1. A method for protecting data having an authentication phase comprising the following steps: (a) providing a biometric feature; (b) digitizing the biometric feature to create digitized biometric authentication feature data; (c) recovering initialization biometric feature data measured in an initialization phase from said biometric authentication feature data on the basis of a coding-theory method within a freely selectable tolerance interval; (d) decrypting an encrypted code word on the basis of the recovered initialization biometric feature data thereby obtaining a decrypted code word, and; (e) recovering secret data from the decrypted code word; wherein said encrypted code word is formed by digitizing a biometric feature to create a digital representation of the biometric feature, fault-tolerantly encoding and encrypting the secret data on the basis of the digital representation of the biometric feature.