公开(公告)号：CA2142794C

公开(公告)日：2001-03-13

申请号：CA2142794

申请日：1995-02-17

Applicant: IBM

Inventor： ANTUNES ERNESTO ,  BANTZ DAVID F ,  BAUCHOT FREDERIC J ,  DAL BELLO ELIANE ,  FERRAZ MARCELO ,  LEMAUT FRANCOIS ,  TAVARES BERNARDO DA SILVA A

IPC: G06F15/16 ,  G06F1/14 ,  G06F9/52 ,  G06F15/177 ,  H04B1/7156 ,  H04B7/26 ,  H04L12/28 ,  H04L7/04 ,  H04B1/713

Abstract: A wireless Local Area Network (LAN), in which each wireless adapter includes a controller and a transceiver which arc located a finite distance from each other. Each controller and transceiver has their own hop clock and hop table. A data interface which includes a command set is defined between the controller and the transceiver. The comma nd set includes commands and procedures for synchronizing the hop clocks and hop tables between the controller and the transceiver.

公开(公告)号：CA2134013A1

公开(公告)日：1995-06-04

申请号：CA2134013

申请日：1994-10-21

Applicant: IBM

Inventor： KUTTEN SHAY ,  KRAWCZYK HUGO ,  HERZBERG AMIR ,  MANSOUR YISHAY ,  BAUCHOT FREDERIC ,  BANTZ DAVID ,  DAL BELLO ELIANE

IPC: G09C1/00 ,  H04J13/00 ,  H04L9/06 ,  H04L9/08 ,  H04L9/14 ,  H04L9/16 ,  H04L9/30 ,  H04L9/32 ,  H04L9/28

Abstract: In a communications system, a method is described allowing two users having established a communication session identified by a unique session freshness proof, to transmit and validate a new value of a variable by using an exchange certificate which combines the following elements : the new value of the variable, a common secret key known by both users, an exchange counter representative of the number of values of said variable transmitted between the two users during the current communication session and a session freshness proof. Protection against potential eavesdroppers and intruders is provided by combining cryptographically the elements of the exchange certificate. Further protection is obtained by interrupting the current communication session and opening a new one characterized by a new unique session freshness proof when the exchange counter reaches its maximum value; thus avoiding the risk that the same value of the session freshness keeps being used when the exchange counter is reset to its initial value. Consequently a given pair of values of the session freshness proof and of the exchange counter will never be used more than one time, making eavesdropping and, replaying attacks from intruders more difficult. Preferably, the method used for opening a new communication session uses already known authentication methods based on the common secret key.