Patent ID: 8086868
Filing Date: 2011-12-27
Classification: H04L

Abstract:
1. A data communication method, said data communication method being of the public-key cryptography type for both authenticating users that transmit and receive data by way of a network and for encrypting said data for transmission and reception; said data communication method comprising the steps of: acquiring biometrics data of said users by using a biometrics acquisition device for acquiring biometrics data in which biological information of said users has been converted to numerical values; transmitting biometrics data, that have been acquired as inquiry data for authenticating said users from user terminal devices used by said users, to a server device; said server device, based on registration data which are biometrics data of said users that have been registered in advance in a database and said inquiry data that have been received from said user terminal devices, uses a prescribed function to calculate for each said user similarity information that indicates the degree of similarity between said inquiry data and said registration data; and said server device transmits to each user terminal device the registration data of the user that uses that user terminal device and the similarity information of the user that is the communication partner; said user terminal device, based on registration data that have been received and inquiry data that have been acquired using said biometrics acquisition device, uses the same function as said server device to calculate its own user's similarity information that indicates the degree of similarity between said registration data and said inquiry data; and said user terminal device, based on its own user's similarity information that has been calculated and the similarity information of the user that is the communication partner that has been received from said server device, uses a common function for each of said user terminal devices to generate a common secret key for decoding data that have been encrypted and transmitted from the user terminal device of said communication partner.