Communication apparatus, control method thereof and computer readable medium

• US 7,987,375 B2
• Filed: 11/05/2007
• Issued: 07/26/2011
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ogasawara, Taku, Yamauchi, Hisayuki
• Primary Examiner(s): Zand; Kambiz
• Assistant Examiner(s): Wyszynski; Aubrey H
• Application Number:
  US11/934,857
• Publication Number:
  US 20080120506A1
• Time in Patent Office: 1,359 Days
• Field of Search: 713/193, 713/176
• US Class Current: 713/193
• 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 using the generation information;

a transmission reserving unit configured to reserve transmission of data to which the electronic signature generated by the signature generation unit is to be added;

a receiving unit configured to receive from a user a request for deleting the generation information; and

a delete unit configured to delete, in a case where the receiving unit receives the request for deleting the generation information and the transmission of the data to which the electronic signature is to be added is not reserved by the transmission reserving unit, the generation information,

wherein the delete unit, in a case where the receiving unit receives the request for deleting the generation information and the transmission of the data to which the electronic signature is to be added is reserved by the transmission reserving unit, does not delete the generation information to be used for generating the electronic signature.

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

7. The apparatus according to claim 1, wherein

said delete unit, in a case where the receiving unit receives the request for deleting the generation information and the transmission of the data to which the electronic signature is to be added is reserved by the transmission reserving unit, notifies a user of an error message without deleting the generation information to be used for generating the electronic signature.

8. The apparatus according to claim 2, further comprising a designating unit configured to designate the time of the transmission of the data in accordance with an instruction from a user.

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

reserving transmission of data to which generated electronic signature is to be added, the generated electronic signature being generated by using generation information, the generation information being stored in a memory and to be used for generating the electronic signature

receiving a request for deleting the generation information from a user; and

deleting, in a case where the request for deleting the generation information is received and the transmission of the data to which the electronic signature is to be added is not reserved, the generation information,

wherein, in a case where the request for deleting the generation information is received and the transmission of the data to which the electronic signature is to be added is reserved,

the generation information to be used for generating the electronic signature is not deleted.

4. The method according to claim 3, wherein the data for which transmission is reserved and having the generated electronic signature is transmitted at a designated time.

5. A non-transitory 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 data to which the generated electronic signature is to be added;

a code to receive a request from a user for deleting the generation information; and

a code to delete, in a case where the request for deleting the generation information is received and the transmission of the data to which the electronic signature is to be added is not reserved, the generation information,

wherein, in a case where the request for deleting the generation information is received and the transmission of the data to which the electronic signature is to be added is reserved, the generation information to be used for generating the electronic signature is not deleted.

6. The non-transitory computer readable medium according to claim 5, wherein the data to which the generated electronic signature is to be added is transmitted at a designated time.