Patent ID: 7353385
Filing Date: 2008-04-01
Classification: H04L

Abstract:
1. A user authentication system, comprising: a data holding medium for holding a common key corresponding to a user, used in a common-key encryption method for authentication between the data holding medium held by the user and an authentication apparatus; said authentication apparatus for holding the common key used in the common-key encryption method and a private key corresponding to the user used in a public-key encryption method for authentication between the data holding medium and a server to perform a service to the user; and an information processing apparatus connected to the authentication apparatus in an always-communicable manner and provided with a function for performing authentication by the public-key encryption method; wherein said authentication apparatus is configured to receive a first data item, wherein the first data item is associated with a first authentication request from said information processing apparatus, and wherein said authentication apparatus is configured to authenticate the data holding medium by using the common key in response to the first authentication request; wherein said authentication apparatus is further configured to encrypt, only if the data holding medium is authenticated in response to the first authentication request, the first data item using the private key associated with the user and to send the encrypted first data item to the information processing apparatus; wherein said information processing apparatus is configured to decrypt the encrypted first data item using a public key associated with the user and to ensure that the decryption is successfully performed; wherein the authentication apparatus performs authentication, authenticating the data holding medium by using the common key used in the common-key encryption method for the user held by the data holding medium, wherein the additional authentication request is sent only if the decryption is successfully performed, and wherein, only when the user has been authenticated in response to the additional authentication request, the authentication apparatus performs processing, using the private key corresponding to the user, to decrypt transaction information sent from the information processing apparatus to the data holding medium, wherein transaction information encrypted by the public-key encryption method, which is sent from the information processing apparatus and forwarded to the authentication apparatus, is decrypted by the authentication apparatus using the private key corresponding to the user so as to obtain decrypted transaction information; wherein the decrypted transaction information is encrypted by the authentication apparatus using the common key; and wherein the obtained common key encrypted transaction information is sent to the data holding medium for decryption and storage.