Registers – Systems controlled by data bearing records – Credit or identification card systems
Reexamination Certificate
2002-11-05
2004-01-20
Lee, Diane I. (Department: 2876)
Registers
Systems controlled by data bearing records
Credit or identification card systems
C235S382000, C705S041000
Reexamination Certificate
active
06679424
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a non contact type IC card, and more particularly to a non contact type IC card allowing the protection of data stored in the card and the prevention of data falsification.
BACKGROUND ART
A non contact type IC card performing data communication with an interrogator installed outside has been used conventionally. The examples include a ticket for ski lift, a seasonal ticket for the transportation and a prepaid card.
FIG. 7
is a block diagram schematically showing a basic structure of a conventional non contact type IC card
900
. Conventional non contact type IC card
900
shown herein, which is an IC card performing data communication in a signal superposing manner, supplies power and transmits/receives information using a signal(s) having one or more frequencies received from the interrogator not shown.
Conventional non contact type IC card
900
as shown in
FIG. 7
is an example of non contact type IC cards utilizing a single frequency and includes a tuning circuit
20
, a rectifying circuit
21
, an amplifying/demodulating circuit
22
, a modulating/amplifying circuit
23
and an SP/PS conversion circuit
24
.
Tuning circuit
20
includes a coil L functioning as an antenna and a capacitor C
0
. Rectifying circuit
21
rectifies a signal received at tuning circuit
20
, thereby generates and supplies the power to each part of non contact type IC card
900
.
Amplifying/demodulating circuit
22
amplifies and demodulates data Q from an interrogator received at tuning circuit
20
. A signal output from amplifying/demodulating circuit
22
is SP-converted by SP/PS conversion circuit
24
and then is output to a main control circuit
2
described below.
With reference to
FIG. 7
, conventional non contact type IC card
900
further includes main control circuit
2
and a memory
1
.
Main control circuit
2
processes a signal output from SP/PS conversion circuit
24
. Main control circuit
2
generates data DA to be stored in memory
1
described below and designates a location (address) of memory
1
to which data DA is to be written.
Memory
1
includes normal data storage region B
1
and data protection region B
2
. Memory
1
receives data DA via a data line L
2
as well as an address signal AD via an address line L
1
indicating an address (a location to which data is to be written) to which data DA is to be written. Here, data stored in data protection region B
2
particularly requires security in order to guarantee a normal data communication and whose rewriting is inhibited. An example of such data is an ID number of an ID card holding the personal information.
In addition, main control circuit
2
reads data from designated region B
1
or data protection region B
2
of memory
1
according to the contents of data Q received from the interrogator and generates a response data A based on the read data. Response data A is PS-converted at SP/PS conversion circuit
24
, processed at modulating/amplifying circuit
23
and then transmitted to the interrogator via coil L forming the antenna.
In conventional non contact type IC card
900
, however, the rewriting (falsification) of stored data in memory
1
can be easily performed from a device other than the interrogator once the protocol of the data communication with the interrogator is decoded, therefore the security cannot be guaranteed.
Hence an object of the present invention is to provide a non contact type IC card allowing the prevention of rewriting of a storage region in which data requiring security is stored.
Another object of the present invention is to provide a highly reliable non contact type IC card through the control of rewriting of the storage region in which data requiring security is stored.
DISCLOSURE OF THE INVENTION
A non contact type IC card according to the present invention is responsive to externally applied data for performing data communication, and includes: a first storing circuit storing data requiring security; a second storing circuit storing data other than the data to be stored in the first storing circuit; a control circuit controlling for writing the data into a location in one of the first storing circuit and the second storing circuit according to a content of the data; a selection circuit selecting whether the data is to be written into the location in the first storing circuit designated by the control circuit; and a state setting circuit controlling the selection by the selection circuit, the data is written into the location in the first storing circuit designated by the control circuit when the state setting circuit is in a first state, whereas, the data is inhibited from being written into the first storing circuit designated by the control circuit when the state setting circuit is in a second state other than the first state.
In another aspect of the present invention, a non contact type IC card is responsive to externally applied data for performing data communication, and includes: a first storing circuit storing the data requiring security; a second storing circuit storing data other than the data to be stored in the first storing circuit; a control circuit controlling for writing the data into a location in one of the first storing circuit and the second storing circuit according to a content of the data; a detection circuit receiving a control signal from the control circuit and giving instruction for controlling a state of the first storing circuit; and a selection circuit receiving the instruction of the detection circuit and selecting whether the data is to be written into the location of the first storing circuit designated by the control circuit; and the control signal output from the control circuit indicates whether the first storing circuit is in a data rewriting permitted state or a data rewriting inhibited state; and the data is written into the location in the first storing circuit designated by the control circuit when the detection circuit detects that the first storing circuit is in the data rewriting permitted state, whereas the data is not written into the location in the first storing circuit designated by the control circuit when the detection circuit detects that the first storing circuit is in the data rewriting inhibited state.
In still another aspect of the present invention, a non contact type IC card performs a data communication based on an externally applied radio wave signal, and includes: a receiving circuit receiving the radio wave signal; a first storing circuit storing the data requiring security; a second storing circuit storing data other than the data to be stored in the first storing circuit; a control circuit generating the data based on the radio wave signal received at the receiving circuit and controlling for writing the data into a location in one of the first storing circuit and the second storing circuit according to a content of the generated data; a detection circuit detecting a frequency of the radio wave signal received by the receiving circuit; and a selection circuit selecting whether the data is to be written into the location in the first storing circuit designated by the control circuit based on a result of the detection by the detection circuit; and wherein the data is written into the location in the first storing circuit designated by the control circuit, when the receiving circuit receives the radio wave signal and the frequency of the radio wave signal is detected to be a first frequency by the detection circuit, whereas the data is not written into the location in the first storing circuit designated by the control circuit when the frequency of the radio wave signal is detected to be a second frequency other than the first frequency by the detection circuit.
In still another aspect of the present invention, a non contact type IC card is responsive to externally applied data for performing data communication, and includes: a first storing circuit storing the data requiring security; a second storing circuit storing data other than the data to be stored in the first stori
Chimura Shigemi
Hikita Junichi
Ikefuji Yoshihiro
Taguchi Haruo
Arent Fox Kintner & Plotkin & Kahn, PLLC
Lee Diane I.
Rohm & Co., Ltd.
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