The present invention relates to a method of authenticating an individual (321) at an authenticating device (311) and an authenticating system for authenticating an individual. A basic idea of the present invention is to store, at a device or a system with which an individual wishes to authenticate herself, one or more data structures each comprising a value based on an identifier pertaining to the individual and an encrypted copy of the identifier. When the individual wants to authenticate herself, she contacts the authenticating device whereby a request is made to attain the encrypted identifier included in a specific data structure stored at the authenticating device. The individual subsequently provides proof to the authenticating device that she actually knows the identifier.
