cryptogram n : a piece of writing in code or cipher [syn: cryptograph, secret writing]

English

Noun

1. A type of word puzzle in which text encoded by a simple cipher is to be decoded.

A cryptogram is a type of puzzle which consists of a short piece of text encrypted with a simple substitution cipher in which each letter is replaced by a different letter. To solve the puzzle, one must recover the original lettering. Though once used in more serious applications, they are now mainly printed for entertainment in newspapers and magazines. There is also a type of cryptogram in which you have an already written article and you number each word. The first word would be One and the second would be Two... Then you write the cryptogram using the numbers of the first letter of that number's word. example; 1.hi 2how 3are 4you? 2-3-4 would be h-a-y. This is harder because the article has to have a word for every letter in the cryptogram. The person decoding would have to have the article and number it to solve the cryptogram.

History of cryptograms

Cryptograms were not originally created for entertainment purposes, but in the Spartan military in fifth century B.C. This code consisted of a staff around which a strip of paper was wrapped without overlapping. A message was written on the paper, which was then unwrapped and sent on its way. The message could only be correctly decoded with the right diameter of stick. Julius Caesar invented the first substitution cypher, one which still bears his name.

The first use of the cryptogram for entertainment purposes occurred during the Middle Ages by monks who had spare time for intellectual games. A manuscript found at Bamberg states that Irish visitors to the court of Merfyn Frych ap Gwriad (died 844), king of Gwynedd in Wales were given a cryptogram which could only be solved by transposing the letters from Latin into Greek. Around the thirteenth century, the English monk Roger Bacon wrote a book in which he listed seven cipher methods, and stated that "a man is crazy who writes a secret in any other way than one which will conceal it from the vulgar." During the Renaissance, cryptograms were used to political ends.

The best-known example of cryptograms in contemporary culture is the syndicated newspaper puzzle Cryptoquip.

Cryptograph Secret Key

A public key cryptograph communication technology which can be verified to be secure even when an attacker to the public key cryptograph selects a random function giving random oracle is provided. A sender side apparatus 100 generates a cipher text so that it is difficult to calculate from the cipher text partial information with regard to an input value (not finite to message) to a random function as random oracle used in generating the cipher text. And the apparatus 100 generates verification data for verifying that the apparatus 100 knows the input value to the random function, as a unit of the cipher text. Then, the apparatus 100 transmits the cipher text to a receiver side apparatus 200. The receiver side apparatus 200 outputs a result of decrypting the cipher text when the verification data included in the received cipher text can be correctly verified.

Solving a cryptogram

This is usually done by frequency analysis and by recognizing letter patterns in words, such as one letter words, which, in English, can only be "i" or "a" (and sometimes "o"). Double letters, apostrophes, and the fact that no letter can substitute for itself in the cypher also offer clues to the solution. Occasionally cryptogram puzzle makers will start the solver off with a few letters. The Cryptogram is also the name of the periodic publication of the American Cryptogram Association (ACA), which contains a large number of cryptographic puzzles.

References

• Martín Gil F.J., Martín Ramos P., Martín-Gil J. "A cryptogram in the compass roses of the Majorcan portolan charts from the Messina-Naples mapmakers school". Almogaren, Nº. 36, 2005, pags. 285-296

See also

• List of famous ciphertexts
• American Cryptogram Association