ENCRYPTION COMMUNICATION APPARATUS

摘要

This invention relates to an encryption communication apparatus using encryption processing. It is an object of this invention to obtain the encryption communication apparatus with excellent tamper-resistance while ensuring sufficient securities. A communicating unit 1 sends and receives communicati on data including a length field and a data field. A length comparing unit 6 compares a value of the length field and a minimum length value stored in the apparat us in advance. When it is judged that the value of the length field is less than t he minimum length value, a controlling unit 7 controls an encryption processing unit not to perform encryption processing or decryption processing of the data in the data field.