The present invention relates to a method of authenticating, at a verifier (210), a device (101, 201) comprising a physical token (102), a system for performing authentication and a device comprising a physical token which provides measurable parameters. A basic idea of the present invention is to provide a secure authentication protocol in which a low-power device (101, 201), for example an RFID tag, comprising a physical token (102) in the form of a physical uncloneable function (PUF) is relieved from performing cryptographic operations or other demanding operations in terms of processing power. To this end, a PUF device (101, 201) to be authenticated verifies if it in fact is being queried by an authorized verifier. For instance, an RFID tag comprising a PUF (102) may be arranged in a banknote which a bank wishes to authenticate. This verification is based on the bank's unique ability to reveal concealed data, such as data having been created in an enrolment phase at which the RFID tag (or actually the PUF) was registered with the bank. Now, the RFID tag again challenges its PUF to create response data sent to the verifier. The verifier checks whether the response data is correct and, if so, authenticates the device comprising the physical token, since the device is able to produce response data that corresponds to response data concealed and stored in the enrolment phase.