The Stanford researchers were interested in whether encryption could be asymmetrical. Might there be a way to send an encrypted message to someone you’d never met before, someone you didn’t even know—and be confident that they, and only they, would be able to decode it? It sounds impossible, and before 1976 most experts would have said it was.3 Then came the publication of a breakthrough paper by Whitfield Diffie and Martin Hellman;
