View Single Post
Old 01-20-2009, 09:09 AM   #7
llasram
Reticulator of Tharn
llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.llasram ought to be getting tired of karma fortunes by now.
 
llasram's Avatar
 
Posts: 618
Karma: 400000
Join Date: Jan 2007
Location: EST
Device: Sony PRS-505
Quote:
Originally Posted by ilovejedd View Post
Out of curiosity, how long would it take modern processors to generate a 56-bit key (which is what, 2^56 / 72 quadrillion possibilities)? Take, for example, a Core 2 Quad Q6600 at stock speed of 2.4GHz with all 4 cores running in parallel.
On my system (1.6 GHz clock speed) it takes roughly 10 and half seconds for calibre's LIT-specific DES implementation to churn through 20 bits of keys from Python (the DES code itself is in C). If we give a roughly 4x speedup for dropping all the way to C, give a 2x speedup for a faster core, and 4x for perfectly distributing across 4 cores, and attack the keys randomly, then it would take us on average a mere 130,489 days (upper bound of 260,979 days) per book.
llasram is offline   Reply With Quote