Patent ID: 8588410

Claim:
A wireless communication system comprising: a server that maintains a plurality of seed values, each seed value having a corresponding seed identifier that uniquely identifies that seed value; and a plurality of nodes forming a local area network (LAN), at least one of the nodes being in communication with the server, each other node having a wireless communication path to said at least one node that is either a direct path or an indirect path through one or more intermediate nodes that serve as repeaters, each node storing (i) a LAN identifier that uniquely identifies that node on the network, (ii) one of the plurality of seed values, and (iii) the identifier corresponding to the seed value, each node generating a unique cryptographic key based at least in part on a combination of its LAN identifier and its stored seed value and using the unique cryptographic key to encrypt information transmitted to said at least one node, the at least one node maintaining a list of the LAN identifiers of the other nodes on the LAN and the identifiers of the respective seed values stored in those other nodes, the at least one node also storing at least some of the seed values maintained by the server together with their respective identifiers, the at least one node recreating as needed the unique cryptographic key used by each of the other nodes in order to decrypt information received from each node, whereby symmetrical key encryption can be employed within the network without the need to distribute unique cryptographic keys to each node, wherein the seed value stored in a given node may be updated by (i) the server providing a new seed value and its corresponding seed identifier to said at least one node, (ii) the at least one node using a current seed value of the given node to generate the current unique cryptographic key for that given node, encrypting the new seed value and its corresponding seed identifier with the generated cryptographic key and transmitting the encrypted new seed value and corresponding seed identifier to said given node, and (iii) the at least one node updating its list of LAN identifiers to associate the LAN identifier of the given node with the identifier of the new seed value for that given node.