OpenPGP enables you to have a digital signature to proof that is you that did a thing
https://www.openpgp.org/ (ZeroNet mirror not available yet)

Keybase is a site containing your social networks/profiles, with PGP signature proofing that it is yours
https://keybase.io/ (ZeroNet mirror not available yet)

Problem of Keybase: centralized and manipulated
Problem of OpenPGP: its crypto is not quantum resistant