Information processing apparatus and method for authenticating message

An information processing apparatus that transmits an outgoing message to another information processing apparatus connected via a network and also receives an incoming message transmitted from the other information processing apparatus, the information processing apparatus comprising:

• a shared information generation unit configured to generate shared information to be shared with the other information processing apparatus;
• a security code generation unit configured to generate a security code based on the shared information;
• a message generation unit configured to generate the outgoing message including the shared information and the security code;
• a communication unit configured to transmit the outgoing message generated by the message generation unit and also receive the incoming message;
• a shared information verification unit configured to compare shared information included in the incoming message with the shared information generated by the shared information generation unit, and verify validity of the shared information included in the incoming message on the basis of a result of the comparison;
• a security code verification unit configured to compare a security code included in the incoming message with the security code generated by the security code generation unit, and verify correctness of the shared information included in the incoming message on the basis of a result of the comparison;
• and
• a processing determination control unit configured to determine normality of the incoming message on the basis of a result of the verification by the shared information verification unit and a result of the verification by the security code verification unit.

A method for authenticating a message transmitted and received between two information processing apparatuses connected via a network, the method comprising:

• by an information processing apparatus that receives the message,
• a first processing step of generating shared information to be shared between the two information processing apparatuses;
• a second processing step of receiving the message;
• a third processing step of comparing shared information included in the message received in the second processing step with the shared information generated in the first processing step, and verifying validity of the shared information included in the message on the basis of a result of the comparison;
• a fourth processing step of generating a security code based on the shared information;
• a fifth processing step of comparing a security code included in the message received in the second processing step with the security code generated in the fourth processing step, and verifying correctness of the shared information included in the message on the basis of a result of the comparison;
• and
• a six processing step of determining normality of the message on the basis of a result of the verification in the third processing step and a result of the verification in the fifth processing step.