Re: Got Plaintext and Ciphertext ... Want Algorithm

William L. Bahn wrote:
How will a hex converter help? It clearly isn't as simple as
that. The one thing that may help is that the length of the
cipher text (in bytes) is equal to the length of the plaintext
(in characters). Since adding a character at the end of the plain
text changes even the first byte of the cipher text, it would
appear that it might be some kind of block cipher (but with the
length dependence already noted). Since the attacker appears able
to do chosen plaintext attacks, I would recommend using strings
of increasing length until block length can be determined.




So how would I actually "determine" the block length. As you say, I can use any plaintext and get the ciphertext equivalent.

This is all just satisfying curiosity now. I've decided my overall goal (writing a client capable of communicating with a once-popular online game), was impractical but this bit still has me interested.

Cheers.

Steve
.

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