Re: eCryptfs Design Document

[Phillip Susi]

Phillip Hellewell wrote:
> Again I concur with Mike.  Iterative hashing is a very common technique,
> and is very effective against this type of dictionary attack.  If you
> hash 1000 times, then an attack that normally could check 1 million
> passwords per second would now only be able to check 1000 passwords per
> second.
>
> Without iterative hashing, as computers get faster, so would dictionary
> attacks, and then people would have to keep using longer and longer
> passwords to be as effective.  Iterative hashing "levels the playing
> field" in a way.


Except that I believe you can write code to compute the nth hash in O(1) 
time rather than O(n) time, so that kind of defeats the purpose, though 
I'm no expert so I could be wrong.


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