Is there any software that can output all possible solutions to a substitution cipher? I have a 34 character substitution cipher as follows: ABHIJCKDELMFNOEPQ RDSTUVWGFADBXCYGZ

15 of the characters in the cipher are repeated. I would like a software to output all possible word combinations that will fit the cipher (English words only). I know there will be thousands, maybe millions, of possibilities but I need to evaluate each possibility.

Do you know of such a software?

  • $\begingroup$ I’m voting to close this question because this is more about [software-recommendations.se] than a cryptographic question; simply asking for libraries or resources is considered off topic. $\endgroup$
    – Maarten Bodewes
    Feb 2 at 20:57

1 Answer 1


Yes. Another name for a substitution cipher is a cryptogram, which are popular recreational puzzles. There are several on-line cryptogram solvers. Here are two that do what you ask:

If you wanted to write your own software to analyze the ciphertext, then you just need a word-list. For each word in the word-list, you create and store a canonical encoding: e.g. "people" becomes "abcadb". To determine if the first word of plaintext could be "people", you can then apply the same encoding to the first six letters of ciphertext and then compare.

Note that the example ciphertext provided has some unusual structure. It may not be a pure substitution cipher:


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