COMMUNICATION APPARATUS, CONTROL METHOD THEREOF AND COMPUTER READABLE MEDIUM

• US 20080120506A1
• Filed: 11/05/2007
• Published: 05/22/2008
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamauchi, Hisayuki, Ogasawara, Taku
• Granted Patent: US 7,987,375 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823

Abstract

If electronic certificate data containing a private key and public key to be used to add an electronic signature to data with timer transmission setting is deleted, no electronic signature can be added at the set timer transmission time. To accomplish this, when timer transmission and electronic signature addition using stored key information and electronic certificate are set for transmission target data (YES in S38), deletion of the stored key information and electronic certificate to be used for generating an electronic signature is restricted (S40).

Claims

1. A communication apparatus having a function of transmitting data at a designated time, comprising:

a storage unit configured to store generation information to be used for generating an electronic signature;

a signature generation unit configured to generate the electronic signature by using the generation information;

a delete unit configured to delete the generation information;

a transmission reserving unit configured to reserve transmission of the data having the electronic signature generated by the signature generation unit; and

a restriction unit configured to, when the transmission of the data having the generated electronic signature is reserved by the transmission reserving unit, restrict deletion of the generation information of the electronic signature added to the reserved data.

2. The apparatus according to claim 1, wherein the transmission reserving unit configured to reserve the transmission so that the data having the electronic signature generated by the signature generation unit is transmitted at a designated time.

3. A communication apparatus having a function of transmitting data at a designated time, comprising:

a storage unit configured to store generation information to be used for generating an electronic signature;

a signature generation unit configured to generate an electronic signature by using the generation information;

a transmission reserving unit configured to reserve a transmission so that the data having the electronic signature generated by the signature generation unit is transmitted at a designated time;

a determination unit configured to determine whether the designated time is within a valid time of the generation information; and

an notification unit configured to notify a user of a warning when the determination unit determines that the designated time is not within the valid time.

4. The apparatus according to claim 3, further comprising a warning display unit configured to display a warning when the determination unit determines that the designated time is not within the valid time of the generation information.

5. The apparatus according to claim 3, wherein the generation information is an electronic certificate.

6. The apparatus according to claim 5, further comprising an update unit configured to update the electronic certificate when the determination unit determines that the designated time is not within the valid time.

7. The apparatus according to claim 6, wherein the update unit comprises:

a generation unit configured to generate issuing request information to request issue of the electronic certificate;

a transmission unit configured to transmit the issuing request information generated by the generation unit to a certificate authority that issues an electronic certificate; and

an acquisition unit configured to acquire the electronic certificate issued by the certificate authority in response to the issuing request information.

8. A control method of a communication apparatus having a function of transmitting data at a designated time, comprising:

generating an electronic signature by using generation information being stored in a memory and to be used for generating an electronic signature;

deleting the generation information;

reserving transmission of the data having the generated electronic signature; and

restricting deletion of the generation information of the electronic signature added to the reserved data when the transmission of the data having the generated electronic signature is reserved.

9. The method according to claim 8, wherein the reserved transmission of the data having the generated electronic signature is transmitted at a designated time.

10. A control method of a communication apparatus having a function of transmitting data at a designated time, comprising:

generating an electronic signature by using generation being stored in a memory and to be used for generating an electronic signature;

reserving a transmission so that the data having the generated electronic signature is transmitted at a designated time;

determining whether the designated time is within a valid time of the generation information; and

notifying a user of a warning when it is determined that the designated time is not within the valid time.

11. The method according to claim 10, further comprising displaying a warning when it is determined that the designated time is not within the valid time.

12. The method according to claim 10, wherein the generation information is an electronic certificate.

13. The method according to claim 12, further comprising updating the electronic certificate when it is determined that the designated time is not within the valid time.

14. The method according to claim 13, further comprising:

generating issuing request information to request issue of the electronic certificate;

transmitting the generated issuing request information to a certificate authority that issues an electronic certificate; and

acquiring the electronic certificate issued by the certificate authority in response to the issuing request information.

15. A computer readable medium storing a program for controlling a communication apparatus having a function of transmitting data at a designated time, the program comprising:

a code to generate an electronic signature by using generation information being stored in a memory and to be used for generating an electronic signature;

a code to delete the generation information;

a code to reserve transmission of the data having the generated electronic signature; and

a code to restrict deletion of the generation information of the electronic signature added to the reserved data when the transmission of the data having the generated electronic signature is reserved.

16. The computer readable medium according to claim 15, wherein the reserved transmission of the data having the generated electronic signature is transmitted at a designated time.

17. A computer readable medium storing a program for controlling a communication apparatus having a function of transmitting data at a designated time, the program comprising:

a code to generate an electronic signature by using generation being stored in a memory and to be used for generating an electronic signature;

a code to reserve a transmission so that the data having the generated electronic signature is transmitted at a designated time;

a code to determine whether the designated time is within a valid time of the generation information; and

a code to notify a user of a warning when it is determined that the designated time is not within the valid time.

18. The computer readable medium according to claim 17, wherein the program further comprises

a code to display a warning when it is determined that the designated time is not within the valid time.

19. The computer readable medium according to claim 17, wherein the generation information is an electronic certificate.

20. The computer readable medium according to claim 19, wherein the program further comprises

a code to update the electronic certificate when it is determined that the designated time is not within the valid time.

21. The computer readable medium according to claim 20, wherein the program further comprises:

a code to generate issuing request information to request issue of the electronic certificate;

a code to transmit the generated issuing request information to a certificate authority that issues an electronic certificate; and

a code to acquire the electronic certificate issued by the certificate authority in response to the issuing request information.