Smart card system and operating method thereof
First Claim
Patent Images
1. A smart card system comprising:
- a smart card including a security logic circuit to detect an external attack; and
a reader communicating with the smart card,wherein the security logic circuit detects the external attack by measuring an external input capacitance through an input/output pad of the smart card and comparing the external input capacitance to an input capacitance of the reader,wherein the security logic circuit comprises;
an input/output driver providing a constant current to the input/output pad; and
a capacitance measurer controlling the input/output driver to provide the constant current to the input/output pad for a predetermined time and, after providing the constant current to the input/output pad for the predetermined time, generating a control signal to inactivate communication between the smart card and the reader if a voltage of the input/output pad is lower than a reference voltage.
1 Assignment
0 Petitions
Accused Products
Abstract
A smart card system having: a smart card including a security logic circuit to detect an external attack; and a reader communicating with the smart card. The security logic circuit detects the external attack by measuring the external input capacitance through an input/output pad of the smart card and comparing the external input capacitance to the input capacitance of the reader. This improves the security of the smart card system.
-
Citations
13 Claims
-
1. A smart card system comprising:
-
a smart card including a security logic circuit to detect an external attack; and a reader communicating with the smart card, wherein the security logic circuit detects the external attack by measuring an external input capacitance through an input/output pad of the smart card and comparing the external input capacitance to an input capacitance of the reader, wherein the security logic circuit comprises; an input/output driver providing a constant current to the input/output pad; and a capacitance measurer controlling the input/output driver to provide the constant current to the input/output pad for a predetermined time and, after providing the constant current to the input/output pad for the predetermined time, generating a control signal to inactivate communication between the smart card and the reader if a voltage of the input/output pad is lower than a reference voltage. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A smart card system comprising:
-
a smart card including a security logic circuit to detect an external attack; and a reader communicating with the smart card, wherein the security logic circuit detects the external attack by measuring an external input capacitance through an input/output pad of the smart card and comparing the external input capacitance to an input capacitance of the reader; wherein the smart card transfers a predetermined capacitance value to the reader and the reader adjusts the input capacitance of the reader by the predetermined capacitance value.
-
-
7. An operating method of a smart card system including a smart card and a reader, comprising:
-
measuring an external input capacitance through an input/output pad; comparing the external input capacitance with an input capacitance of the reader; and inactivating communication from the smart card to the reader if the external input capacitance is different from the input capacitance of the reader, wherein before the measuring, transferring a predetermined capacitance value to the reader and adjusting the input capacitance of the reader in accordance with the predetermined capacitance value. - View Dependent Claims (8, 9, 10)
-
-
11. An integrated circuit card comprising:
-
a security logic circuit providing a current to a pad, measuring a voltage of the pad and generating a control signal when the voltage of the pad reaches a predetermined level; an internal circuit communicating data with an external device and inactivating the communication in response to the control signal; wherein the security logic circuit further comprises; an input/output driver providing a constant current to the input/output pad; and a capacitance measurer controlling the input/output driver to provide the constant current to the input/output pad for a predetermined time and, after providing the constant current to the input/output pad for the predetermined time, generating a control signal to inactivate communication between the smart card and a reader if a voltage of the input/output pad is lower than a reference voltage. - View Dependent Claims (12, 13)
-
Specification