Method and apparatus for centralized encryption key calculation

摘要

A system and method for encrypting transmissions between a plurality of communication nodes and a mobile station, wherein the algorithm for generating an encryption key resides within a first communications node. A second communications node requiring encryption between the node and a mobile station requests an encryption key from the first communications node through a PMAP interface interconnecting the nodes. The first node generates the encryption key and a countersign and transmits them back to the second communications node. The transmitted countersign is compared with a countersign provided by the mobile station, and if they match, transmissions from the second communications node to the mobile station are encrypted using the provided key.