The user identifier for PGP keys is the User-ID (name and email address), and you can have any number of PGP keys for one. GnuPG lets you search for a User-ID (

The user identifier for PGP keys is the User-ID (name and email address), and you can have any number of PGP keys for one. GnuPG lets you search for a User-ID (or part thereof) with --list-key, the same is true for key servers. Each key can sign each other's identifier. What do you think is missing?