US Patent 9990783 Regulating vehicle access using cryptographic methods

A system and method of regulating access to a vehicle from a wireless device communicating using short-range wireless communications includes: transmitting a vehicle access certificate signing request from the wireless device to a central facility; receiving an authenticated vehicle access certificate from the central facility in response to the vehicle access certificate signing request, wherein the authenticated vehicle access certificate is signed using a central facility private key and includes the wireless device public key; transmitting the authenticated vehicle access certificate containing the wireless device public key from the wireless device to the vehicle via a short-range wireless communications protocol; receiving from the vehicle a shared secret that is encrypted by the wireless device public key; decrypting the received shared secret using a wireless device private key; generating a command controlling vehicle functions; and transmitting the command from the wireless device to the vehicle.