Individual authentication method, individual authentication apparatus, accounting method, accounting apparatus

An authentication apparatus, comprising:

• a receiving section that receives a first identifier and a password provided to a point of service (POS) terminal by a user;
• an identification determining section that obtains a first password corresponding to said first identifier;
• a section that identifies said user by comparing the first password and said password received from the user;
• a section that obtains a second password and a second identifier corresponding to said first identifier, said second identifier comprising a mobile terminal call number of a communication terminal;
• a signal source;
• a link establishment section that establishes, for the purpose of third party authentication of said user, a communication link between the signal source and the communication terminal using the second identifier;
• a section that receives another password from the communication terminal;
• and
• an authorization section that authenticates the user when said another password matches said second password, wherein:
• the identification determining section associates the first identifier with stored corresponding information and obtains the first password from the stored corresponding information.