Computational Efficiency of GnuPG ciphers and hashes

[David Shaw]

On Mon, Oct 06, 2008 at 10:14:44AM -0500, Kevin Hilton wrote:
> Its often been mentioned on this mailing list, that 3DES is
> notoriously slow.  On the flipside, what cipher is considered the
> fastest -- or the most computationally efficient (if this term even
> applies)?  Are there similar relative results among the GnuPG hashes?

AES is probably the fastest cipher in GPG, and MD5 is probably the
fastest hash (which doesn't make it good, just fast).

Measure it yourself.  Get some big file, and do this:

for i in 2 3 4 7 8 9 10; do echo "Trying cipher $i" && time gpg \
--cipher-algo S$i --yes --batch --passphrase test --symmetric ~/my-big-file \
&& echo && echo; done

David