Crypto is a encryption utility which may wipe out source files, launch decrypted files and automatically re-encrypt them after modification.
After I
ve read
Murgan
s Musings
in Palmtop
s issue 18 I
ve wondered how difficult it is to write an encryption utility for the EPOC platform.
I know that such a program already exists, but I was more interested in the making than in the result.
m using Crypto myself for managing a simple database with tons of logins, passwords and other figures I
m supposed to know by heart. A perfect job for my little brain extension
my beloved Series 5.
?mT?m
&paint.app
To encrypt a file:
1. Launch Crypto from your Extras bar
2. Select the file you want to be encrypted and press
Continue
3. Enter your password twice and press
Encrypt
4. Press
Close
to leave Crypto
To decrypt a file, launch and re-encrypt it:
1. Launch the encrypted file from your system screen
2. Enter your password and press
Launch
3. View and/or make the necessary changes and close the file
To decrypt a file:
1. Launch the encrypted file from your system screen
2. Enter your password and press
Decrypt
3. Press
Close
to leave Crypto
V1.14 Production
February 14, 2000
What's new?
Files are launched asynchronously so Crypto is not blocked anymore and offers a 'go to file' button
Most important buttons are arranged to the right
Crypto recognises newer Crypto files and the need of a software update
Folders and files containing space characters are fully supported
Dense packed dialogs to improve the appearance on smaller machines, e.g. the Revo
A missing password entry does not cause a crash anymore
Pressing the test button does not cause a crash anymore
Compatibility to prior releases
This release is fully compatible to prior releases
The Crypto file structure has not been changed
Files encrypted with Crypto V1.14 may be decrypted with prior releases too
Feature list
File encryption and decryption using the secure RC4 algorithm (256-bit)
Wipe out source files to make sure an undelete is useless
Cancel and resume during encryption, decryption and wipe file
Launch support for all file types (for files without a EPOC header - like zip archives, plain text files or graphics
any installed program may be selected at encryption time to open the file)
Compacting data and agenda files before encrypting files
Automatic re-encryption
Detects the need of compacting and re-encryption
General preferences for encryption mode, source file treatment after encryption and statistics.
Runs on
EPOC Release 3 (e.g. Series 5)
EPOC Release 5 (e.g. Series 5mx)
EPOC Emulator Release 5 (WINS)
Available in German, English, French, Italian, Brazilian Portuguese, Dutch and Danish
You may choose between three actions to be executed after every successful encryption of a file.
1. None
No action, the source file will be left untouched.
2. Delete source file
The source file will be deleted. This means that the directory entry of the EPOC file system will be deleted. The file contents itself may be
rescued
using an undelete utility.
3. Wipe source file
Every single byte in the source file will be replaced by an ASCII 0 character. Afterwards the source file will be deleted and it
s impossible to restore the original file contents using an undelete utility.
The processing of encryption, decryption and wipe file may be cancelled. However, you may wonder what happened and where you find your data afterwards.
Cancel encryption
The unfinished Crypto file has been deleted. Your data is stored in the unencrypted source file.
Cancel decryption
The unfinished source file has been deleted. Your data is stored in the Crypto file.
The unfinished source file may be undeleted by someone...
Cancel wipe file
The source file has been wiped out at a certain percentage and its probably gone for good. It has not been deleted and you may look at it using an appropriate tool. Your data is stored in the Crypto file.
Decrypt and re-encrypt the file to complete the wipe file process.
>pl+\
&paint.app
&paint.app
First of all I'd like to thank Fatcatz who has translated the RC4 algorithm from C to OPL. I've used his code as a pattern for the secure encryption algorithm of Crypto. Visit Fatcatz' web site at http://www.fatcatz.tm/.
The following persons have translated Crypto for free. Thank you very much!
rald Aubard - French. Visit G
rald's web site at http://www.psionist.com/
Matthias Neisser - Brazilian Portuguese. Visit Matthias' web site at http://www.geocities.com/SiliconValley/Platform/3613/
Salvo Miccich
und Filippo Zerboni
Italian. Visit Salvo's web site at http://www.scicli.com/psion/ und Filippo's web site at http://utenti.tripod.it/sit5/
Roeland Krul - Dutch. Roeland's e-mail address is rkrul@hotmail.com
Michael Degn - Danish. Michael's e-Mail Adresse is michael.degn@wanadoo.dk
And many thanks to the anonymous person who published RSA's secret RC4 algorithm to the world.
Depending on the security level you need you may choose between three different encryption modes.
1. Password only
(~ 53
900 bytes per second)
This mode stores the unmodified original file after the 61 bytes Crypto header. Using a hex-editor or another tool it doesn
t need much effort to restore the original file.
This mode is supported for compatibility to previous releases only.
2. Fast encryption
(~ 50
300 bytes per second)
This mode uses a 32-bit encryption algorithm. The first 4 characters of your password are used to build an encryption key. This means that there exists 2^32 (4
296) possibilities how a file may be encrypted. However, no big deal for a hacker, especially when a lot of Hex 00 characters are part of the source file.
This mode is supported for compatibility to previous releases only.
3. Secure encryption
(~ 44'200 bytes per second)
This mode uses a 256-bit RC4 encryption algorithm. The key is based on your password entered. Passwords are automatically extended to the maximum size of 32 characters. This means that there exists 2^256 (~115 792 089 237 300 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000) possibilities how a file may be encrypted. Of course this is a theoretical value which may be reduced radically by the fact that generally only a few lower case letters are used as a password. Use special characters as a part of your password too and be aware that the longer your password is the better is your protection.
It's strongly recommended to use this mode for all kind of files and always in combination with the wipe file option!
The values for 'bytes per second' are based on a file of 211'288 bytes. The file was encrypted on a Psion Series 5, ROM 1.01. The smaller the file the worse the performance. This is caused by the overhead for an encryption and by the buffer size which is smaller for small files to display a smoother progress bar and allow to cancel an encryption process.
>te+\
&paint.app
The Series 5 built-in programs Word and Sheet have their own password protection feature. So why use an encryption program like Crypto?
I don
t know what kind of algorithm is used in the Psion
s Word and Sheet program, but it
s a fast and an easy way to protect data. Other programs like Data, Agenda etc. do not support such a encryption feature and for this kind of files Crypto offers the encryption functionality. I recommend to use Crypto for those files only as long as the algorithm used in the built-in programs hasn
t been hacked.
By the way, Microsoft Word
s password protection of version 1 and 2 has been hacked in 1993 and
decryption
-programs may be downloaded from the internet (e.g. ftp.funet.fi:/pub/crypt/analysis/wordunp.zip). Microsoft
s Word 98 does not support encryption anymore even though passwords for read and write access may be defined...
&paint.app
Crypto uses its own format to store the encrypted data. You can split the file in the following two parts:
Header
Position 01..24: EPOC UIDs
Position 25..26: Crypto mode
Position 27..28: Action after encryption
Position 29..61: Encrypted password (using the 256-bit RC4 encryption algorithm regardless of the specified Crypto mode)
Position 62..EOF: Encrypted data according the Crypto mode used
When the file was encrypted in
Password only
mode, simply delete the Crypto header to get your source file back.
&paint.app
You should carefully read the following terms and conditions before using this software. Unless you have a different license agreement signed by Philipp R. Salvisberg, Switzerland your use of this software indicates your acceptance of this license agreement and warranty.
Freeware license
Crypto is freeware but not public domain. You are hereby licensed to use this software for personal use only. You may not alter or modify Crypto and cannot give anyone else permission to do so. Under no circumstances are you licensed to distribute this software.
Disclaimer of warranty
This software and the accompanying files are provided
as is
and without warranties whether expressed or implied. The user must assume the entire risk of using this software. The author shall not be held liable in any way for any damage that may occur as a result of using this software.
Copyright
Crypto V1.14 Copyright
1998-2000
by Philipp R. Salvisberg, Switzerland
All rights reserved.
Change file in launched program
If you create a new file or change the file in the launched program the re-encryption process won
t be started. In this case Crypto waits for the program to be closed before the re-encryption process starts.
Close the program to allow Crypto to re-encrypt the file before you start working on another file.
Use the Fn key to launch a second instance of the program to work on several files.
Crash in file dialog
Crypto crashes when pressing Tab in the folder field when the file dialog was initi
alized with a system folder. This is a known OPL bug in ROM 1.00 and 1.01.
Change the disk. Afterwards you may use Tab without causing a crash.
System folders not accessible
The system folders are not shown in the file dialog when the dialog was initialized with a non system folder.
Change disk or use Tab. Afterwards the system folders will be available.
More?
Have you found additional limitations or bugs? Please don't hesitate to contact me via e-mail. Thank you!
&paint.app
&paint.app
&paint.app
&paint.app
Your password is the key to the encrypted data. It is strongly recommended to use special characters like
-#$!~
as a part of your password. Use long passwords (up to 32 characters) for better protection.
However, you should be able to remember your password, otherwise you have to be a hacker to get your data back. Please don
t ask me, because I cannot help you!
In this dialog the items
Crypto mode
and
Action after encryption
are defining the preferred value for new Crypto files.
The following values are valid for the
Show statistics after ... (secs)
items:
Statistics dialog will not be displayed
Statistics dialog will be displayed and has to be closed by user action.
1..120
The statistics dialog will be displayed for the specified seconds and closed automatically afterwards. The dialog may be closed by user action too.
IntroductionR
CryptoUK!
Quick startR
CryptoUK!
Release InformationR
CryptoUK!
Action after encryptionR
CryptoUK!
Cancel processingR
CryptoUK!
CreditsR
CryptoUK!
Crypto modesR
CryptoUK!
7Difference to the password protection of Word and SheetR
CryptoUK!
FeedbackR
Do you have bug reports, enhancement requests or comments?
Your Feedback is very appreciated.
Thank you!
e-mail: philipp@salvis.com
www: http://salvis.com/
CryptoUK!
File formatR
CryptoUK!
File, Folder, DiskR
In the main dialog any file may be selected, even Crypto files. The processing depends on the chosen file type:
(.txt)