Tragbarer Informationsträger

An IC card (1; 20) having a control element, memory element and other necessary components is designed to have the individual components incorporated in a multi-layered integrated circuit, with the topmost layer constituted by an analyzable element (15; 35). This design prevents the functions of the incorporated integrated circuit from being optically analyzed, thus improving the information security of the IC card (1; 20). An information processing apparatus according to the present invention executes encryption of input information and decryption of read-out information in an IC card (1; 20). This allows the same information processing apparatus to perform information encryption of different systems for different information recording media (43). Accordingly, even if a third party finds out the decryption system for or one recording medium (43), he cannot immediately decrypt information on other recording media (43), which has been recorded by the same information processing apparatus. This design is therefore effective in inhibiting the third party from reading out information stored on information recording media (43).