4 ms·

Also known as a One Time Pad for anyone wanting more info, generally the key and message are xor'd if its digital and that's the entirety of the encryption alg

• empath75 8y ago
  It’s breakable if you use some publically published document as the key as in cipher 2
  • olliej 8y ago
    The algorithm isn’t broken, the definition of a good encryption scheme is that it can’t be decrypted unless you have the key, in this case the algorithm is to substitute each letter with a lookup into a document. The non-public key is the name of the document not the document itself. Ostensibly the author decrypted the the second document by doing a brute force search of the key space (that is the set of documents available at the time). This is functionally the same as aes - just a much smaller key space.