In New Directions in Cryptography, Diffie & Hellman proposed a theoretical construction of public-key cryptography (PKC).

In A Method for Obtaining Digital Signatures and Public Key Cryptosystems, Rivest, Shamir, and Adleman provided the first practical implementation of PKC — and introduced us to Alice and Bob.

Diffie would later call the RSA system the single most spectacular contribution to public-key cryptography.