Igor,

Sure. But the question is how long will the entry stay in the cache? If
it's a fairly finite amount of time, the possibility of a collision
drops dramatically.

I was suggesting murmurhash as it is significantly faster than md5/sha1
and for something like a object, the cryptographic requirements are
simply not there (i.e. the cached object does not need to be encrypted).

If there is concern over collisions, something like a bloom filter or a
cuckoo hash could be used. http://en.wikipedia.org/wiki/Cuckoo_hashing

--J

Igor Sysoev wrote:

>
> I'm not expert in cryptography, but it seems to me that 128-bit MD5
> should have though not 2^64 times less collisions, but at least 10^9
> times
> less than any 64-bit hash.

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