Communication device, digital signature verification method and digital signature generation method

• US 20060177111A1
• Filed: 01/12/2006
• Published: 08/10/2006
• Est. Priority Date: 01/12/2005
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Yano, Eiji, Asai, Mao, Hamatsu, Makoto
• Granted Patent: US 7,668,335 B2
• Time in Patent Office: Days
• US Class Current: 382/119
• CPC Class Codes: G06F 21/445 by mutual authentication, e.g. between devices or programs
• CPC Class Codes: G06F 21/602 Providing cryptographic facilities or services
• CPC Class Codes: G06F 2221/2103 Challenge-response
• CPC Class Codes: G06F 2221/2129 Authenticate client device independently of the user
• CPC Class Codes: H04L 63/126 the source of the received data

Abstract

It is an object of the present invention to provide a communication device, a digital signature verification method, and a digital signature generation method, in which the memory usage efficiency is improved without confidential information required for the verification or generation of a signature being easily leaked to the outside. The Java application judges whether signature verification is required for the received signature target data. When judging that signature verification is required, the Java application outputs the received signature target data to the PKI of the platform. The PKI verifies the signature that has been added to the data output by the Java application and performs signature generation, and then notifies the Java application.

Claims

1. A communication device comprising a platform program that controls constituent elements that the device comprises, and an application that runs on the platform program and comprises a data reception function,

wherein the application judges whether signature verification is required for the received data;

the application outputs the received data to the platform program when it is judged that signature verification is required; and

the platform program performs verification of a signature that is added to the data output by the application.

2. A communication device comprising a platform program that controls the constituent elements that the device comprises, and an application that runs on the platform program and comprises a data reception function,

wherein the application judges whether it is possible for the communication device to generate a signature for the received data;

the application outputs the received data to the platform program when it is judged that signature generation can be performed by the communication device;

the platform program generates a signature for the data output by the application; and

the application transmits the signed data.

3. The communication device according to claim 2, further comprising:

an external memory that is detachable from the communication device and which generates a signature for the received data,

wherein the platform program outputs data to the external memory and generates a signature by inputting the signed data from the external memory.

4. The communication device according to claim 3, wherein the application verifies version information indicating the function of the external memory, and does not output data to the platform program when the external memory is judged not to have a predetermined function on the basis of the version information, and outputs data to the platform program when the external memory is judged to have the predetermined function on the basis of the version information.

5. The communication device according to claim 2, further comprising:

an internal memory that is contained in the communication device and which stores signature generation information for performing signature generation for the received data,

wherein the platform extracts the signature generation information from the internal memory and performs signature generation for the data by using the signature generation information.

6. A digital signature verification method of a communication device that has a platform program that controls constituent elements that the device comprises, and an application that runs on the platform program and comprises a data reception function, the method comprising:

a judging step in which the application judges whether or not signature verification is required for the received data;

an outputting step in which the application outputs received data to the platform program when it is judged in the judging step that signature verification is required; and

a verification step in which the platform program verifies a signature that is added to data output, by the application in the output step.

7. A digital signature generation method of a communication device that has a platform program that controls constituent elements that the device comprises, and an application that runs on the platform program and comprises a data reception function, the method comprising:

a judging step in which the application judges whether it is possible for the communication device to generate a signature for the received data;

an outputting step in which the application outputs the received data to the platform program when it is judged in the judging step that signature generation can be performed by the communication device;

a signature step in which the platform program generates a signature for the data output by the application in the outputting step and outputs the signed data to the application; and

a transmitting step in which the application transmits the data signed in the signature step.