Re: Added hashes.

Juuso Hukkanen wrote:

> On Tue, 13 Dec 2005 03:55:54 +0000 (UTC), daw@taverner.cs.berkeley.edu
> (David Wagner) wrote:
>
>
>>John E. Hadstate wrote:
>>
>>>Notice, however, that I am
>>>not advancing (and I do not subscribe to) the notion that
>>>the XOR of two hashes produces a hash that is more immune to
>>>attack than either constituent.
>>
>>Yup. Actually, the XOR-hash could be arbitrarily worse than either
>>of its two components (with respect to collision-resistance).
>
>
> Then XORing with other hashes should be a useful tool in searching
> preimage collisions.
>

This is the same argument that has been used to support multiple encryption.

If overlapping algorithms (ADDed, XORed, or whatever) weakened each
other, then we would see that used as an attack. So far, no examples of
such attacks exist.
Received on Fri Dec 23 20:10:04 2005