COMMUNICATION APPARATUS, CONTROL METHOD, AND STORAGE MEDIUM

• US 20130297938A1
• Filed: 04/09/2013
• Published: 11/07/2013
• Est. Priority Date: 05/01/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Goto, Fumihide
• Granted Patent: US 9,843,444 B2
• Time in Patent Office: Days
• US Class Current: 713/171
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Disclosed is a communication apparatus for executing processing for sharing an encryption key between itself and another party'"'"'s communication apparatus, wherein the communication apparatus executes the processing, respectively at least one time, as an authenticating apparatus and an authenticated apparatus. The communication apparatus determines which encryption key of an encryption key provided by this communication apparatus and an encryption key provided by the other party'"'"'s communication apparatus is the encryption key used in common by this communication apparatus and the other party'"'"'s communication apparatus, and decides, in accordance with result of the determination, which of this communication apparatus and the other party'"'"'s communication apparatus is to be made the authenticating apparatus first.

Claims

1. A communication apparatus for executing processing for sharing an encryption key between itself and another party'"'"'s communication apparatus, wherein the communication apparatus executes the processing, respectively at least one time, as an authenticating apparatus and an authenticated apparatus, the communication apparatus comprising:

a determination unit configured to determine which encryption key of an encryption key provided by the communication apparatus and an encryption key provided by the other party'"'"'s communication apparatus is the encryption key used in common by the communication apparatus and the other party'"'"'s communication apparatus; and

a decision unit configured to decide, in accordance with result of the determination, which of the communication apparatus and other party'"'"'s communication apparatus is to be made the authenticating apparatus first.

2. The apparatus according to claim 1, wherein said decision unit decides that an apparatus that does not provide the encryption key used in common for encryption by the communication apparatus and the other party'"'"'s communication apparatus is to be made the authenticating apparatus first.

3. The apparatus according to claim 1, wherein said decision unit decides which of the communication apparatus and other party'"'"'s communication apparatus is to be made the authenticating apparatus first based upon address information of the communication apparatus and address information of the other party'"'"'s communication apparatus.

4. The apparatus according to claim 1, wherein said determination unit compares MAC addresses of the communication apparatus and of the other party'"'"'s communication apparatus and determines that the encryption key provided by the communication apparatus having the smaller MAC address is the encryption key used in common for encryption by the communication apparatus and the other party'"'"'s communication apparatus.

5. The apparatus according to claim 1, further comprising a sharing unit configured to execute processing for sharing an encryption key.

6. The apparatus according to claim 5, wherein said sharing unit executes processing for sharing a unicast key.

7. The apparatus according to claim 5, wherein said sharing unit executes processing for sharing a group key.

8. The apparatus according to claim 5, wherein said sharing unit executes processing for sharing an encryption key by wireless communication.

9. The apparatus according to claim 1, further comprising an error determination unit configured to determine an error in the processing for sharing an encryption key;

wherein encrypted communication using an encryption key shared by previous processing for sharing an encryption key is performed in accordance with the determination made by said error determination unit.

10. The apparatus according to claim 1, wherein in accordance with the determination made by said determination unit, processing for sharing an encryption key is executed using an encryption key shared by previous processing for sharing an encryption key.

19. A non-transitory computer-readable storage medium storing a computer program for causing a computer to function as each of the units possessed by the communication apparatus set forth in claim 1.

11. A communication apparatus for executing processing for sharing an encryption key between itself and another party'"'"'s communication apparatus, wherein the communication apparatus executes the processing, respectively at least one time, as an authenticating apparatus and an authenticated apparatus, the communication apparatus comprising:

a determination unit configured to determine, after the communication apparatus serving as either the authenticating apparatus or the authenticated apparatus has executed the processing for sharing the encryption key, whether an error has occurred in separate processing for sharing the encryption key; and

an execution unit configured to perform, in a case where said determination unit has determined occurrence of an error, and using an encryption key used in common for encryption by the communication apparatus and the other party'"'"'s communication apparatus, at least either of decryption of a signal, which relates to the processing for sharing the encryption key received from the other party'"'"'s communication apparatus, and encryption of a signal, which relates to the processing for sharing the encryption key transmitted to the other party'"'"'s communication apparatus, and to execute the processing for sharing the encryption key.

12. The apparatus according to claim 11, wherein the error is at least one of a timeout error, which is ascribable to timing out of a predetermined timer after the start of, and before the end of, a single execution of processing for sharing the encryption key, and a retry error, which is ascribable to retransmission of a signal by the communication apparatus a predetermined number of times.

20. A non-transitory computer-readable storage medium storing a computer program for causing a computer to function as each of the units possessed by the communication apparatus set forth in claim 11.

13. A control method in a communication apparatus for executing processing for sharing an encryption key between itself and another party'"'"'s communication apparatus, wherein the communication apparatus executes the processing, respectively at least one time, respectively at least one time, as an authenticating apparatus and an authenticated apparatus, the method comprising:

determining which encryption key of an encryption key provided by the communication apparatus and an encryption key provided by the other party'"'"'s communication apparatus is the encryption key used in common by the communication apparatus and the other party'"'"'s communication apparatus; and

deciding, in accordance with result of the determination, which of the communication apparatus and other party'"'"'s communication apparatus is to be made the authenticating apparatus first.

14. The method according to claim 13, wherein in the decision, it is decided that an apparatus that does not provide the encryption key used in common for encryption by the communication apparatus and the other party'"'"'s communication apparatus is to be made the authenticating apparatus first.

15. The method according to claim 13, wherein in the decision, it is decided, based upon address information of the communication apparatus and address information of the other party'"'"'s communication apparatus, which of the communication apparatus and other party'"'"'s communication apparatus is to be made the authenticating apparatus first.

16. The method according to claim 13, wherein in the determination, MAC addresses of the communication apparatus and of the other party'"'"'s communication apparatus are compared and it is determined that the encryption key provided by the communication apparatus having the smaller MAC address is the encryption key used in common for encryption by the communication apparatus and the other party'"'"'s communication apparatus.

17. The method according to claim 13, further comprising determining an error in the processing for sharing an encryption key;

wherein encrypted communication using an encryption key shared by previous processing for sharing an encryption key is performed in accordance with the determination of the error.

18. A control method in a communication apparatus for executing processing for sharing an encryption key between itself and another party'"'"'s communication apparatus, wherein the communication apparatus executes the processing, respectively at least one time, as an authenticating apparatus and an authenticated apparatus, the method comprising:

determining, after the communication apparatus serving as either the authenticating apparatus or the authenticated apparatus has executed the processing for sharing the encryption key, whether an error has occurred after the start of, and before completion of, separate processing for sharing the encryption key; and

performing, in a case where occurrence of the error has been determined, by using an encryption key used in common for encryption by the communication apparatus and the other party'"'"'s communication apparatus, at least either of decryption of a signal, which relates to the processing for sharing the encryption key received from the other party'"'"'s communication apparatus, and encryption of a signal, which relates to the processing for sharing the encryption key transmitted to the other party'"'"'s communication apparatus, and executing the processing for sharing the encryption key.