ocr: e The entropy, in bits, in Alice's user name and password a The number of decryptions per sec ond a single machine can do m The number of machines Mike can use $m The cost per machine y The time, in seconds, across which Mike can amortize his costs; Mike must be profitable after ys seconds I 2*(e-1), the number of trial decryptions Mike must do to break one safe S =t/ (m - - d), the time, in seconds, it takes Mike to break one safe, on the average $s =m* Sm ly, the total expense per second Mike must exc eed $C Ss *s= 2*(e-1)*Sm - d'y, the cost per safe Mike must exceed.
