On 24-jul-2006, at 10:02, Francis Dupont wrote:
Too weak for what?
=> direct attack against the hash (the O(2^56)).
Hm, even if you build a machine that can test 1000 hashes in parallel every microsecond, it will take you more than a year on average to find a hash collision. And when you've found one, you get to redirect traffic, which is only a denial of service attack. If you have enough money to build such a hash breaking machine and enough patience to wait for it to work, I'm sure other, more dangerous avenues of attack are also open to you...
An interesting issue is that after some 10 million hosts start using HBA, there is a 50% chance of two hosts using the same hash, i.e., sort of a distributed birthday attack.