There's an interesting article on /. today about using hash collisions to create a denial of service. The white paper referred to in the article is a bit light on details, but I did find the premise interesting.

They specifically mention attacking Perl's hash implementation, including specific attacks for 5.6.1 and 5.8.0.

An obvious defense is to avoid putting untrusted data into a hash. Sounds easy, but associative arrays are probably already being used this way all over the place. Any ideas on workarounds and fixes to reduce the risk of being DOS'ed ?

In reply to hash collision DOS by kschwab

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