The aim of the invention is to combine the advantages of PIN-supported security systems and of security systems based on biometrics while avoiding the drawbacks associated with each of these systems. To this end, the PIN is unambiguously generated using biometrics. For generating the PIN, the invention provides that only characteristic data, which can be unambiguously reproduced, is to be derived from the determined biometric raw data. A key data record is then generated on the basis of this characteristic data that can be unambiguously reproduced. Said key data record can either represent the PIN code or can be generated from the PIN code. The PIN code, as a consequence, can always be unambiguously reproduced by means of the biometric data. As a result, the user no longer needs to memorize the PIN code and, in addition, the PIN code can not be relayed to a third party. |