4 ms·

However, you will have to try real hard to do so. This is coming back up again, because it's not so hard anymore.

• z92 15y ago
  The question I care is: Is the probability of naturally occurring a collision in MD5 hashing significantly more than any other 128 bit hashing algorithm? The answer is: No.
  • JoachimSchipper 15y ago
    Sure, but if you're willing to accept lots collisions on "bad" input there are faster hashes (Bernstein and Jenkins have nice fast non-cryptographic hashes, for instance.) Non-cryptographic hash functions may be a bad idea: e.g. don't store URI parameters (?foo=bar&baz=bar) in such a hash table, or you'll be vulnerable to rather simple DoS (this was all over the internet a week or two ago.)
    • maratd 15y ago
      > there are faster hashes Yes, but none as widespread. MD5 is available in every system, on every language.
    • jbapple 15y ago
      > Non-cryptographic hash functions may be a bad idea: e.g. don't store URI parameters (?foo=bar&baz=bar) in such a hash table, or you'll be vulnerable to rather simple DoS (this was all over the internet a week or two ago.) I think universal hashing is the usual protection against that kind of attack, and I think universal hashing is not considered cryptographic: http://www.cs.rice.edu/~scrosby/hash/CrosbyWallach_UsenixSec2003/ http://www.cs.rice.edu/~scrosby/hash/CrosbyWallach_UsenixSec...