The present invention relates to secret key generation and authentication methods that are based on joint randomness not shared by others (JRNSO), in which unique channel response between two communication terminals generates a secret key. Multiple network access points use a unique physical location...http://www.google.com.au/patents/US20070036353?utm_source=gb-gplus-sharePatent US20070036353 - Authentication and encryption methods using shared secret randomness in a joint channel
