CODECRACKER!
XENOPHON WORD PATTERN DICTIONARY
BREAKS SUBSTITUTION CIPHERS WHERE FREQUENCY ANALYSIS FAILS
Frequency analysis is sometimes inadequate for solving simple substitution ciphers, for example where the message is very short, or composed of obscure synonyms of the clear with a highly unusual frequency spectrum in a deliberate effort to improve security.
What cannot be concealed however are the inherent word patterns; for example the word TRAITOR has a repetition of the first letter in the fifth position, and the second letter in the seventh. This is maintained no matter what substitutions are made, and so a cipher word with this pattern is immediately identified as TRAITOR without the necessity of a frequency analysis. A Word Patten Dictionary classifies words by their patterns, enabling the pattern to be looked up and the word identified.
Let’s see how this works. TRAITOR is reduced to its pattern by assigning letters of the alphabet, in order, to the actual letters T, R, A etc; respecting repetitions. So its pattern is abcdaeb. In fact this is a relatively common pattern, shared by Athwart, Eschews, Prosper, Remorse, Tractor and several others. Some patterns, such as Doglegged are unique. Where several words share the same pattern, it is generally clear from the type of message which word is intended. A Word Pattern Dictionary reduces all words to their patterns, and then re-sorts the patterns in dictionary order listing the real words under each pattern. There is really no short cut to this information – no computer word search or spell checker programme will do this.
Quite a lot of words, of course, do not have a pattern. This negative information is often more useful that one might think in eliminating pattern words.
No commercial publisher produces such a dictionary, the market is too small. Any that are produced are small-scale craft productions with low print runs - this one is 87 A4 sides containing 63,547 words up to 12 letters in 5,271 patterns, generated from a 75,000 word list.
THIS IS VIRTUALLY UNOBTAINABLE INFORMATION THAT ANYONE INTERESTED IN CRYPTOGRAPHY SHOULD POSSESS.
Copyright 2014 and obtainable from Roger J Morgan wolstan-dixie@hotmail.co.uk
A small sample: