OpenPGP

For email encryption/signing (note that the private key for this one is managed by Proton, though they claim not to have access to the password that protects it):

If better security is needed, encrypt your message to this key (which I keep offline) and send it over directly in plain text:

You can also fetch the keys via WKD. Or,

curl -s https://openpgpkey.dingthemself.com/.well-known/openpgpkey/dingthemself.com/hu/8n7kp7z3z33ssxk5e5zcya58g4o9y9az https://openpgpkey.dingthemself.com/.well-known/openpgpkey/dingthemself.com/hu/8g1e4z8b7aju56yjyd9ufqsyhndkytsr | gpg --import