Re: discover encryption method

[Alexander Klimov <alserkli () inbox ru>]

On Tue, 8 Jan 2008 richard () tortoise demon co uk wrote:
> I can't see anything repeated here, or any constant difference.

First of all we can confirm that this "encryption" is done by a
novice. Only 16 letters are used and the length is always even (in
fact it is 2 mod 4), so I suspect that the output encoding is simply
usual hexadecimal notation of bytes with digits replaced by letters.
The distribution of values is very biased: the first 5 values are used
much more often than the rest, 0 is used 209 times, while 1-4 are used
155-187 times, and the rest are used at most 119 times. What bothers
me is that the length of the ciphertext is not monotonically
increasing:

 166 a
 186 aa
 210 aaa
 174 aaaa
 198 aaaaa

 190 b
 186 bb
 178 bbb
 174 bbbb
 198 bbbbb

Maybe there is some additional information encoded together with
the encryption of a password. I think you should test that the
same password always results in the same ciphertext. You should also
consider sending it to a cryptography list -- there will be much more
people who like to spend time on such puzzles.

-- 
Regards,
ASK