Public-Key Cryptography


Invented (in public) in the 1970's.

Allows Alice to send a secret message to Bob without any prearranged shared secret!

In symmetric crypto, the same key "locks" the message as "unlocks" it.
In asymmetric (or "public-key") crypto, there's one key for locking, and a different key for unlocking!

Some common examples:
RSA, ElGamal, ECC