GPG sigining speed measurements

You need to following packages installed to run this test: gnupg, bc, e.g. by

apt install gnupg bc

Measuring time

Run ./timeme.sh to obtain the results. This will use the pre-generated keys to make the tests as comparable and reproducible as possible.

Each will sign its keyid (40 bytes) with itself ten (10) times and print the key (including its type) and the resulting time for all ten runs.

To ensure a warm cache and that any necessary background processes are already running (notably gpg-agent), run the test twice on an otherwise idle system and only report the second set of results.

This is a single-threaded test, as gpg will serialize the actual private-key operation (in this case, signing) through the single gpg-agent anyway. Little is gained from running it in parallel. See doc/Cryptography.md in the igitt repository for more information and test results.