Keyless access control device

An identification device for a keyless authorized access control system having at least two object modules, each object module being assigned to a respective object, wherein the identification device and the object modules have respective bidirectional data communications links between them for communicating encoded data, the data communicated between the identification device and an object module being 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 identification device comprising:

• a microprocessor and a memory element, wherein the memory element stores at least two different encryption algorithms, wherein the microprocessor selects one of the stored encryption algorithms to be used for encoding the data to be communicated with an object module.

An object module for a keyless authorized access control system having an identification device and at least one other object module, each object module being assigned to a respective object, wherein the identification device and the object modules have respective bidirectional data communications links between them for communicating encoded data, the data communicated between the identification device and an object module being 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 object module comprising:

• a microprocessor and a memory element, wherein the memory element stores at least two different encryption algorithms, wherein the microprocessor selects one of the stored encryption algorithms to be used by the identification device for encoding the data communicated by the identification device and one of the object modules.