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Re: passwd hashing algorithm
From: jfh () rpp386 cactus org (John F. Haugh II)
Date: Sun, 23 Apr 95 8:18:41 CDT

Your second statement (...but its probably [ GodAwfulMany to 1 ] ...) seems
to be based on nothing but pessimism.

Not really.  The birthday attack works because you aren't picking a single
common "birthday" in advance.  You are looking at the entire population of
key,cleartext pairs.  If you pick a new second random starting point for
this attack, the probability of a match is still just as good as with the
original second random key.  Since there are 2^56 random starting points
and each of those trials will generate (one hopes ...) 2^32 unique keys in
the hash table, we can repeat this expirement 2^24 times, with each of those
2^24 times having the same high probability of success.
John F. Haugh II  [ NRA-ILA ] [ Kill Barney ] !'s: ...!cs.utexas.edu!rpp386!jfh
Ma Bell: (512) 251-2151 [GOP][DoF #17][PADI][ENTJ]   @'s: jfh () rpp386 cactus org

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