The archetypal individuals used as
examples in discussions of cryptographic protocols. Originally,
theorists would say something like: "A communicates with someone
who claims to be B, So to be sure, A tests that B knows a secret
number K. So A sends to B a random number X. B then forms Y by
encrypting X under key K and sends Y back to A" Because this sort
of thing is is quite hard to follow, theorists stopped using the
unadorned letters A and B to represent the main players and started
calling them Alice and Bob. So now we say "Alice communicates with
someone claiming to be Bob, and to be sure, So Alice tests that Bob
knows a secret number K. Alice sends to Bob a random number X. Bob
then forms Y by encrypting X under key K and sends Y back to
Alice". A whole mythology rapidly grew up around Alice and Bob;
see http://www.conceptlabs.co.uk/alicebob.html.
In Bruce Schneier's definitive introductory text "Applied
Cryptography" (2nd ed., 1996, John Wiley & Sons, ISBN
0-471-11709-9) he introduces a table of dramatis personae headed by
Alice and Bob. Others include Carol (a participant in three- and
four-party protocols), Dave (a participant in four-party
protocols), Eve (an eavesdropper), Mallory (a malicious active
attacker), Trent (a trusted arbitrator), Walter (a warden), Peggy
(a prover) and Victor (a verifier). These names for roles are
either already standard or, given the wide popularity of the book,
may be expected to quickly become so.
