Provided is a method for proving authenticity of a device with the aid of a proof of authorization of the device, wherein the proof of authorization is provided in a first step and the integrity of identity details of the proof of authorization can be checked on the basis of a digital signature of a proof of authorization issuer, and wherein the proof of authorization has an item of hardware authentication information, and affiliation of the proof of authorization to the device is proved in a second step by means of a hardware secret of the device associated with the hardware authentication information. Two-factor authentication is therefore enabled, which authentication ties authentication of the device, in particular, to the fact that a hardware-specific secret is used for the check.