Patent ID: 7570764
Filing Date: 2009-08-04
Classification: H04L,H04W

Abstract:
1. A method of authenticating access of a subscriber terminal to a communication network, comprising: storing in a communication network database authentication information for said subscriber terminal for exchanging secret key information between said subscriber terminal and said communication network when said subscriber terminal accesses the communication network, said authentication information comprising a sequence number which is recalculated each time the subscriber terminal accesses the communication network; recalculating the sequence number by generating a new sequence number from a sequence number for the subscriber terminal stored in the communication network database and wherein each sequence number comprises a suffix and a prefix, the method of generating a new sequence number comprising calculating a new sequence number suffix from an existing sequence number suffix, calculating a new sequence number prefix by a randomising process if the new suffix is equal to a predetermined value, and calculating a new sequence number prefix by an algorithmic process from the prefix of the existing sequence number if the new suffix differs from said predetermined value; exchanging secret key information between said subscriber terminal and said communication network using said recalculated sequence number; and based on said exchanged secret key information, authenticating access of said subscriber terminal to the communications network.