http://tzoz3bensgxyzs7da7lpgsn3a74h7hlbm4wa6ytq2tg6ktd57w22vqqd.onion/doc/about/openpgp_keys/signing_key_revocation/index.en.html
Let's hope that this doesn't happen very often :) Expiry There is no expiry date on revocation certificates. One way of
cancelling the revocation power is to destroy all copies of shares of 2
groups amongst B, C, or D. Invitation email Someone who has a personal trust relationship with the person being
invited sends this email.