Cryptogram Projects

I like puzzles. One class of puzzles that is fun to do that is also amenable to computer aid in solution is that of cryptograms. In my old website, I had a few simple crytogram related web tools, but I think they were not well appreciated since they were buried quite deep among many other ``computer programming'' related things.

So now, we have a special section dedicated to cryptogram tools.

Cryptogram Tools

After spending some time, I have managed to port the old cryptogram tools over. These tools are for messing with traditional cryptograms of the substitution variety. These tools do not have auto-solving capabilities.

  1. Preprocessor to generate only stream of letters.
  2. ROT13 cipher.
  3. Caesar-shift cipher.
  4. Mono-alphabetic substitution cipher.
  5. Vigenère Cipher (poly-alphabetic substitution with Caesar-shift ciphers).
  6. Poly-alphabetic substitution cipher.

Some other important points to note about these tools:

  1. They all assume the use of the standard English alphabet, i.e. A-Z and a-z.
  2. Many Latin-extended characters are conflated to their base character class. So things like `À' and `Á' are considered as letter `A'.
  3. Enciphering and deciphering preserves the case of the text.
  4. Keys are not case sensitive.
  5. Keys (especially for the mono-alphabetic family ciphers) are ``compressed'', i.e. they retain the same order of letters that appear, with duplicates removed, before being padded with what is left of the alphabet. So the key ``squeamish ossifrage'' becomes ``squeamihofrgbcdjklnptvwxyz''.

Naturally, the details of each cipher can be found in their own pages.