Patent ID: 8804954

Claim:
A method for enrolling a reference datum w having n digits, executed by a calculation unit, said method comprising at least the following steps: for the enrolling, selecting an error correcting code C of a length L greater than n, the correction capacity of the error correcting code being greater than the expected number of errors between two acquisitions of the reference datum w, the correcting code having a predetermined minimum dimension corresponding to a minimum security level; generating an extended datum w e by increasing the size of the reference datum w with L-n digits making up a secret key S k ; randomly choosing a word c of the selected error correcting code C; combining the said word c with the said extended datum w e , so as to generate a datum s for reconstructing w e ; recording the datum s on a storage medium; and for reconstructing an extended reference datum w e having L digits on the basis of a noisy datum w′ having n digits, n≦L; and of a reconstruction datum s generated during the enrolling of the reference datum w, the reconstructing comprising: generating an extended noisy datum w e ′ by increasing the size of the noisy datum w′ with L-n digits making up the said key S k , combining the reconstruction datum s with the extended noisy datum w e ′ to obtain a word c′ of length L, decoding the word c′ as word c″ belonging to the code C, and combining the word c″ with the reconstruction datum s to generate a stabilized datum w s equal to the extended reference datum w e if the word c″ obtained by decoding is identical to the word c.