,01,01,01,01,01,01 D2,FD,88,67,D5,0D,2D,FE 00,00,00,00,00,00,00,04 63. 01,01,01,01,01,01,01,01 06,E7,EA,22,CE,92,70,8F 00,00,00,00,00,00,00,02 64. 01,01,01,01,01,01,01,01 16,6B,40,B4,4A,BA,4B,D6 00,00,00,00,00,00,00,01 KEY PLAIN TEXT CIPHER TEXT PC1 AND PC2 TESTS 65. 80,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 95,A8,D7,28,13,DA,A9,4D 66. 40,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 0E,EC,14,87,DD,8C,26,D5 67. 20,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 7A,D1,6F,FB,79,C4,59,26 68. 10,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 D3,74,62,94,CA,6A,6C,F3 69. 08,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 80,9F,5F,87,3C,1F,D7,61 70. 04,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 C0,2F,AF,FE,C9,89,D1,FC 71. 02,01,01,01,01,01,01,01 00,00,00,00,00,00,00,00 46,15,AA,1D,33,E7,2F,10 72. 01,80,01,01,01,01,01,01 00,00,00,00,00,00,00,00 20,55,12,33,50,C0,08,58 73. 01,40,01,01,01,01,01,01 00,00,00,00,00,00,00,00 DF,3B,99,D6,57,73,97,C8 74. 01,20,01,01,01,01,01,01 00,00,00,00,00,00,00,00 31,FE,17,36,9B,52,88,C9 KEY PLAIN TEXT CIPHER TEXT PC1 AND PC2 TESTS (continued) 75. 01,10,01,01,01,01,01,01 00,00,00,00,00,00,00,00 DF,DD,3C,C6,4D,AE,16,42 76. 01,08,01,01,01,01,01,01 00,00,00,00,00,00,00,00 17,8C,83,CE,2B,39,9D,94 77. 01,04,01,01,01,01,01,01 00,00,00,00,00,00,00,00 50,F6,36,32,4A,9B,7F,80 78. 01,02,01,01,01,01,01,01 00,00,00,00,00,00,00,00 A8,46,8E,E3,BC,18,F0,6D 79. 01,01,80,01,01,01,01,01 00,00,00,00,00,00,00,00 A2,DC,9E,92,FD,3C,DE,92 80. 01,01,40,01,01,01,01,01 00,00,00,00,00,00,00,00 CA,C0,9F,79,7D,03,12,87 81. 01,01,20,01,01,01,01,01 00,00,00,00,00,00,00,00 90,BA,68,0B,22,AE,B5,25 82. 01,01,10,01,01,01,01,01 00,00,00,00,00,00,00,00 CE,7A,24,F3,50,E2,80,B6 83. 01,01,08,01,01,01,01,01 00,00,00,00,00,00,00,00 88,2B,FF,0A,A0,1A,0B,87 84. 01,01,04,01,01,01,01,01 00,00,00,00,00,00,00,00 25,61,02,88,92,45,11,C2 85. 01,01,02,01,01,01,01,01 00,00,00,00,00,00,00,00 C7,15,16,C2,9C,75,D1,70 86. 01,01,01,80,01,01,01,01 00,00,00,00,00,00,00,00 51,99,C2,9A,52,C9,F0,59 87. 01,01,01,40,01,01,01,01 00,00,00,00,00,00,00,00 C2,2F,0A,29,4A,71,F2,9F 88. 01,01,01,20,01,01,01,01 00,00,00,00,00,00,00,00 EE,37,14,83,71,4C,02,EA 89. 01,01,01,10,01,01,01,01 00,00,00,00,00,00,00,00 A8,1F,BD,44,8F,9E,52,2F 90. 01,01,01,08,01,01,01,01 00,00,00,00,00,00,00,00 4F,64,4C,92,E1,92,DF,ED 91. 01,01,01,04,01,01,01,01 00,00,00,00,00,00,00,00 1A,FA,9A,66,A6,DF,92,AE 92. 01,01,01,02,01,01,01,01 00,00,00,00,00,00,00,00 B3,C1,CC,71,5C,B8,79,D8 93. 01,01,01,01,80,01,01,01 00,00,00,00,00,00,00,00 19,D0,32,E6,4A,B0,BD,8B 94. 01,01,01,01,40,01,01,01 00,00,00,00,00,00,00,00 3C,FA,A7,A7,DC,87,20,DC 95. 01,01,01,01,20,01,01,01 00,00,00,00,00,00,00,00 B7,26,5F,7F,44,7A,C6,F3 96. 01,01,01,01,10,01,01,01 00,00,00,00,00,00,00,00 9D,B7,3B,3C,0D,16,3F,54 97. 01,01,01,01,08,01,01,01 00,00,00,00,00,00,00,00 81,81,B6,5B,AB,F4,A9,75 98. 01,01,01,01,04,01,01,01 00,00,00,00,00,00,00,00 93,C9,B6,40,42,EA,A2,40 99. 01,01,01,01,02,01,01,01 00,00,00,00,00,00,00,00 55,70,53,08,29,70,55,92 100. 01,01,01,01,01,80,01,01 00,00,00,00,00,00,00,00 86,38,80,9E,87,87,87,A0 101. 01,01,01,01,01,40,01,01 00,00,00,00,00,00,00,00 41,B9,A7,9A,F7,9A,C2,08 102. 01,01,01,01,01,20,01,01 00,00,00,00,00,00,00,00 7A,9B,E4,2F,20,09,A8,92 103. 01,01,01,01,01,10,01,01 00,00,00,00,00,00,00,00 29,03,8D,56,BA,6D,27,45 104. 01,01,01,01,01,08,01,01 00,00,00,00,00,00,00,00 54,95,C6,AB,F1,E5,DF,51 105. 01,01,01,01,01,04,01,01 00,00,00,00,00,00,00,00 AE,13,DB,D5,61,48,89,33 106. 01,01,01,01,01,02,01,01 00,00,00,00,00,00,00,00 02,4D,1F,FA,89,04,E3,89 107. 01,01,01,01,01,01,80,01 00,00,00,00,00,00,00,00 D1,39,97,12,F9,9B,F0,2E 108. 01,01,01,01,01,01,40,01 00,00,00,00,00,00,00,00 14,C1,D7,C1,CF,FE,C7,9E 109. 01,01,01,01,01,01,20,01 00,00,00,00,00,00,00,00 1D,E5,27,9D,AE,3B,ED,6F 110. 01,01,01,01,01,01,10,01 00,00,00,00,00,00,00,00 E9,41,A3,3F,85,50,13,03 111. 01,01,01,01,01,01,08,01 00,00,00,00,00,00,00,00 DA,99,DB,BC,9A,03,F3,79 112. 01,01,01,01,01,01,04,01 00,00,00,00,00,00,00,00 B7,FC,92,F9,1D,8E,92,E9 113. 01,01,01,01,01,01,02,01 00,00,00,00,00,00,00,00 AE,8E,5C,AA,3C,A0,4E,85 114. 01,01,01,01,01,01,01,80 00,00,00,00,00,00,00,00 9C,C6,2D,F4,3B,6E,ED,74 115. 01,01,01,01,01,01,01,40 00,00,00,00,00,00,00,00 D8,63,DB,B5,C5,9A,91,A0 116. 01,01,01,01,01,01,01,20 00,00,00,00,00,00,00,00 A1,AB,21,90,54,5B,91,D7 117. 01,01,01,01,01,01,01,10 00,00,00,00,00,00,00,00 08,75,04,1E,64,C5,70,F7 118. 01,01,01,01,01,01,01,08 00,00,00,00,00,00,00,00 5A,59,45,28,BE,BE,F1,CC KEY PLAIN TEXT CIPHER TEXT PC1 AND PC2 TESTS (continued) 119. 01,01,01,01,01,01,01,04 00,00,00,00,00,00,00,00 FC,DB,32,91,DE,21,F0,C0 120. 01,01,01,01,01,01,01,02 00,00,00,00,00,00,00,00 86,9E,FD,7F,9F,26,5A,09 KEY PLAIN TEXT CIPHER TEXT PTESTS 121. 10,46,91,34,89,98,01,31 00,00,00,00,00,00,00,00 88,D5,5E,54,F5,4C,97,B4 122. 10,07,10,34,89,98,80,20 00,00,00,00,00,00,00,00 0C,0C,C0,0C,83,EA,48,FD 123. 10,07,10,34,C8,98,01,20 00,00,00,00,00,00,00,00 83,BC,8E,F3,A6,57,01,83 124. 10,46,10,34,89,98,80,20 00,00,00,00,00,00,00,00 DF,72,5D,CA,D9,4E,A2,E9 125. 10,86,91,15,19,19,01,01 00,00,00,00,00,00,00,00 E6,52,B5,3B,55,0B,E8,B0 126. 10,86,91,15,19,58,01,01 00,00,00,00,00,00,00,00 AF,52,71,20,C4,85,CB,B0 127. 51,07,B0,15,19,58,01,01 00,00,00,00,00,00,00,00 0F,04,CE,39,3D,B9,26,D5 128. 10,07,B0,15,19,19,01,01 00,00,00,00,00,00,00,00 C9,F0,0F,FC,74,07,90,67 129. 31,07,91,54,98,08,01,01 00,00,00,00,00,00,00,00 7C,FD,82,A5,93,25,2B,4E 130. 31,07,91,94,98,08,01,01 00,00,00,00,00,00,00,00 CB,49,A2,F9,E9,13,63,E3 131. 10,07,91,15,B9,08,01,40 00,00,00,00,00,00,00,00 00,B5,88,BE,70,D2,3F,56 132. 31,07,91,15,98,08,01,40 00,00,00,00,00,00,00,00 40,6A,9A,6A,B4,33,99,AE 133. 10,07,D0,15,89,98,01,01 00,00,00,00,00,00,00,00 6C,B7,73,61,1D,CA,9A,DA 134. 91,07,91,15,89,98,01,01 00,00,00,00,00,00,00,00 67,FD,21,C1,7D,BB,5D,70 135. 91,07,D0,15,89,19,01,01 00,00,00,00,00,00,00,00 95,92,CB,41,10,43,07,87 136. 10,07,D0,15,98,98,01,20 00,00,00,00,00,00,00,00 A6,B7,FF,68,A3,18,DD,D3 137. 10,07,94,04,98,19,01,01 00,00,00,00,00,00,00,00 4D,10,21,96,C9,14,CA,16 138. 01,07,91,04,91,19,04,01 00,00,00,00,00,00,00,00 2D,FA,9F,45,73,59,49,65 139. 01,07,91,04,91,19,01,01 00,00,00,00,00,00,00,00 B4,66,04,81,6C,0E,07,74 140. 01,07,94,04,91,19,04,01 00,00,00,00,00,00,00,00 6E,7E,62,21,A4,F3,4E,87 141. 19,07,92,10,98,1A,01,01 00,00,00,00,00,00,00,00 AA,85,E7,46,43,23,31,99 142. 10,07,91,19,98,19,08,01 00,00,00,00,00,00,00,00 2E,59,19,DB,4D,19,62,D6 143. 10,07,91,19,98,1A,08,01 00,00,00,00,00,00,00,00 23,A8,66,A8,09,D3,08,94 144. 10,07,92,10,98,19,01,01 00,00,00,00,00,00,00,00 D8,12,D9,61,F0,17,D3,20 145. 10,07,91,15,98,19,01,0B 00,00,00,00,00,00,00,00 05,56,05,81,6E,58,60,8F 146. 10,04,80,15,98,19,01,01 00,00,00,00,00,00,00,00 AB,D8,8E,8B,1B,77,16,F1 147. 10,04,80,15,98,19,01,02 00,00,00,00,00,00,00,00 53,7A,C9,5B,E6,9D,A1,E1 148. 10,04,80,15,98,19,01,08 00,00,00,00,00,00,00,00 AE,D0,F6,AE,3C,25,CD,D8 149. 10,02,91,15,98,10,01,04 00,00,00,00,00,00,00,00 B3,E3,5A,5E,E5,3E,7B,8D 150. 10,02,91,15,98,19,01,04 00,00,00,00,00,00,00,00 61,C7,9C,71,92,1A,2E,F8 151. 10,02,91,15,98,10,02,01 00,00,00,00,00,00,00,00 E2,F5,72,8F,09,95,01,3C 152. 10,02,91,16,98,10,01,01 00,00,00,00,00,00,00,00 1A,EA,C3,9A,61,F0,A4,64 KEY PLAIN TEXT CIPHER TEXT S-BOX TESTS 153. 7C,A1,10,45,4A,1A,6E,57 01,A1,D6,D0,39,77,67,42 69,0F,5B,0D,9A,26,93,9B 154. 01,31,D9,61,9D,C1,37,6E 5C,D5,4C,A8,3D,EF,57,DA 7A,38,9D,10,35,4B,D2,71 155. 07,A1,13,3E,4A,0B,26,86 02,48,D4,38,06,F6,71,72 86,8E,BB,51,CA,B4,59,9A 156. 38,49,67,4C,26,02,31,9E 51,45,4B,58,2D,DF,44,0A 71,78,87,6E,01,F1,9B,2A 157. 04,B9,15,BA,43,FE,B5,B6 42,FD,44,30,59,57,7F,A2 AF,37,FB,42,1F,8C,40,95 158. 01,13,B9,70,FD,34,F2,CE 05,9B,5E,08,51,CF,14,3A 86,A5,60,F1,0E,C6,D8,5B 159. 01,70,F1,75,46,8F,B5,E6 07,56,D8,E0,77,47,61,D2 0C,D3,DA,02,00,21,DC,09 160. 43,29,7F,AD,38,E3,73,FE 76,25,14,B8,29,BF,48,6A EA,67,6B,2C,B7,DB,2B,7A 161. 07,A7,13,70,45,DA,2A,16 3B,DD,11,90,49,37,28,02 DF,D6,4A,81,5C,AF,1A,0F 162. 04,68,91,04,C2,FD,3B,2F 26,95,5F,68,35,AF,60,9A 5C,51,3C,9C,48,86,C0,88 163. 37,D0,6B,B5,16,CB,75,46 16,4D,5E,40,4F,27,52,32 0A,2A,EE,AE,3F,F4,AB,77 164. 1F,08,26,0D,1A,C2,46,5E 6B,05,6E,18,75,9F,5C,CA EF,1B,F0,3E,5D,FA,57,5A 165. 58,40,23,64,1A,BA,61,76 00,4B,D6,EF,09,17,60,62 88,BF,0D,B6,D7,0D,EE,56 166. 02,58,16,16,46,29,B0,07 48,0D,39,00,6E,E7,62,F2 A1,F9,91,55,41,02,0B,56 167. 49,79,3E,BC,79,B3,25,8F 43,75,40,C8,69,8F,3C,FA 6F,BF,1C,AF,CF,FD,05,56 168. 4F,B0,5E,15,15,AB,73,A7 07,2D,43,A0,77,07,52,92 2F,22,E4,9B,AB,7C,A1,AC 169. 49,E9,5D,6D,4C,A2,29,BF 02,FE,55,77,81,17,F1,2A 5A,6B,61,2C,C2,6C,CE,4A 170. 01,83,10,DC,40,9B,26,D6 1D,9D,5C,50,18,F7,28,C2 5F,4C,03,8E,D1,2B,2E,41 171. 1C,58,7F,1C,13,92,4F,EF 30,55,32,28,6D,6F,29,5A 63,FA,C0,D0,34,D9,F7,93 17. Selecting Alphabetic or Hexidecimal keys a. Either hexidecimal or alphabetic keys may be selected by choosing Option H on the Additional Options Menu. b. From the Master Menu, select Option L, Additional Options Menu by pressing the letter 'L', upper or lower case. c. From the Additional Options Menu, select Option H by pressing the letter 'H', upper or lower case. When the Key Type Status Menu appears (see Figure 36), press the letter of your choice. The menu will be changed to reflect your selection. Press the letter 'C' to return to the Additional Options Menu. d. Your selection will be effective for the duration of this work session only. If you wish to change it again during this session, repeat the steps a thru c, above. e. If you wish to make your selection the new default which will be in effect the next time The Private Line is started, see Section 19, Saving Switch Settings. f. Only alphabetic keys may be used in the command line mode. It does not matter what the current default setting is. If you have chosen hexidecimal keys and saved that selection, you still are required to use alphabetic keys from the command line. However, if you also have selected the command line exit action of Master Menu, then you will enter a key according to the current setting once you return to the Master Menu. _______________________________________________________________ THE PRIVATE LINE KEY TYPE STATUS CURRENT STATUS: Alphabetic OPTIONS A. Use Hexidecimal keys B. Use Alphabetic keys C. RETURN TO OPTIONS MENU Enter the letter of your choice: _______________________________________________________________ Figure 36. 18. Changing Purging Status a. Several features may be selected concerning the purging status. b. From the Master Menu, select Option L, Additional Options Menu by pressing the letter 'L', upper or lower case. c. From the Additional Options Menu, select Option I by pressing the letter 'I', upper or lower case. When the Purging Status Menu appears (see Figure 37), press the letter of your choice. The menu will be changed to reflect your selection. Press the letter 'C' to return to the Additional Options Menu. d. Your selection will be effective for the duration of this work session only. If you wish to change it again during this session, repeat the steps a thru c, above. e. If you wish to make your selection the new default which will be in effect the next time The Private Line is started, see Section 19, Saving Switch Settings. f. It should be noted that if you select automatic purge of the input file after encryption, you will not be prompted to confirm the purge, regardless of the setting of the prompt switch. This is also true for automatic purging after decryption. ____________________________________________________________________________ THE PRIVATE LINE PURGING STATUS OPTIONS A. Change Automatic purge status after encryption B. Change Automatic purge status after decryption C. Change purge prompt status after encryption D. Changepurge prompt status after decryption E. Enter the number of times purged file is overwritten F. Return to Additional Options Menu Enter the letter of your choice: ____________________________________________________________________________ Current Switch Selections DES Mode: Electronic Codebook Short Block: No Padding Key type: Alphabetic Disk verify after write: On Automatic Purging (after encryption): No Purge Prompt (after encryption): Yes (after decryption): NO (after decryption): Yes Times purged file overwritten: 1 Command Line: Exit Re-use existing files: Prompt Key Entry Echo: On ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Ln, Springfield, VA 22152 ____________________________________________________________________________ Figure 37. 19. Saving Switch Settings a. The switch settings displayed below the Master Menu may be changed from the Additional Options Menu for either the duration of the current session by selecting the appropriate option or they may be changed permamently, also from the Additional Options Menu using Option J. b. To change an individual option for the duration of the current work session, see the appropriate section. c. To save the current settings permamently, select Option L, Additional Options Menu from the Master Menu by pressing the letter 'L', upper or lower case. d. From the Additional Options Menu, select Option J by pressing the letter 'J', upper or lower case. When the Save Switch Settings to Disk Menu appears (see Figure 38), press the letter of your choice. The switch settings will be saved in \tpl.def and you will be returned to the Additional Options Menu. e. The current settings will be effective until you change them during this work session. If you change your selection during this session but do not save it to disk, you will obtain the previous default settings when you again use The Private Line. f. If you delete \tpl.def from the root directory, you will obtain the original default settings shown below: ____________________________________________________________________________ THE PRIVATE LINE Save Switch Settings to Disk OPTIONS A. Save Current Switch Settings to Disk B. RETURN TO OPTIONS MENU Enter the letter of your choice: ____________________________________________________________________________ Current Switch Selections DES Mode: Electronic Codebook Short Block: No Padding Key type: Alphabetic Disk verify after write: On Automatic Purging (after encryption): No Purge Prompt (after encryption): Yes (after decryption): NO (after decryption): Yes Times purged file overwritten: 1 Command Line: Exit Re-use existing files: Prompt Key Entry Echo: On ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Ln, Springfield, VA 22152 ____________________________________________________________________________ Figure 38. 20. Selecting Command Line exit action a. You may either exit to the operating system or you may exit to the master menu upon termination of the command line action. Command line exit action is selected by choosing Option K on the Additional Options Menu. b. From the Master Menu, select Option L, Additional Options Menu by pressing the letter 'L', upper or lower case. c. From the Additional Options Menu, select Option K by pressing the letter 'K', upper or lower case. When the Command Line Exit Status Menu appears (see Figure 39), press the letter of your choice. The menu will be changed to reflect your selection. Press the letter 'C' to return to the Additional Options Menu. d. Your selection will be effective for the duration of this work session only. If you wish to change it again during this session, repeat the steps a thru c, above. e. If you wish to make your selection the new default which will be in effect the next time The Private Line is started, see Section 19, Saving Switch Settings. _________________________________________________________________ THE PRIVATE LINE Command Line Exit Status CURRENT STATUS: Menu OPTIONS A. Exit after Command Line B. Return to Master Menu after Command Line C. RETURN TO OPTIONS MENU Enter the letter of your choice: _________________________________________________________________ Figure 39. 21. Changing File Re-use Status a. You may automatically re-use a file which currently exits or you may be prompted before it is re-used. b. From the Master Menu, select Option L, Additional Options Menu by pressing the letter 'L', upper or lower case. c. From the Additional Options Menu, select Option L by pressing the letter 'L', upper or lower case. When the Change File Re-use Status Menu appears (see Figure 40), press the letter of your choice. The menu will be changed to reflect your selection. Press the letter 'C' to return to the Additional Options Menu. d. Your selection will be effective for the duration of this work session only. If you wish to change it again during this session, repeat the steps a thru c, above. e. If you wish to make your selection the new default which will be in effect the next time The Private Line is started, see Section 19, Saving Switch Settings. _________________________________________________________________ THE PRIVATE LINE Re-Use Existing File Status CURRENT STATUS: Prompt OPTIONS A. Prompt user before re-use B. Automatically re-use C. RETURN TO OPTIONS MENU Enter the letter of your choice: _________________________________________________________________ Figure 40. 22. DES Modes of Operation. a. Electronic Codebook Mode (ECB). The electronic codebook mode is defined as follows: 1. In ECB encryption, a plain text data block is used directly as the DES input block which is processed through a DES device in the encrypt state. The resulting output block is used as the cipher text. If the plain text does not consist of an integral number of data blocks, then the final partial data block is processed using either padding or cipher text stealing, depending on the user selection for Short Blocks. 2. In ECB decryption, a cipher text data block is used directly as the DES input block which is processed through a DES device in the decrypt state. The resulting output block is the plain text. If the plain text does not consist of an integral number of data blocks, then the final partial data block is processed using either padding or cipher text stealing, depending on the user selection for Short Blocks. 3. To use ECB mode, take the following steps: (a) From the additional options menu, select Option 'M'. See Figure 41. (b) Select the DES Mode of choice by pressing the letter which represents the desired mode. ____________________________________________________________________________ THE PRIVATE LINE DES Mode of Operation CURRENT STATUS: Electronic Codebook OPTIONS A. Electronic Codebook B. Cipher Block Chaining C. 64 Bit Cipher Feedback D. 64 Bit Output Feedback E. 8 Bit Cipher Feedback F. 8 Bit Output Feedback G. Return to Options Menu Enter the letter of your choice: ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Lane, Springfield, VA 22152 ____________________________________________________________________________ Figure 41. (c) Once you make a selection, the current status will be changed and the DES Mode of Operation Menu will re-appear. Press 'G' to return to the Additional Options Menu. b. Cipher Block Chaining Mode (CBC). The cipher block chaining mode is defined as follows: (1) In CBC encryption, a plain text is divided into blocks. The first DES input block is formed by exclusive-ORing the first block of a message with a 64-bit initialization value (IV). The input block is processed through a DES device in the encrypt state and the resulting output block is used as the first cipher text. The cipher text block is then exclusive-ORed with the next plain text data block to form the next DES input block, which is processed through the DES device in the encrypt state to produce the the next cipher text block. This encryption process continues to "chain" successive cipher and plain text blocks until the last plain text block in the message is encrypted. If the plain text does not consist of an integral number of data blocks, then the final partial data block is processed using either padding or cipher text stealing, depending on the user selection for Short Blocks. (2) In CBC decryption, the first cipher text block is used as the input block and is processed through a DES device in the decrypt state; the resulting output block is then exclusive-ORed with the initialization value (must be the same as that used during encryption) to produce the first plain text block. The second cipher text block is then used as the input block and is processed through the DES device in the decrypt state and the resulting output block is exclusive-ORed witht the first cipher text block to produce the second plain text block. The CBC decryption process continues in this manner until the last complete cipher text block has been decrypted. If the cipher text does not consist of an integral number of data blocks, then the final partial data block is processed using either padding or cipher text stealing, depending on the user selection for Short Blocks. (3) To use CBC mode, take the following steps: (a) From the additional options menu, select Option 'M'. See Figure 41. (b) Select the DES Mode of choice by pressing the letter which represents the desired mode. After the current status has been updated, select another choice or return to the Additional Options menu. c. Cipher Feedback Mode (CFB). The cipher feedback mode is defined as follows: (1) A message to be encrypted is divided into data units each containing K bits. In both the CFB encrypt and decrypt operations, an initialization value (IV) is used. The IV is placed in the least significant bits of the DES input block with the unused bits set to '0's. This input block is processed through a DES device in the encrypt state to produce an output block. During encryption, cipher text is produced by exclusive-ORing a k-bit plain text data unit with the most significant k bits of the output block. Similarly, during decryption, plain text is produced by exclusive- ORing a k-bit unit of cipher text with the most significant k-bits of the output block. In both cases, the unused bits of the DES output block are discarded. In both cases the next input block is created by discarding the most sigificant k-bits of the previous input block, shifting the remaining bits k positions to the left and then inserting the k bits of cipher text just produced in the encryption operation or just used in the decrypt operation into the least siginificant positions. This input block is then procesed through the DES device in the encrypt state to produce the next output block. This process continues until the entire plain text message has been encrypted or until the entire cipher text message has been decrypted. (2) To use 64 or 8-bit CFB mode, take the following steps: (a) From the additional options menu, select Option 'M'. See Figure 41. (b) Select the DES Mode of choice by pressing the letter which represents the desired mode. After the current status has been updated, select another choice or return to the Additional Options menu. d. Output Feedback Mode (OFB). The output feedback mode is defined as follows: (1) A message to be encrypted is divided into data units each containing K bits. In both the OFB encrypt and decrypt operations, an initialization value (IV) is used. The IV is placed in the least significant bits of the DES input block with the unused bits set to '0's. This input block is processed through a DES device in the encrypt state to produce an output block. During encryption, cipher text is produced by exclusive-ORing a k-bit plain text data unit with the most significant k bits of the output block. Similarly, during decryption, plain text is produced by exclusive- ORing a k-bit unit of cipher text with the most significant k-bits of the output block. In both cases, the unused bits of the DES output block are discarded. In both cases the next input block is created by discarding the most sigificant k-bits of the previous input block, shifting the remaining bits k positions to the left and then inserting the k bits of cipher text just used into the least siginificant positions. This input block is then procesed through the DES device in the encrypt state to produce the next output block. This process continues until the entire plain text message has been encrypted or until the entire cipher text message has been decrypted. (2) To use 64 or 8-bit OFB mode, take the following steps: (a) From the additional options menu, select Option 'M'. See Figure 41. (b) Select the DES Mode of choice by pressing the letter which represents the desired mode. After the current status has been updated, select another choice or return to the Additional Options menu. 23. Short block processing. The ECB and CBC modes are block methods of encryption and as such, must operate on 64-bit data blocks. Partial data blocks (short blocks of less than 64-bits, or 8 characters) require special handling. The Private Line uses the following methods: a. Padding - If padding is used, The Private Line will extend the input text to be encrypted to the next whole multiple of 64-bits using whatever characters are present in the input buffer. This precludes anyone from guessing if the last block consists of mostly spaces, binary zeros, etc. The user is responsible for knowing what to expect in the decryption mode. One cannot select 'no padding' to decrypt a file which was encrypted using 'padding.' b. No Padding - If padding is not used, The Private Line will use cipher text stealing to encrypt any short block at the end of the plain text. The will maintain the integrity of the security of the encryption process. In a plain text file with a short block, the last eight characters are encrypted as a complete block. In ECB mode, the short block will consist of the characters in the short block and characters already encrypted from the previous whole block in order to make a complete block. In CBC mode, the last encrypted whole block is used to produce the DES input text for the short block which also has been lengthened by adding characters from the previously encrypted whole block to those in the short block. c. Selecting Padding choice. To use 64 or 8-bit OFB mode, take the following steps: (1) From the additional options menu, select Option 'N'. See Figure 42. (2) Select the use of padding by pressing the letter which represents the desired mode. After the current status has been updated, select another choice or return to the Additional Options menu. ____________________________________________________________________________ THE PRIVATE LINE Short Block Processing CURRENT STATUS: No Padding OPTIONS A. Do not pad short blocks B. Pad short blocks C. Return to Options Menu Enter the letter of your choice: ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Lane, Springfield, VA 22152 ____________________________________________________________________________ Figure 42. 24. Initialization value. All of the DES modes of operation used by the Private Line use an initialization value or vector (IV) except ECB. The default, or preset IV is: 12,34,56,78,90,ab,cd,ef in hexidecimal pairs. The user may change this default to one's own choice. To set a different IV, take the following steps: (1) From the additional options menu, select Option 'O'. See Figure 43. (2) Select your choice by pressing the letter which represents the desired action. After the current status has been updated, select another choice or return to the Additional Options menu. If 'Change Initial Value' is selected, the user will be prompted to enter a new IV in hexidecimal pairs. After the new IV is entered, the user will be asked to verify the new IV. If it is correct, press 'Y' and return to the Additional Options Menu. If it is incorrect, press 'N' to re-enter a new IV. A CNTRL-R will return the user to the additional options menu at anytime. ____________________________________________________________________________ THE PRIVATE LINE Initial Value CURRENT VALUE: 12,34,56,78,90,ab,cd,ef OPTIONS A. Change Initial Value B. Return to Options Menu Enter the letter of your choice: ____________________________________________________________________________ (C) Everett Enterprises, 7855 Wintercress Lane, Springfield, VA 22152 ____________________________________________________________________________ Figure 43. C. Command Line execution 1. Encryption - A file may be encrypted from the DOS prompt using an alphabetic key consisting of 1-16 characters. The key will be right-filled with blanks (hex value 20H) to the shorter of 8 or 16 characters. If 16 characters are used, the file will be doubly encrypted. To encrypt a file from the DOS prompt, take the following steps: a. Type 'private e ' followed by a file name followed by a space and an alphabtic key of 1 to 16 characters. Remember that the characters in the key are case specific. The file name may be any MS-DOS file name; it may contain a pathname specification. b. All current default switches are valid when the command line mode is used except the key type. Regardless of the key type setting, only alphabtetic keys are allowed on the command line entry. If the command line mode exits to the master menu, the current setting for the key type again takes precedence. c. Example: 'private e \tpl\msg.dat abcdefgH'. 2. Decryption - A file may be decrypted from the DOS prompt using an alphabetic key consisting of 1-16 characters. The key will be right-filled with blanks (hex value 20H) to the shorter of 8 or 16 characters. If 16 characters are used, the file will be doubly decrypted. To decrypt a file from the DOS prompt, take the following steps: a. Type 'private d ' followed by a file name followed by a space and an alphabtic key of 1 to 16 characters. Remember that the characters in the key are case specific. The file name may be any MS-DOS file name; it may contain a pathname specification. b. All current default switches are valid when the command line mode is used except the key type. Regardless of the key type setting, only alphabtetic keys are allowed on the command line entry. If the command line mode exits to the master menu, the current setting for the key type again takes precedence. c. Example: 'private d \tpl\msg.dat abcdefgH'. 3. Convert file to ASCII data - A file may be converted from binary data to ASCII which can then be sent over a telecommunications network or printed. a. Type 'private a ' followed by a file name followed by a carriage return. The file name may be any MS-DOS file name; it may contain a pathname specification. b. All current default switches are valid when the command line mode is used. c. Example: 'private a \tpl\msg.dat'. 4. Convert file to binary data. - A file may be converted from ASCII data to binary. Please note that it does not make sense to use this function unless a file has first been converted to ASCII data using The Private Line. a. Type 'private b ' followed by a file name followed by a carriage return. The file name may be any MS-DOS file name; it may contain a pathname specification. b. All current default switches are valid when the command line mode is used. c. Example: 'private b \tpl\msg.dat'. 5. Command Line Exit action - The command line mode may exit to DOS or it may exit to The Private Line Master Menu. If the current setting saved in \tpl.def indicates 'EXIT', The Private Line will return to the DOS prompt upon termination of encryption or decryption. If 'MENU' is the current setting, the command line mode will pass to the master menu upon completion of either encryption or decryption. To change the action taken upon termination of the command line option, see paragraph 20, Section II B, 'Selecting Command Line exit action.' 6. Only encryption/decryption, single or double, and convervion to and/or from ASCII to binary form, may be performed from the MS-DOS command line. All other actions must be selected from the master menu. D. Other Aspects of The Private Line 1. Selection of keys - Users should pick keys which are random and known only by the user and intended recipient. Keys such as one's nickname, spouse's name, or other keys which could be associated with either the user or the recipient, should not be used. Using one's birthday or wedding date is not a good idea. Such keys are too easy to guess. Keys should be changed as frequently as possible, depending on the criticality of the data involved. 2. Protection of keys - Keys should be afforded the same protection as the data itself. Keys should never be stored with either the clear text or the associated encrypted file. After a key has been used by The Private Line, it as well as the input and output data areas, is overwritten with binary zeroes in order to preclude a possible compromise. For obvious reasons, users should take special care not to lose or destroy keys of files which are maintained only in encrypted form. 3. Destruction of unencrypted data - Files which have been encrypted may be maintained in clear form in a safe and secure place, separate from that used to store either the keys or the encrypted file. This will protect the user against either lost keys or destruction of data because of CPU or disk failure (hopefully a rare occurence). 4. When the Private Line terminates execution, it has destroyed all data, including keys, maintained in RAM memory and input/output buffers. III. Requirements A. Hardware requirements: IBM PC, XT, AT, PS/2 or compatible. B. Software requirements: MS-DOS Operating System, Version 2.X or later, including 3.X. C. Memory requirements: 64K. IV. REFERENCES a. Bosworth, Bruce. Codes, Ciphers, and Computers. Rochelle Park, New Jersey: Hayden Book Company, 1982. b. 'Data Encryption Standard,' Federal Information Processing Standards (FIPS) Publication 46, National Bureau of Standards, U.S. Department of Commerce, Washington, D.C., January 1977. c. 'DES Modes of Operation,' Federal Information Processing Standards (FIPS) Publication 81, National Bureau of Standards, U.S. Department of Commerce, Washington, D.C., December 1980. d. 'Guidelines for Implementing and Using the NBS Data Encryption Standard,' Federal Information Processing Standards (FIPS) Publication 81, National Bureau of Standards, U.S. Department of Commerce, Washington, D.C., April 1981. e. Meyer, Carl H. and Stephen M. Matyas. Cryptography. New York: John Wiley & Sons, 1982. f. Norton, Peter. MS-DOS and PC-DOS User's Guide. Englewood Cliffs: Prentics/Hall International, 1984. g. 'Validating the Correctness of Hardware Implementations of the NBS Data Encryption Standard,' NBS Special Publication 500-20, National Bureau of Standards, U.S. Department of Commerce, Washington, D.C., Revised September 1980. V. THE PRIVATE LINE PROBLEM REPORT Date: ________________ Version #: ___________ Please Report only one problem per report. Describe your hardware and operating system. Please include disk format. Please provide a clear description of the problem and the circumstances surrounding its occurence. If possible, give an example. If a software patch or other solution is being used, please provide a complete description. This form may also be used to submit suggested enhancements to The Private Line. Problem Description: Please complete the following before submitting the form: Name: ____________________________ Phone: ______________________ Company: _______________________________________________________ Address: _______________________________________________________ City: __________________________________________________________ State: _________ ZIP:______________ Return this form to: Everett Enterprises 7855 Wintercress Lane Springfield, VA 22152 VI. Changes and Updates A. Changes. 1. Version 4.01 of The Private Line included an improved binary to ASCII conversion routine. Previous versions contained an algorithm which doubled the size of the file when converting from binary to ASCII. This version, however, increases the file only by 37%. The user must be cautioned that files converted to ASCII by earlier versions must be converted to binary by the same version before decryption can take place. 2. The other major change in Version 4.01 is an improved directory listing routine. Older versions of The Private Line only allowed the current directory to be listed. This version (4.01) allows the user to specify any pathname, including wildcard characters. 3. Version 4.02 adds an automated compliance test to determine if the program complies with the Data Encryption Standard. The test is run at program initialization time and is invisible to the user unless one of the 19 tests fail. The user may also run the compliance tests and view the results of each test by selecting option G from the additional options menu. 4. Version 4.03 added all 171 tests used by the National Bureau of Standards to verify compliance with the DES. 5. Version 4.04 contained an improved display routine and changed the encryption routine so that the encrypted file was no more than 1-7 bytes longer than the source file. Previous versions expanded the encrypted file to the end of the last 128 byte sector in the source file. 6. Version 4.05 added a routine which allowed the display of the default directory (*.*) by simply pressing RETURN. It also fixed a bug in the display directory routine which occurred if a file type contained only 1 or 2 characters. 7. Version 5.0 adds the capability of using alphabetic keys, command line execution and the following user-set default switches: a. key echo b. automatic purge of input files after encryption and/or decryption c. purge prompting of input file after encryption and/or decryption d. verify after disk writes e. key types f. re-use of existing files with or without prompts g. the number of times a file is overwritten with binary zeros before the file name is removed from the directory. 8. Version 5.0 also uses raw output mode in order to speed up The Private Line. 9. Version 6.0 adds additional modes of operation for the DES as contained in FIPS Pub 81. Specifically, the following modes are supported: a. electronic codebook (this method, with padding, is the one used by all earlier versions of The Private Line), b. cipher block chaining, c. cipher feedback (both 64 & 8 bit), and d. output feedback (both 64 & 8 bit). 10. In addition, the method of handling short blocks has been expanded to include no padding, as well as the original method of padding the message to a multiple of 8 bytes. Ciphertext stealing is the method used by both electronic codebook and cipher block chaining modes to encrypt a short block. The other DES modes do not require padding. 11. Under Version 6.0, users may specify a default initialization value, which if not changed, is set to: 12,34,56,78,90,ab,cd,ef in hexidecimal pairs. 12. The following additional user-set default switches have been added in Version 6.0: a. DES Mode of Operation b. Padding Selection c. Initialization Value 13. Beginning with Version 6.0, printed User's Guides are mailed upon registration. B. Updates. Updates to The Private Line may be obtained from the IBM Software Special Interest Group (IBMSW SIG) on CompuServe by downloading the file, TPL.ARC. This file contains all of the files associated with The Private Line, including the User Manual documentation. It is located in Data Library 0 for the first 30 days and then moved to Data Library 3. Or, one may order a diskette from Everett Enterprises, 7855 Wintercress Lane, Springfield, VA 22152, containing the latest version of The Private Line at a nominal cost of $10 (media, handling, and postage fee). Registration fees have to be paid only once. All updates are included in that one price. The nominal disk fee of $10 is due each time a diskette is obtained from Everett Enterprises.VII. INDEX command line use decryption 39 encryption 38 exit action 40 file conversion Binary to ASCII 39 ASCII to Binary 39 compliance with DES tests 23 decrypting files 9 default switches 30 changing 30 temporary 30 permament 30 original values 30 displaying disk directories 13 displaying files 9 double decryption 14 encryption 14 encrypting files 3 erasing files 22 exit, action taken upon command line 40 files ASCII 15 binary 16 contracted 16 erasing 22 expanded 15 printable 17 purging 10 re-use 31 automatic 31 with prompts 31 invoices viii keys 28 alphabetic 28 hexidecimal 28 printing files 17 Private Line, The action upon receipt 2 floppy disk systems 2 hard disk systems 3 execution command line 38 menu 38 testing 22 VII. INDEX (continued) Private Line, The using 3 problem reports 43 purging automatic 29 with prompts 29 references 42 requirements 41 hardware 41 memory 41 software 41 trouble reports 43 user set options 30 automatic purge 29 command line exit action 40 disk write verification 17 file re-use 31 key echo 19 key type 28 number of times files overwritten 29 purge prompt 29 write verify 17