GPG and PGP

[David Shaw]

On Mar 15, 2011, at 11:28 PM, Ben McGinnes wrote:

> On 16/03/11 10:42 AM, David Shaw wrote:
>> 
>> GnuPG does the MDC by default whenever all the keys can handle it
>> (or if the chosen cipher is 256 bits)
> 
> Is that 256 bits only or 256 bits and larger?

Strictly speaking, it's anything with a cipher blocksize that isn't 128 bits.  In the case of OpenPGP, that means AES (any of them) or Twofish.  GnuPG will flip on the MDC when it sees any of those ciphers in the preferences, or failing that, it does the blocksize test.

David