"Simpson, Sam" <s(_dot_)simpson(_at_)mia(_dot_)co(_dot_)uk> writes:
cipher is a Good Thing, but the point of this message is to ask
"why the choice of Twofish?"
Twofish has not been chossen as the AES algorithm for OpenPGP but
just as another optional algorithm. The only required algorithm
is 3DES - all others are optional. Leaving out CAST5, there are only
two other algorithms: IDEA which can't be used due to patent
restrictions and Blowfish which has a someone strange design but is
much faster than 3DES. According to Schneier, we should replace
Blowfish by Twofish right now because he (and others too) trusts
Thwofish more. The algorithm identifiers for AES are still reserved.
Anayway it it optional and noone is required to implement it. The
preference system gives every user/implementor a chance to disallow
optional algorithms.
My main concern is that naive users will see "Twofish" &
"Schneier" and create keys specifying this algorithm. Sure, the
How can a user create keys? The symmetric ciphers are only used for
session keys and if you have the requirement for really secure
encryption you won't use PK but use 2 symmetric algorithms in turn
with 2 randomly created passphrases.
More on AES in 2 weeks.
--
Werner Koch at guug.de www.gnupg.org keyid 621CC013