Robert Hogan wrote:
I remember hearing somewhere recently that someone had devised a method of
reversing SHA using cached data. ...
Memory is like that, people often remember things that never
happened. ;-)
Perhaps you mean keeping a dictionary of texts, indexed by
their message digest? Here's an exercise for you -- how
many possible texts are there composed of 1048576 bytes or
less, given a 256-character alphabet?
It's a large number, at least when compared to other large
numbers, such as the number of atoms in the universe, etc.
I think it's around 500,000 decimal digits.
Here's another exercise -- I have a hash function that
hashes all possible input strings to a single byte. Can you
think of a way to recover a text given a hash? Hint: it's
not a 1-1 function.
______________________________________________________________________
OpenSSL Project http://www.openssl.org
User Support Mailing List [EMAIL PROTECTED]
Automated List Manager [EMAIL PROTECTED]
