Preventing shortened lifetimes of security keys in a wireless communications security system

  • US RE47,200 E1
  • Filed: 05/21/2014
  • Issued: 01/08/2019
  • Est. Priority Date: 08/16/2001
  • Status: Expired due to Term
First Claim
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1. A method for calculating an initial security count value for a new channel in a wireless communications device, the wireless communications device comprising:

  • a first security key;

    a second security key; and

    a plurality of established channels, each established channel having a corresponding security count value and utilizing a security key, at least one of the established channels utilizing the first security key;

    the method comprising;

    assigning the second security key to the new channel;

    utilizing a first set to obtain a first value, the first set consisting of corresponding security count values of the established channels that utilize the second key, the first value being at least as great as the x most significant bits (MSBx) of a value in the first set; and

    setting the MSBx of the initial security count value for the new channel equal to the first value;

    wherein if the first set is empty, then the first value is set to a first predetermined value.

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