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Kao Chow Authentication v.3

Author(s): I Long Kao and Randy Chow  (1995)

Summary: Key distribution and authentication protocol. Symmetric keys cryptography with server.


This protocol is an extension of Kao Chow Authentication v.2 to encompass tickets.

Protocol specification (in common syntax)

A, B, S :   principal
Na, Nb :   number
Kab, Kbs, Kas :   key

1.   A -> S :   A, B, Na
2.   S -> B :   {A, B, Na, Kab, Kt}Kas, {A, B, Na, Kab, Kt}Kbs
3.   B -> A :   {A, B, Na, Kab, Kt}Kas, {Na, Kab}Kt, Nb, {A, B, Ta, Kab}Kbs
4.   A -> B :   {Nb, Kab}Kt, {A, B, Ta, Kab}Kbs

Description of the protocol rules

In message 3, B generates a new ticket {A, B, Ta, Kab}Kbs containing Kab and a timestamp Ta.


See Kao Chow Authentication v.1.



See also

Kao Chow Authentication v.1, Kao Chow Authentication v.2, Needham Schroeder Symmetric Key, Neumann Stubblebine.


I Lung Kao and Randy Chow. An efficient and secure authentication protocol using uncertified keys. Operating Systems Review, 29(3):14--21, 1995.
last modified 11/11/2002.
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