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
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
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.