Comparing Cryptographic Key Sizes II

[Anonymous]

>I can assure you
>that in moving from a 1024 bit key to a 4096 bit key, the attackers
>job is well in excess of 50x harder.  Greatly in excess of a trillion
>trillion times harder.

First part true, second part false.  See Schneier, p.160.  Extrapolating
using GNFS factoring indicates ratio of 1E21.  If SNFS factoring becomes
possible it is much worse, ratio less than one million.