INFORMATION PROCESSING DEVICE AND MESSAGE AUTHENTICATION METHOD

An information processing apparatus includes a shared information generation unit configured to generate shared information to be shared with another information processing apparatus connected via a network, a communication unit configured to receive a message, a shared information verification unit configured to compare shared information included in the message with the shared information generated by the shared information generation unit, and verify validity of the shared information included in the message on the basis of a result of the comparison, a security code generation unit configured to generate a security code based on the shared information, a security code verification unit configured to compare a security code included in the message with the security code generated by the security code generation unit, and verify correctness of the shared information included in the message on the basis of a result of the comparison, and a processing determination control unit configured to determine normality of the 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.