Communication apparatus, digital signature issuance method and apparatus, and digital signature transmission method

• US 20050160273A1
• Filed: 01/21/2005
• Published: 07/21/2005
• Est. Priority Date: 01/21/2004
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Oishi, Kazuomi
• Granted Patent: US 8,392,716 B2
• Time in Patent Office: Days
• US Class Current: 713/180
• CPC Class Codes: H04L 2209/76 Proxy, i.e. using intermediary entity to perform cryptographic operations
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/123 received data contents, e.g. message integrity
• CPC Class Codes: H04L 9/0841 involving Diffie-Hellman or related key agreement protocols
• 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

An initiator shares y_ir with a responder, calculates HASH_I on the basis of y_ir, and sends HASH_I to an IKE proxy server. The initiator receives a digital signature SIG_S generated for HASH_I and the address of the initiator from the IKE proxy server and sends the digital signature SIG_S to the responder.

Claims

1. A communication apparatus comprising:

generation means for generating data; and

communication means for sending the generated data to a digital signature issuance apparatus,

wherein said communication means receives a digital signature issued by the digital signature issuance apparatus for the generated data and an address used by said communication means and sends the issued digital signature to a communication partner.

2. The apparatus according to claim 1, wherein

said generation means generates a key and the data on the basis of data exchanged with the communication partner for key generation, and said communication means encrypts the issued digital signature using the key and sends the digital signature to the communication partner.

3. A digital signature issuance method comprising steps of:

executing server-aided computation to share secret data for encryption in response to a request from an apparatus; and

generating a digital signature for data generated by the apparatus and an address used by the apparatus and issuing the digital signature to the apparatus.

4. The method according to claim 3, wherein

in the execution step, while monitoring an IP address used by an apparatus executing IKE (Internet Key Exchange), server-aided computation of a Diffie-Hellman public-key distribution scheme in IKE is executed in response to a request from the apparatus.

5. The method according to claim 3, wherein

in the issuance step, a digital signature is generated for a hash value generated by the apparatus and the IP address used by the apparatus and is issued to the apparatus.

6. The method according to claim 3, wherein

in the issuance step, a public-key certificate containing an IP address used by an apparatus having a public key and private key, the public key, and information defining that the apparatus is a signature generation apparatus is supplied to the apparatus which executes IKE.

7. The method according to claim 3, wherein

the method is executed on a default gateway of the apparatus.

11. A public-key certificate which includes, as contents of the certificate, an IP address used by an apparatus having a public key and private key, and the public key, further including information defining that the apparatus is a signature generation apparatus in a digital signature issuance method defined in claim 3.

8. A digital signature issuance method comprising steps of:

receiving data from a second apparatus which executes cryptographic communication with a first apparatus;

generating, using a private key, a digital signature for the received data and an address used by the second apparatus; and

sending a certificate of a public key corresponding to the private key and the generated digital signature to the second apparatus.

9. A digital signature issuance apparatus which issues a digital signature to a second apparatus that executes cryptographic communication with a first apparatus, comprising

communication means for communicating with the second apparatus;

and

generation means for generating a digital signature for data received from the second apparatus and an address used by the second apparatus, using a private key,

wherein said communication means sends a certificate of a public key corresponding to the private key, and the generated digital signature to the second apparatus.

10. A transmission method for a communication apparatus to send a digital signature to a communication partner, comprising

sharing secret data with the communication partner;

calculating a hash value on the basis of the secret data;

sending the hash value to a digital signature issuance apparatus;

receiving a digital signature generated for the hash value and an address of the communication apparatus from the digital signature issuance apparatus; and

sending the digital signature to the communication partner.

12. A digital signature issuance program comprising steps of:

executing server-aided computation to share secret data for encryption in response to a request from an apparatus; and

generating a digital signature for data generated by the apparatus and an address used by the apparatus and issuing the digital signature to the apparatus.

13. A digital signature issuance program comprising steps of:

receiving data from a second apparatus which executes cryptographic communication with a first apparatus;

generating, using a private key, a digital signature for the received data and an address used by the second apparatus; and

sending a certificate of a public key corresponding to the private key and the generated digital signature to the second apparatus.

14. A transmission program for a communication apparatus to send a digital signature of a communication partner, comprising

sharing secret data with the communication partner;

calculating a hash value on the basis of the secret data;

sending the hash value to a digital signature issuance apparatus;

receiving a digital signature generated for the hash value and an address of the communication apparatus from the digital signature issuance apparatus; and

sending the digital signature to the communication partner.