Patent ID: 8417960
Filing Date: 2013-04-09
Classification: H04L

Abstract:
1. A personal authentication system based on biometrics information using an encryption key, comprising: a client terminal having a fingerprint sensor and an IC card reader/writer; and an authentication server coupled via a communication channel to the client terminal; wherein, at registration of personal information for authentication, the client terminal generates a public key and a secret key forming a pair with the public key, and registers the public key in the authentication server; the client terminal reads a fingerprint image for registration of personal information for authentication with the fingerprint sensor, and extracts characteristic points in the fingerprint image; the client terminal allocates characteristic point numbers to partial images of the characteristic points in the fingerprint image, respectively, for ordering, and sets coordinate values for each characteristic point as correct coordinate values, generates dummy coordinate values different from the correct coordinate values for each of the characteristic points, generates a candidate point record including the correct coordinate values and the dummy coordinate values for each of the characteristic point numbers, and orders the characteristic points in the candidate point record; furthermore, the client terminal generates a characteristic point table including records, where each record comprises images of the characteristic points from the fingerprint and the candidate point record; divides the secret key and generates a code conversion table in which numbers of the correct coordinate values in the candidate point record corresponding to the characteristic point number obtained by dividing the secret key and partial key code corresponding to a division order are associated with each other; writes auxiliary information including the characteristic point table and the code conversion table in an IC card carried by a person to be authenticated with the IC card reader/writer; furthermore in the stage of authentication, the client terminal reads the auxiliary information from the IC card with the IC card reader/writer; reads a fingerprint image for authentication with the fingerprint sensor; extracts characteristic points in the fingerprint image; arrays the characteristic points in the fingerprint image for authentication, in the characteristic point table included in the auxiliary information according to a descending order or proximity to each characteristic point in the fingerprint image, determines whether a correct coordinate value for the candidate point record corresponding to an image of each characteristic point in the fingerprint is present with predetermined nearness to the characteristic point in the fingerprint image for authentication; obtains the partial key code corresponding to a number of the correct coordinate value in the candidate point record from the code conversion table and restores a portion of the secret key; executes the same operations for all of the images of the characteristic points in the fingerprint stored in the characteristic point table to restore the secret key; and furthermore the client terminal receives data from the authentication server, the client terminal signs the data from the authentication server with the restored secret key and transmits the data to the authentication server, while the authentication server performs authentication by verifying the transmitted signature with the public key.