Today I learned that Alice and Bob were born in 1978. Their birth was announced in the paper A Method for Obtaining Digital Signatures and Public-Key Cryptosystems by R.L. Rivest, A. Shamir, and L. Adleman.

On page 3, the paper states:

For our scenarios we suppose that A and B (also known as Alice and Bob) are two users of a public-key cryptosystem.

That was their official introduction. And, their very first scenario:

How can Bob send a private message M to Alice in a public-key cryptosystem?

For those who don’t know, Alice and Bob are the common placeholder names for the human transmitters and receivers in communications-based discussions. I believe I “met” them when first reading about quantum teleportation, during which transmitter Alice teleports an unknown quantum state to receiver Bob.

Although Alice is always the transmitter (my observation), it is interesting that the initial transmitter was actually Bob. I can’t think of any other example of Bob being the one to send the message.

Over the years, Alice and Bob have been joined by their good friend Charlie. Charlie is usually a receiver, but that’s not always the case.

I’ve also met Eve, who nobody seems to like. She loves sticking her proverbial nose in Alice’s business. Eve’s full legal name, by the way, is Eavesdropper.

In case you were wondering — and you probably weren’t — now you know.