Cryptogram

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For the plants which reproduce by using spores, see Cryptogam.
For the album by Deerhunter, see Cryptograms (album).
For the David Mamet play, see The Cryptogram.

A cryptogram is 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.

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[edit] 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. (Reference needed)

    [edit] 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.

    [edit] Alternative meanings

    [edit] See also

    Classical cryptography
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    Ciphers: ADFGVX | Affine | Alberti | Atbash | Autokey | Bifid | Book | Caesar | Four-square | Hill | Keyword | Nihilist | Permutation | Pigpen | Playfair | Polyalphabetic | Polybius | Rail Fence | Reihenschieber | Reservehandverfahren | ROT13 | Running key | Scytale | Smithy code | Solitaire | Straddling checkerboard | Substitution | Tap Code | Transposition | Trifid | Two-square | VIC cipher | Vigenère
    Cryptanalysis: Frequency analysis | Index of coincidence
    Misc: Cryptogram | Bacon | Polybius square | Scytale | Straddling checkerboard | Tabula recta
    Cryptography
    v  d  e
    History of cryptography | Cryptanalysis | Cryptography portal | Topics in cryptography
    Symmetric-key algorithm | Block cipher | Stream cipher | Public-key cryptography | Cryptographic hash function | Message authentication code | Random numbers