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