Serpent?

[Robert J. Hansen]

On 08/22/2013 01:57 AM, Frank wrote:
> My apologies if this has come up before. I notice Serpent-256 is 
> available in libgcrypt. Is it available in GPG?

No.  SERPENT is not part of the standard OpenPGP cipher profile, and
GnuPG implements the OpenPGP specification quite closely.

>From section 9.2 of RFC4880, the following symmetric cipher profiles are
defined:

	* Plaintext
	* IDEA
	* Triple DES with three independent subkeys
	* CAST5-128
	* Blowfish-128
	* AES-128
	* AES-192
	* AES-256
	* Twofish-256

GnuPG extends this with support for Camellia-128, Camellia-192 and
Camellia-256.  I don't know the reasoning for introducing Camellia, but
I'm sure there's a solid basis for it.

The best way to get GnuPG to support SERPENT is to convince the IETF
OpenPGP Working Group to add SERPENT to the symmetric cipher profiles.