Abstract: A keyless access authorization control system includes transceivers and an identification device. The transceivers are assigned to respective objects. The identification device has a base module operable to communicate with the transceivers. For each object the identification device has a respective memory chip containing a code attuned to the object. The identification device further has an object module(s). The object module(s) is assigned to a respective one of the objects and has a memory chip having the code attuned to the respective object. The object module(s) is interchangeably connected to the base module through an interface(s) in order to communicate the code(s) to the transceiver(s) assigned to the object(s).

Abstract: A keyless authorized access control system includes object modules and an identification device. The identification device has a microprocessor and memory. The identification device and the object modules have respective communications links between them for communicating encoded data. The data is encoded using an encryption algorithm that is used to perform a symmetric encryption method which uses an encryption parameter respectively assigned to the object module. The memory of each identification device stores different encryption algorithms. The microprocessor of an identification device selects one of the stored encryption algorithms to be used for encoding the data to be communicated between the identification device and an object module. Instead of the identification device, one of the object modules may have the memory and selects one of the stored encryption algorithms to be used by the identification device for encoding the data communicated by the identification device and an object module.