Generating a distinguishing feature vector by means of a distinguishing feature extractor module from a raw biometric feature of the individual, the distinguishing feature vector being configured for differentiating individuals is carried out in a method. Further steps include generating a robust feature vector by means of a robust feature extractor module from the raw biometric feature of the individual; generating a cryptographic key from first auxiliary data based on the secret of the individual and optionally other data; using the robust feature vector together with second auxiliary data in a standard cryptographic module configured to perform a standard cryptographic function keyed by the cryptographic key; and binding the results produced by the standard cryptographic module and the distinguishing feature vector together as fused data by means of a modulo-N addition operation module, wherein N=2, 3, . . . , i.e. N is an integer greater than 1.