High Quality Content by WIKIPEDIA articles! Keysigning refers to digitally signing someone else`s public key using your own. A more correct term would be certificate signing, since the actual key material is not changed by the process of signing. However, in the PGP community it is customary not to distinguish in speaking between someone`s key and certificate, and the term keysigning is used. (The term PGP refers here to all implementations of the OpenPGP standard, such as GnuPG.)