Classical Ciphers Implemented by Mark Riordan
  (riordanmr@clvax1.cl.msu.edu;  1100 Parker St.  Lansing MI  48912  USA)

DETRAN
   Deciphers a columnar transposition cipher.
   See ENTRAN and MKTRNKEY.

ENTRAN
   Enciphers via columnar transposition.
   See DETRAN and MKTRNKEY.

MKTRNKEY
   Does the key preprocessing for DETRAN and ENTRAN.
   (Converts alphanumeric key into column number ordinals.)

MRRMKMON
   Does key preprocessing for simple substitution.
   Creates a cipher alphabet by writing the key phrase
   across the top of a matrix & reading the rows of the
   matrix off.	See SMPLSUB.

PLAYFAIR
   Implements the Playfair digraphic cipher, with the
   traditional simple-minded processing of the key.
   (Not what Wheatstone intended!)
   Encipher & Decipher.

SMPLSUB
   Basic simple substitution, encipher & decipher.
   See MRRMKMON.

STRADDLE
   Implements the Russian "Nihilist" simple substitution
   cipher in which a single plaintext letter is represented
   by one or two ciphertext digits.  Used in Soviet ciphers
   as recently as the 1950's.  See Kahn.  Encipher & Decipher.


CAESAR
   Very simple program to exhaustively solve a Caesar cipher
   by trying all possible keys (25 of them).

P.H
   Header file needed by some of my programs.

PERIODIC
   Implements Vigerene & similar ciphers, encipher & decipher.
   See VIGKEY.

PHRASE
   Extracts a random phrase from a file you provide.

SOLVEVIG
   Attempts to solve a Vigenere cipher by trying all keys
   in a dictionary & telling you which ones resulted in
   possible plaintext that most closely matches the characteristics
   of English.	Works surprisingly well given how simple it is.

SUBST
   PC-specific program to help you solve simple substitution
   ciphers manually.

USAGE
   Routine needed by some of my programs.

VIGKEY
