In a communication system for a secure transfer of information from a source device to a sink device in a communication session in the form of a plurality of packets from the source device to the sink device, a packet structure is used with a key check block field. During the session, the source device...http://www.google.com.au/patents/US7110546?utm_source=gb-gplus-sharePatent US7110546 - Synchronization of session keys
