Re: a challenge
On Thursday, October 18, 2001 10:52 AM, droundy@civet.berkeley.edu
> If the attacker knows the algorithm (although not the prime number) this
is
> unfortunately trivial to crack: they just have to guess the time that is
> encoded by the timestamp. :(
You're right. I solved it as if the timestamp was
unpredictable. Better to use a one-way and append
it to the plaintext. But if an MD5 digest is used, it
should probably be based on some function of the
timestamp and a secret as Hahn suggested.
-=greg
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