3 ms·

nobody? This exact problem was a massive issue within the year. https://www.securityweek.com/hash-table-collision-attacks-could-trigger-ddos-massive-scale http

• masklinn 14y ago
  Using a slower hash would make the issue worse (linearly): the collisions would still be there, but now each insertion would take even more time due to the extra computational cost of the hash.
  • deleted 14y ago
    [deleted]
    • masklinn 14y ago
      > No, using a slower cryptographic hash would produce better distribution That absolutely isn't an intrinsic property of cryptographic hashes.
    • JoachimSchipper 14y ago
      EDIT: parent basically said "use a cryptographic hash". You need some kind of random salt, too - it's not that hard to find a decent number of near-collisions even in cryptographic hashes. (E.g. if your hash table doubles in size whenever two keys end up in the same bucket, an attacker needs to spend O(2^n) operations to find two keys that agree in the first n bits, which will make you do O(2^n) operations and use O(2^n) memory.)
    • dchest 14y ago
      Using a faster cryptographic hash would be better.