Generating symmetric keys among distributed appliances, includes generating public and private values one at least one appliance, importing a public value from another appliance via an out-of-band entity, and generating a secret value as a function of the private value corresponding to the local appliance...http://www.google.com.hk/patents/US20050193203?utm_source=gb-gplus-share專利 US20050193203 - Security associations for devices
