On 20-8-2015 13:49, James Starkey wrote: > SHA1 produces a 160 bit hash or 2^160 possible values. To search the > hash space, on average you have to try half of these, or 2^159 probles. > A decimal digit requires about three and a half bits, so round that up > to four. So expressing the number of probes in decimal (or hex) would > require 2^155 digits. If we assume there are four billion computers on > earth. That means that each computer would need to store 2^123 digits. > A gigabyte is 2^9, so each compuer would have to have 2^114 GB of memory. > > The probability of breaking the hash is the reciprical of that number, > which will have approximately that number of zeros after the decinal > point. For convenience, lets assume that the probability of guessing a > SHA-256 hash is zero, so the difference between SHA-1 and SHA-256 is the > same as the probablity of guessing a SHA-1 hash, which is a number too > small to be expressed except exponentially.
Ah, now I see, thanks! Mark -- Mark Rotteveel ------------------------------------------------------------------------------ Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
