On Donnerstag, 26. Juni 2008, Alan McKinnon wrote: > On Thursday 26 June 2008, Sebastian Wiesner wrote: > > Alan McKinnon <[EMAIL PROTECTED]> at Thursday 26 June 2008, > > 10:54:43 > > > > > The calculation is quite simple - measure how quickly a specific > > > computer can match keys. Divide this into the size of the keyspace. > > > The average time to brute force a key is half that value. AFAIK > > > this still averages out at enormous numbers of years, even at > > > insane calculation rates like what RoadRunner can achieve. > > > > According to Wikipedia RoadRunner is designed for 1.7 petaflops in > > peak. Assuming for the sake of simplicity, that decryption can be > > performed within a single flop: > > > > (2^256) / (1.7 * 10^15) / 2 ~= 3.5 * 10^61 > > > > In years: > > > > 3.5 * 10^61 / 3600 / 24 / 356 ~= 10^54 > > > > Correct me if I'm wrong, but it seems impossible to me, to reduce > > this get the required amount somewhere near to the life time of a > > human being ;) > > Even with your ultra-liberal assumptions, it still comes out to: > > 1000000000000000000000000000000000000 > > times longer than the entire universe is believed to have existed thus > far (14 billion years). That is an unbelievable stupendously long > period of time. Yeah, I'd agree that brute force is utterly unfeasible > as a vector of attack. Not even the almighty NSA could ever pull that > one off as there simply aren't enough atoms in the universe to make a > supercomputer big enough. > > Numbers don't lie.
and this is why nobody uses brute force. There a better ways to crack keys. NSA has tons of experts in mathematics and cryptoanalysis. Plus very sophisticated hardware. I am sure for most ciphers they use something much more efficient than stupid brute force. -- gentoo-user@lists.gentoo.org mailing list
