On Mon, Jan 2, 2012 at 7:18 PM, Christian Heimes email@example.com wrote:
Am 02.01.2012 06:55, schrieb Paul McMillan:
I think Ruby uses FNV-1 with a salt, making it less vulnerable to this. FNV is otherwise similar to our existing hash function.
For the record, cryptographically strong hash functions are in the neighborhood of 400% slower than our existing hash function.
I've pushed a new patch http://hg.python.org/features/randomhash/rev/0a65d2462e0c
It seems for 32-bit version you are using pid for the two constants. Also, it's unclear why you even need to use a random constant for the final pass, you already use random constant as an initial h1, and it should be enough, no need to use for k1. Same for 128-bit: k1, k2, k3, k4 should be initialized to zero, these are key data, they don't need to be mixed with anything.
Also, I'm not sure how portable is the always_inline attribute, is it supported on all compilers and all platforms?