Every time I update my personal or other people’s OpenPGP certificates, I can not remember the hostname of a public OpenPGP keyserver. This list should function as a quick reference for commonly used and (somewhat) reliable keyservers.
keys.gnupg.netkeyserver.pgp.comhttps://pgpkeys.eu/pgp.mit.edupool.sks-keyservers.net
Keyserver with data privacy in mind:
Update 2021-06-27:
Except for keys.openpgp.org, none of the above key servers seem to work correctly and reliably. The SKS keyserver pool website announced on 2021-06-21:
Due to even more GDPR takedown requests, the DNS records for the pool will no longer be provided at all.
It seems like my predictions or worries about data privacy with key servers were on point.
Update 2021-09-24:
Andrew Gallagher announced on the GnuPG development mailing list a new service based on the sks_spider software that monitors working keyservers and displays them as a nice graph:
Update 2023-03-02:
pgp.mit.edu has been unreliable and slow since years. The service has now been down for more than a week. Cybercanary remind me via encrypted mail that there are other notable key servers outside the SKS network. Just to mention one service, Proton Mail provides a keyserver for its users and also implements a Web Key Directory. I think the WKD approach has to potential to replace the keyserver infrastructure as it provides an easy and reliable way to look up keys. However, it requires a mail provider that implements a WKD or control over the DNS of the mail server.
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