Patent ID: 8422680

Claim:
A method to allow secure communication among communication units, the method comprising, at a destination communication unit: receiving an encrypted transmission from a source communication unit, wherein the encrypted transmission was encrypted by the source communication unit using a source encryption key; validating the encrypted transmission by: first: identifying a first encryption key mapped within the destination communication unit as a default encryption key for the destination communication unit and associated with an identity of the destination communication unit; comparing the source encryption key to the first encryption key and determining if the source encryption key matches the first encryption key associated with the destination communication unit; and second, if the source encryption key does not match the first encryption key: identifying a second encryption key mapped within the destination communication unit as associated with an identity of the source communication unit; determining if the second encryption key is available; and if the second encryption key is available, comparing the source encryption key to the second encryption key, and determining if the source encryption key matches the second encryption key; and if it is determined that the source encryption key matches one of the first encryption key and the second encryption key, the destination communication unit processing the encrypted transmission, otherwise, the destination communication unit not processing the encrypted transmission further using any other encryption keys.