Wrong access preventing system of ic card

Abstract

Abstract PURPOSE:To prevent a wrong access by providing dummy contacts independently of normal contacts of an IC card and preventing the effective access to an internal circuit if these dummy contacts are accessed. CONSTITUTION:When a power source is turned on, it is discriminated whether any of dummy contacts 30-34 is accessed or not. If it is accessed, this access is regarded as wrong, and a wrong access flag MA of an ROM21 is set. Only when dummy contacts 30-34 are not accessed at all and the wrong access flag MA is not set after the power source is turned on, a response signal of access start OK is sent to an external device. When receiving this response, the external device sends prescribed access data to the IC card to perform prescribed operation processings such as storage into a memory, etc. When an access end signal comes from the external device, the response signal of access end OK is transmitted to terminate the operation.

Inventors

• 👤 Yoshitaka Sano
• 👤 義隆 佐野

Bibliographic Details