http://j5kv55yiu3rneydqn4f35kyhejbq3fhkkm7glg5nbtvxgaxthou7g2ad.onion/case-study.html
Most of the time, PGP works by two people individually,
creating a public/private key pair. They first exchange public
keys and may begin sending encrypted messages. Only the sender
and receiver’s private keys, which are never shared with anyone,
can decrypt the messages.