Shareware Overload/ShartewareOverload.cdr/busi/pcode153.zip/PC-CODE2.DOC

Text File | 1984-06-07 | 6KB | 154 lines

To begin execution of PC-CODE1 or PC-CODE2, just type these names
in PC-DOS or type PC-MENU. For example:

        A> PC-MENU

The user in PC-DOS may list all documentation files by:

        A> DIR *.DOC

Also some tips on documentation can be obtained by typing in DOS:

        A> PC-HELP

PC-CODE2 is intended to encode/decode Text only. It does this
thru a process known as super-encipherment. This means that
each character of plain text (uncoded text) is both scrambled
(transposed) as well as substituted for some random "other"
character. Only printable, keybroad characters are to be used
or generated. The input and output of PC-CODE2 is line oriented;
meaning that each record can be of variable length and separated
by Carriage Return characters. PC-CODE2 deals with line oriented
data not sector oriented data as does PC-CODE1. Carriage returns
are usually generated automatically for you when you press the
ENTER or RETURN key. A Line feed character may also be generated.
To PC-CODE2 lines are physical records and they may from 0 to 255
characters in length; but for practical readability 80 characters
are usually used.

PC-CODE2 cannot encipher binary data; it is intended for
line oriented text. Each line of data must be separated
by a carriage return character. PC-CODE2 will accept and
generate printable character between CHR$(32) and CHR$(127).
The Encoded output of PC-CODE2 is suitable for printing.
There is no padding of the the input text and a header record
is added to encoded data files to indicate the version of
the program used and the time and date of encipherment.
The program will refuse to decode files it has not encoded.


PC-CODE2 code is suitable for transmission via Communications
lines without alteration.


Keys may be loaded or saved to a File (see PC-CODE1.DOC for details).
If keys are to be loaded from a file ignore the following discussion.
Two levels of security are available for either Numeric or
alphanumeric keys: "HIGH" & "LOW". It is suggested that the
first time user try "LOW" security for the first practice session.
Low security requires either 7 key numbers or 7 alphanumeric
passwords. High security requires a minimum of 25 numbers or
at least 180 characters in passwords. Low security is not
suitable to sensitive applications.


The user must provide a series of keys (a minimum of 7) which
may either be numeric (i.e. character "0123456789") or
alphanumeric which includes any character on your IBM PC
keybroad. This includes alphabetics, numerics, and special
symbols like  "!@#$%^&*()_+?:.<>[]~{}"  and so forth.
Each of these keys should be chosen at random, and each
should be different. For alphanumeric keys, the following
is a good example:


       GOOD KEY  ---> "Z$x!Un{y%C2-&"

       BAD KEY   ---> "ENGLISH WORDS"


It is very poor to use anything that could be found in a
dictionary or encyclopedia for a key.


For Numeric keys, the best choices might numbers chosen
randomly from a telephone book or a serial numbers on a
Dollar bill. It is considered unprofessional to use numbers
like - you birth date; social security number; or Military
service numbers. Of course, for testing, numbers like 1,2,3,4,
5,6,7 are great to test out the programs. No two key numbers
should be the same (number). Examples of Numeric Keys:


       GOOD KEYS  ---> 1095215    348994    2127255     871101

       BAD KEYS   ---> 1          1         84          0



Never forget your keys, or lose them as it is impossible to
decipher the outputed code. Also, never attempt to encode
and decode data with different version of these programs.


Input may be from the console keybroad (known as "CON:" ) or
from a IBM PC File. Output may also be to the console or a
file; but also output may be sent to the PC Printer (known as
"LPT1:" ).  If both input and output are data files, they
must have DIFFERENT file names.



The pseudo-random number generator used has a period of greater
than 1.98E+233 or 1.98 times Ten raised to the 233th power.
By comparison, the National Bureau of Standards DES algorithm
has a period less than 7.21E+16 (or about 2 to the 56th power).
Both PC-CODE1 and PC-CODE2 are clearly superior to the DES limits.
To visualize the scope and level of high security of PC-CODE -
imagine a Safe Door with 25 dials; and the graduations (or numbers)
all between 1 and 2,147,283,646. A normal safe might have graduations
of 1 to 100 and require 4 such numbers. The PC-CODE algorithm is
based on a MINIMUM of 775 bits (about 96 characters). I dismiss
any algorithm (regardless of Complexity) that is based on 8 or 16
characters as naive; although these would have been perfectly OK
for the state of technology in World War II. And in a very few
decades, I believe that 1.98E+233 could become inadequate against
- say the Soviet KGB. However, advances in computer software/hardware
could reduce a decade to fewer years.


The Programs PC-CODE1 and PC-CODE2 are meant to be compiled
by IBM's BASCOM Basic Compiler and NOT for IBM's BASICA.
The Micro Ware Corporation also makes a 8087 Compiler called
87BASIC (or 87BASCOM) which will increase execution speeds
many many times (maybe 11 times faster). In either case,
when these programs are compiled, the "O", "T" & "N" options
should be specified. For example:     B> A:BASCOM/O/T/N
PC-CODE2 Source code contains no BASICA line numbers except
when required by a GOTO or GOSUB statement.


The ".EXE" files provided have been compiled by the 8088 version
or IBM BASCOM. Since, double precision floating point is used
in the pseudo-random algorithm, the 8087 compiler is a must for
timely and rapid execution; especially for large files.


These programs have been copyrighted in the Public Domain and
authored by:


            Richard Nolen Colvard
            1745 Winona Blvd, Apt #21
            Los Angeles, Calif. 90027


The above material and PC-CODE software contains material relating
to the National Security of the United States of America as defined
in the United States Code. However, distribution to foreign nations
or agents is prohibited by directives of the National Security
Agency. (NOT FOR EXPORT).