ACA and You : Chapter 9

ACA jargon and familiar terms

A - Aristocrat

AC - Analysts Corner.  A department of the Cm containing longer
     messages with a "setting", but no tip.

ACA - American Cryptogram Association

Aristocrat - Simple substitution cipher with retained word divisions.

Asterisk (*) - (1) Indicates a proper noun in certain ciphers.
               (2) indicates success in solving every cipher in a section
               of the Cm. (3) indicates unused letters in Xenocrypt tips.

C - Cryptarithm

Cm - abbreviation for "The Cryptogram."

Caesar - (noun) simple transposition cipher, each letter being
         shifted the same amount.
         (verb) to run each letter up or down an alphabet until a word
         is seen.

Challenge - an unusual or difficult problem.

Cipher - A system of visible secret writing.  Not a code.

Cipher Exchange - a department of the Cm containing a variety
                  of cipher types.

Code -  A special form of substitution cipher in which letters,
        words, phrases or even whole sentences are replaced by
        groups of characters chosen arbitrarily.

Completer - a solver who has completed every problem in all
            regular departments of the Cm; indicated by a * against
            the name or nom.

Con - A construction; a cipher problem.

Consonant Line - a cryptanalysis aid, in which tentatively
                 identified consonants are graphically displayed.

Contact Count - a cryptanalysis aid, enumeration of different
                letters contacted by the letter in question.

COPS - Contribution of Postage Stamps.  A voluntary donation
       of stamps or $ to help defray costs.

Crib - a clue for entry into a cryptogram. (Also "tip")

Cryptanalyst - One who solves with knowledge of the key or system.

Cryptarithm - An arithmetic problem in cipher.

Cryptogram - (Crypt); a communication in cipher.

CS - the "Computer Supplement" to "The Cryptogram".

CT - Ciphertext.

Decipher - convert cipher to plaintext without knowing the keys
           or the system.

Decrypt - convert cipher to plaintext not knowing the keys or system.

E - The Cipher Exchange.

EB - the Executive Board of the ACA.

Elcy - "Elementary Cryptanalysis"; standard text now entitled
       "Cryptanalysis" (Dover Books).

Encipher - convert plaintext to cipher.

Frequency Chart - table of occurrences of each letter in a text.

K, K1, K3M etc. - keyword types (see Chapter 7).

Kasiski - a method for obtaining the period or a periodic
          cipher.  (See "Elcy" Chap XIV)

Key - a word, phrase, series of numbers or letters, used to
      control the encipherment process.

Krewe - members of the ACA.

Literal Key - an alphabetic key.

Naturals - an instance where the cipher letter and the plain
           letter are identical.

Nom - code name (nom-de-plume) used by some members for anonymity
      and informality.

Null - a letter added to pad out text, break up double letters, etc.

Ornamental - a cipher hidden in a graphic design.

P - Patristocrat.

Patristocrat - an Aristocrat cipher in 5-letter groups, i.e. word
               divisions are suppressed.

Pattern Word - A word in which one or more letters are repeated,
               providing a clue to identity.

Periodics - ciphers in which substitutions occur in a periodic manner.

PT - Plaintext.

Plaintext - original message before encipherment (Also "cleartext").

Quagmire - A mixed alphabet periodic cipher (named for its original

Scytale - symbol of the ACA.  A tape wound on a rod. (Pron. As "Sitaly").

Simple Substitution - a cipher in which each letter of the Pt is replaced
                      by one cipher letter, the replacements being unique
                      and no letter standing for itself.

Slide - A mechanical device for aligning alphabets, used in manual
        cryptanalysis of Periodics.

Sol - a solution.

Special - an unusual or difficult problem.

Tip - A clue for entry into a cryptogram. (Also a "crib").

Tramp - A transposition cipher.

Transposition - a cipher retaining the plaintext letters in a re-arranged

Unknown - a cipher using an unspecified system.

Vigenere - a class of periodic substitution ciphers.

Vowel Line - an analytic aid similar to a Consonant Line.

X - Xenocrypt.

Xenocrypt - a foreign language cipher.