[Python-Dev] Hashing proposal: 64-bit hash

Frank Sievertsen pydev at sievertsen.de
Fri Jan 27 22:08:37 CET 2012


> As already mentioned, the vulnerability of 64-bit Python rather theoretical and not practical. The size of the hash makes the attack is extremely unlikely.

Unfortunately this assumption is not correct. It works very good with
64bit-hashing.

It's much harder to create (efficiently) 64-bit hash-collisions.
But I managed to do so and created strings with
a length of 16 (6-bit)-characters (a-z,  A-Z, 0-9, _, .). Even
14 characters would have been enough.

You need less than twice as many characters for the same effect as in
the 32bit-world.

Frank





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