key security

Trevor Smith Trevor Smith" <
Wed Apr 10 05:24:01 2002

On Tue, 9 Apr 2002 18:14:23 -0700, (null) wrote:

>Assuming GPG's hash is sound: If a passphrase consists of _truly_ random
>characters from, say, a set of 64 printable characters such as the ones
>used for Base64 encoding, then each character contributes log_2(64) ==
>6 bits to the entropy of the passphrase.  So a 22-character passphrase
>using this approach represents 132 bits of entropy; thus at this point
>the passphrase is not the weak link in a 128 bit cryptosystem.

Sorry, as a non-technical user, I'm still at a loss. 

A scenario:

1. you have my private key but not my passphrase
2. my passphrase is:
(or something similar)
3. my key size is 1024
4. you have a message encrypted with my public key

Which is easier:

A. crack my passphrase (brute force?) to get to my private key or
B. attack the message itself, ignoring the private key?

What if my key size is 2048? 4096?

 Trevor Smith    |