Introduction: About the American Cryptyogram Association
This electronic issue of The Cryptogram will tell you about the American Cryptogram Association and explain our activities. It is your invitation to join us. Anyone with an interest in cryptography is welcome.
ACA is a nonprofit volunteer organization devoted to disseminating cryptographic knowledge. Our interest in cryptography is amateur, not professional. We date back to the 20's, and are quite unique. There is not another organization like us in the world. Our members construct problems in classical cipher systems for other members to solve without knowing the secret key. We do not get involved in secret messages of companies or governments. Members make up and solve their own creations strictly for the fun of it. Every two months our ciphers are published in the ACA journal, The Cryptogram. Each issue contains about 100 ciphers. They range from very easy to the formidable, in some sixty different systems. Some you probably have seen already, like those found on newspaper puzzle pages. Others you probably won't know unless you are experienced in the field. Even so, some of these can be worked out logically if you have an eye for patterns. You will probably need to do some studying before you can tackle still others. Below, you'll find some examples. Although they might be called puzzle ciphers today, it was not so many years ago that some of these ciphers were used in earnest. All the ciphers we work with are constructed and edited to be suitable for solving with pencil and paper. Machine ciphers and advanced computer cryptography are beyond our scope. Many members send in their solutions, and the journal publishes those records. Of course, sending in solutions is voluntary. We are not in competition; each solver competes only against oneself. The enjoyment of solving is the important thing. The Cryptogram also publishes articles on practical cryptanalysis, history of the ACA and book reviews. Many of our members are enthusiastic computer buffs and look forward to the Computer Column. Additionally, we offer a number of books and inexpensive monographs, difficult to find otherwise, which deal with various cipher systems and how to solve them. Among the pleasures of membership are corresponding with other members, here and abroad (there are members in twenty-seven countries) by mail, electronic mail and by telephone. Members also come together at our annual convention each August. Though not obligatory, you are encouraged to adopt a "nom de plume," a code name. It's partly for fun (be as imaginative as you want) but it also puts everybody on an equal footing. Our membership of almost 700 ranges from age nine to ninety in a wide variety of jobs and professions, with an even wider variety of interests. New members receive a copy of our handbook, The ACA and You. It contains an introduction to ACA, a list of jargon and terms used in our publications, and the standards used for constructing cryptograms for publication. The handbook contains descriptions of all the cipher systems appearing in The Cryptogram. Members also receive the annual directory, listing names, addresses and "noms." What do we get out of it? Lots of fun! We have the pleasure of learning the various cipher systems that have been used throughout history. There is a little of everything: history, language, math, and they all come together in cryptography. Then, there is a thrill in making sense of what appears to be a meaningless jumble. It's a form of puzzle solving a bit like crosswords, but more challenging and engrossing. Cryptography is an ideal way to keep mentally alert. If you enjoy tackling the problems below, we hope you'll join us!
KEY WORD ALPHABETS
KEYWORD ALPHABETS are used to encipher practically all simple substitution ciphers. Recovery can be a valuable aid in solving. Here are two of the most commonly used of the available eight types. K1: Plaintext alphabet contains keyword; Ciphertext alphabet normal. Pt: P O U L T R Y a b c d e f g h i j k m n q s v w x z Ct: R S T U V W X Y Z A B C D E F G H I J K L M N O P Q K2: Pt alphabet normal; Ct alphabet contains keyword. Pt: a b c d e f g h i j k l m n o p q r s t u v w x y z Ct: V W X Z K E Y B O A R D C F G H I J L M N P Q S T U ^^^^^^^^^^^^^^^
Now, for some examples and fun. Check your answers at the end of this file.CAESAR ALPHABET AND TIPS
CAESAR ALPHABET: Tips are always given in this form, and appear in capital letters, usually within parentheses. Tips are enciphered to provide extra help for solvers if needed. A Caesar tip is enciphered by moving forward or backward in the alphabet a certain number of positions. To recover, run down the alphabet until a word that makes sense appears. For the tip LQNLKOA, the next sequences would be: . . . LQNLKOA MROMLPB NSPNMQC OTQONRD PURPOSE <== QVSQPTF RWTRQUG . . .
SAMPLE ARISTOCRATS
ARISTOCRATS, most popular of the cipher types, are simple substitutions using normal word divisions. Each plaintext letter is replaced by a different ciphertext letter not equal to itself. Each cipher has a number like (A-1), title, keyword indicator, letter count in parentheses, and the constructor's "nom de plume." There may also be a tip given in parentheses. An asterisk designates a proper noun. A-1. City living. K1 (90) PRIMEOB ISZDPH *GQG EFBE KZE NZUZPJ SQQO ZE EQ EOFNN AKFA BQT YFP'A EKQTA FA AKD YFA VZAKQTA JDAAZPJ F OQTAKITN QI KFZS.
A-2. Identity crisis? K2 (96) (XVEWL) WABBITJAVGX GZJTAT HZPRBZJ, QAABJI RPZQC EZJ RKNNGA KLL IZPMZIA RPSEF, NBEFQ BR SN, QCKSRBJI, "CAX GZTX! XKS TPKNNAT XKSP NSPQA!"
SAMPLE PATRISTOCRATS
PATRISTOCRATS are similar in construction to Aristocrats, except that they do not use normal word divisions. They are presented in 5-letter groups. These ciphers are identified with numbers like (P-1), key type, letter count/number of different letters, title, clue in Caesar. The second line gives separate letter counts and an index indicating its closeness to normal 0.0675 English, or 0.0385 random. P-1. K1 (81/19) Inherited wisdom. (KFYMJW) ALCHEMYST 10DO 8FI 7H 6P 4EG 3STUY 2JNW 1BMR I.C.=0.0654JAHOF HPTFD TDGEF DSPBF IHODH TDAJF OPIMD HOFEY DIEPN OHOFW IWDSS AODID IUGYO UHOPG RIOFP IYEUG N
P-2. K2 (86/19) An eternal game (NSAJSYJI) BOATTAIL 13I 9U 8M 7V 6Y 5LOR 4BTX 3H 2CEFNSW 1K I.C.=0.0642SVUVW VRTNB XMUEI UYIHC TFLBO RIXHB OOVNM UUMUI YIIUY LMOYT YLOII IMKLY TSMRR MVUFV WMIXL BEICI IUXVR H
SAMPLE CRYPTARITMS
CRYPTARITHMS are mathematical problems in cipher, where the letters represent numbers. The number of words given with each puzzle refers to the keyword or words used to develop the original number/letter equivalence. A statement such as 0-9 indicates the range of numbers in use, in this case the decimal set (note that 0 may come first or last). C-1. Division. (Two words, 9-0) ZIPSPOILED / SOLE = DYO; - SPMII = IDNED; - IESPO = MPIL
This cryptarithm translates into the division problem: DYO ________ SOLE / SPOILED SPMII ------- IDNED IESPO ----- MPIL
SAMPLE XENOCRYPTS
XENOCRYPTS are various cipher types in different foreign languages. One does not necessarily have to be fluent in the language of the cipher in order to solve the problems. A tip is often given, in the language of the cipher. X-1. Spanish. A Naked Foot! K1 (dejada) HUMBUGFD NJE, MOHME NO SEW NKMO, TO WKHUHODNJK OAXHEKHNJDEHJETODXO YOH OD SE EHODE NO SE USEBE SE JTUHOWJKD NOQENE UKH FD UJO NOWDFNK.
X-2. French. Big is Beautiful? K2 (qui; EYB) OOBOOERQ QFNIQOOWAR GQGAIKLZA: "MQEF DEW O'KNNZWDEQRS SIAN KEF NQSWSQO MVAOQO PQBWQRRQRS AIPWRKWIQGQRS WRMKNKLZQO PQO UIKRPQO."
SAMPLE CIPHER EXCHANGE PROBLEMS
CIPHER EXCHANGE includes problems in various systems of substitution and transposition. Tips are often given to aid in solution since space limits the length of the ciphertext. Two types are outlined here. ROUTE TRANSPOSITION: A message is written into a rectangular block in one direction (horizontally, vertically, diagonally, spirally) and taken out in another direction. E.g., "Solve a good crypt today" written in horizontally and taken out vertically (in 5-letter blocks for ease of transcription): Pt: S O L V E A G O O D Ct: SACTO GROLO YDVOP AEDTY C R Y P T T O D A Y E-1. Route transposition. Oversimplification. D'PLUMEIPSXE TRRAI EERUI OYOSO SFVLE LTNRC BINWG EPHOI OOLMA RMTSD EPNME L
NULL CIPHER: This is a concealment cipher. First letters, last letters, the second letter of each word, a sequence of letters such as first-second-third, first..., letters following each vowel, etc., are some of the great variety of ways a null cipher may be constructed. Pt: HELP! Ct: THE GREAT OLD PUMPERS. In this example, the middle letter of each word is used to encipher the plaintext message. E-2. Null. Self-Reliance (his) BOATTAILELVES EARN YAMS. AGNOSTIC PRAGMATIST DIDN'T LIE. SCHOOL INSTRUCTS "ONWARD!" NECESSARY ANNOTATION OVERLOOKED.
THE ANALYST'S CORNER
ANALYST CORNER provides the challenge of real-world cryptographic problems with limited information and sparse clues. These more difficult ciphers may bend the normal rules. Longer cipher lengths prevail to allow statistical analysis and aid in solution.
SOLUTIONS TO THE SAMPLE CIPHERS:
A-1. (citypets) My friend Bob says his living... A-2. (METALIC) Newly landed Martian, seeing... P-1. (parents) By the time a man realizes that... P-2. (OXYGENATED) Monopoly was invented... C-1. 9 8 7 6 5 4 3 2 1 0 D O N E S I M P L Y X-1. (naufragio) Un dia, cerca de las doce,... X-2. (GRANDIOSE) Une expression memora-... E-1. Alt diag/diag. For every complex problem... E-2. 1st-3rd. Every man paddles his own can-... (Keywords in parentheses: K1 in lowercase K2 in UPPERCASE)AMERICAN CRYPTOGRAM ASSOCIATION Dues and Subscription Information
Regular dues for first class service are: $15 to USA, Canada & Mexico; Air Overseas (AO) mail service $20 to Western Hemisphere and Europe; Air Overseas (AO) mail service $22 to Asia-Africa (India, Israel, Mid-East) and Pacific Rim (Australia, Japan, New Zealand, Thailand). Regular dues for suface mail anywhere outside North America are $17. Annual dues of $10 are an option for those age 65+ with ten years prior membership or for students under age 18. An initial one-time fee of $5 is assessed new members. Subscriptions for business or government (library, embassy, etc.), double the regular rates. Please send dues (or write for further information) to: ACA Treasurer 1118 Via Palo Alto Aptos, CA 95003 Or if you are on the Internet computer network, send e-mail to: NORTH DECODER metzger@sage.und.nodak.edu or PRIME dan.wheeler@uc.edu ---------------------------------------------------------------------- Prepared by ARACHNE and PHOENIX with contributions by SY S. ABEND and ACA members.