I wrote a blog post about this.

These are the public keys we use if you want to communicate to us securely. Don't use Mastodon DMs for sensitive stuff; they're not secure (but then again, they're not supposed to be).

You can dowload these public keys and the email address(es) linked to them are contained in them.
Email public key
ProtonMail public key
PM.me public key
Threema: 3CJDR9PD
Contact Cliff if you need to get her public key or her Threema ID.
But you know what? PGP keys are cumbersome. If you know our mobile numbers, try us on Signal. We'll be really impressed if you know what to do with these Matrix addresses: