Patent ID: 8866585

Claim:
A method for challenge-response authentication between a reading device and a transponder based on a contactless data transmission, the method comprising the steps: transferring challenge data from a reading device to a transponder, the challenge data being transferred within a first anti-collision loop, the first anti-collision loop including one or more commands of an anti-collision method that determine transponder identification data, wherein at least one of the one or more commands contains challenge data in a data field which is used to specify transponder identification data, and at least one of the one or more commands contains a parameter value to indicate that the data field of the one or more commands contains challenge data instead of transponder identification data; recognizing via the transponder that the challenge data is contained in the received one or more commands based on the parameter value; processing via the transponder the transferred challenge data on the basis of the challenge-response authentication; and running through a second anti-collision loop after transmission of the challenge data of the first anti-collision loop; wherein, in the second anti-collision loop, response data based on the challenge-response authentication are transmitted from the transponder to the reading device by one or more responses of the anti-collision method, and wherein, in the second anti-collision loop, the response data are contained in a data field of the response, and the data field serves to transmit transponder identification data.