Authentication method of information terminal

An information terminal comprising:

• a first receiver, the first receiver receiving identification information of a terminal belonging to an authenticatee;
• a storage device, the storage device storing the identification information of the terminal belonging to the authenticatee;
• a second receiver, the second receiver receiving trust information which includes an identification tag of the terminal belonging to the authenticatee, the trust information showing that the terminal belonging to the authenticatee is authenticated by a trust information provider;
• and
• an outputting device, the outputting device outputting information for performing an identification judgment of the terminal based on the trust information and the identification information stored in the storage device.

A method for providing information electronically over a network which comprises:

• receiving trust information, the trust information including a hash value of an identification tag of a terminal belonging to an authenticatee, and including an identification tag of a terminal belonging to a trust information provider;
• storing the trust information as a trust information database record in a storage device;
• receiving the identification tag of the terminal belonging to the authenticatee from a server;
• generating a specific hash value by a calculation part, the specific hash value being generated based on the identification tag of the terminal belonging to the authenticatee;
• searching a record from the storage device by a search operation part, the record including the specific hash value;
• and
• performing an identification judgment of the terminal belonging to the authenticatee based on the identification tag of the terminal belonging to the trust information provider, the identification tag being included in the searched record.

A method of providing information electronically over a network, which comprises;

• receiving trust information which includes a calculation result of an identification tag of a terminal belonging to an authenticatee and an identification tag of a terminal belonging to a trust information provider or a hash value of the calculation result;
• storing the trust information as a trust information database record in a storage device;
• receiving the identification tag of the terminal belonging to the authenticatee from a server;
• generating a specific calculation result by a calculation part based on the identification tag of the terminal belonging to the authenticatee and the identification tag of the terminal belonging to the trust information provider;
• searching a record from the storage device by a search operation part, the record including the calculation result;
• and
• performing an identification judgment of the terminal belonging to the authenticatee based on the identification tag of the terminal belonging to the trust information provider, the identification tag being included in the searched record.

A method for providing information electronically over a network, which comprises;

• receiving trust information which includes a calculation result, the calculation result being an encryption of additional information which is added when a terminal belonging to an authenticatee is authenticated by a trust information provider, and an identification tag of the terminal belonging to the authenticatee being used as an encryption key;
• storing the trust information as a trust information database record in a storage device;
• receiving a specific identification tag of the terminal belonging to the authenticatee from a server;
• decrypting the record of the trust information database by a calculation part, the specific identification tag of the terminal belonging to the authenticatee being used as a decryption key;
• and
• performing an identification judgment of the terminal belonging to the authenticatee based on the additional information.