Telephone having authentication function and telephone system

Abstract

An information processing terminal includes a calculation processing unit, a telephone communication processing unit for performing a telephone communication with respect to another appliance, a communication processing unit for performing a communication operation with respect to the another appliance, and a signature calculating unit in which when a telephone communication with respect to the above-described another appliance is carried out, a signature using a secret key is produced by the calculation processing unit, and the signature calculating unit produces information attached with signature to which the produced signature has been attached. In the information processing terminal, the telephone communication processing unit transmits the information attached with signature to the another appliance corresponding to a telephone calling destination. It then becomes possible to notify that a telephone communication counter party is a justified user of an appliance before the telephone communication is commenced.