Notes for the SIMSUBK1 enciphering program:

This program was written using PowerBasic Ver. 3.5 for DOS.  It is written in such a manner that it can also be run within the QBasic environment.  For those who do not have PowerBasic, any modifications can be made in QBasic and can be saved and/or run within QBasic.

This program is easier to use than my previous programs in that this program will check the alphabets for any letters representing themselves in the cipher alphabet.  It will not allow any number greater than 25 for the amount of shift.

The first screen shows the introduction and credits for the program.

The second screen presents the rules for enciphering a simple substitution cipher according to ACA standards.  Screen 2 has the first 6 rules.

The third screen presents rules 7 - 12.

Then fourth screen presents the 13th and last rule.

The fifth screen gives an example of a simple substitution encipherment using a K1 type key.

The sixth screen asks the user for a keyword.  This can be entered in either lowercase or uppercase.  The UCASE$ function is used to convert the lowercase letters to uppercase.

The ElimDupl (Eliminate Duplicate) function joins the keyword to a straight plain alphabet.  It eliminates any duplicate letters in the joined strings reducing it to 26 letters; none of which are duplicates.  The result is a keyed alphabet.  I found the method in one of my reference books on QBasic.  PowerBasic has functions to accomplish the same thing, but are not usable under QBasic.

The seventh screen allows the user to shift the plain alphabet from 1 to 25 places (26 would be no shift at all).  If you should enter a number larger than 25, you will have to reenter a number between 1 and 25.  The program also automatically checks for plain alphabet letters equaling themselves in the cipher alphabet.  If such should occur, the program will not allow you to exit until no equivalencies are found.  0 (zero) must be entered to exit the shift process.

The eighth screen asks the user for the plaintext message to be enciphered.  It can be entered in either lowercase or uppercase.  The UCASE$ function will convert lowercase letters to uppercase letters.

In the encipher module, all punctuation is accepted except the quotation mark.  This can be duplicated with a doubled apostrophe ('').  Commas can be used because Line Input was used in asking for the input instead of Input alone.

The ninth screen asks the user for a crib (or tip) to aid solvers.  If the user does not desire to include one, simply press the spacebar once and then ENTER.  The crib (if one is used) is automatically shifted backwards 6 places.  For example, CRIB would be "WLCV".  The Caesar module performs this orperation.  It also allows for some punctuation and spaces.

The last screen displays the results.  It displays the keyword, the plain and cipher alphabets, the plaintext and ciphertext messages, & the crib and its caesared equivalent.  To print this screen in order to submit your message to "The Cryptogram" as a con, press "Shift and Print Screen" at the same time.  Be sure your printed is turned on; otherwise you will get an error message.

This exectable program and its source code is in the public domain and is freeware.  The only thing requested is that the authors are given credit for their work.

Feel free to use this program.  If you have any questions about this program or the source code, please e-mail me at archieb42164@yahoo.com or at archieb@nctc.com.