Abstract: A physical access control system enables acceptable portal entry codes upon receiving each physical access request by operating on the elapsed time from a previous physical access request to generate a temporal credential. The controller receives a plurality of physical access requests from a plurality of mobile application devices. Upon authenticating the first access request, the controller eliminates repetition from the space of acceptable successor requests from each mobile application device. Monotonic nonces advance the range of temporal code matches. Entry code generation is decentralized to distributed application devices and is inherently unknowable until a successor access request is initiated by the same application device.

Abstract: A method operates a server that is coupled to a network controlling door actuators at physical geo-locations. The server receives through a wireless communication network a request to enable physical access at a portal using a secure channel and a geo-location estimate from a mobile device. A circuit of the mobile device receives radio signal magnitude, phase, and power from at least one transmitter and authentication input from a user interface. Dual secured communications paths protect the server on its separately provisioned request channel and actuator command channel. Each legacy electronically controlled access portal is enabled to support smartphones without installing a replacement multi-band radio frequency reader at the geo-location.