I've been doing some calculations (yes - I know I'm sad).

By my figuring, even if you were able to get hold of 100 Terahertz of

processing power, and each clock cycle was able to try a possibility on PGP

encryption, 128 bits would hold out for over 10^16 years. Is it just me, or

is the 2048 bit key that PGP recommends a bit overkill?

Calculations:

2^128 = 3.423*10^38 - number of encryption possibilities for 128 bit

encryption

3.423*10^38 / 2 = 1.701*10^38 - average number of possibilities that would

need to be tested

1.701*10^38 / 100T or 1.701*10^38 / 10^16 = 1.701*10^24 - number of

seconds required to test this many possibilities, testing at 100 Teraherz

1.701*10^24 / (60 * 60 * 24 * 365) = 5.395*10^16 - number of years

required to test this many possibilities