| slovo | definícia |
alice and bob
(jargon) | Alice and Bob
n.
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 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, 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 the metasyntactic
names; 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 introduced 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.
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