Transforming a pattern identifier into biometric key generators

According to a popular pattern recognition method, this paper proposes two methods to generate a secret from individual's biometric information, such as fingerprint feature points. One method is to recover a secret based on Chinese Remainder approach. Another is to fake some chaff points based on the general biometric feature points, and then recover the secret based on polynomial fitting. In order to guarantee the integrity, a message authentic code (MAC) for all the points is stored along with the points in public. Only if a user is able to re-generate a secret that matches the stored MAC, the user will be confirmed. To keep pace with the gradual change of the measured features, the secret and the points are able to be updated adaptively.