E-mail information management apparatus, and E-mail information management method

• US 8,832,202 B2
• Filed: 09/10/2008
• Issued: 09/09/2014
• Est. Priority Date: 10/12/2007
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yoshioka, Takashi
• Primary Examiner(s): Georgandellis, Andrew
• Assistant Examiner(s): FORMAN, JAMES Q
• Application Number:
  US12/208,068
• Publication Number:
  US 20090100079A1
• Time in Patent Office: 2,190 Days
• Field of Search: 709/206, 713/176
• US Class Current: 709/206
• CPC Class Codes: G06Q 10/107 Computer-aided management of electronic mailing [e-mailing]
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• 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 E-mail information management apparatus acquires a plurality of predetermined information from a mail header and a mail body and signature related information as signature target information, produces feature variable information and electronic signature data, and stores the signature target information, the variable information and the electronic signature data, as signature header information in a header portion of the E-mail.

Claims

1. A non-transitory computer-readable recording medium storing an E-mail information management program for causing a computer, which manages E-mail information, to execute a process comprising:

acquiring a plurality of predetermined information from a mail header and a mail body, and acquiring, as signature related information, information relating to said plurality of predetermined information, network information of the computer, and a time stamp for signature information, thereby acquiring, as signature target information, said acquired information with attributes thereof made corresponding to respective first attribute tags;

producing feature variable information for said signature target information acquired, and acquiring said feature variable information in a corresponding relation to second attribute tags indicating said feature variable information;

producing a hash value from an entirety of both said signature target information acquired and said feature variable information produced, producing electronic signature data using a secret key of the computer and said hash value, and acquiring said electronic signature data in a corresponding relation to a third attribute tag indicating said electronic signature data;

determining whether or not to produce a fourth attribute tag including an exact copy of said mail body based on whether a size of said mail body exceeds a maximum size threshold specified by policy information;

storing, as signature header information, said signature target information acquired, said feature variable information produced, and said electronic signature data produced in a header portion of E-mail in a corresponding relation to said associated attribute tags;

storing the fourth attribute tag in said header portion of E-mail when the fourth attribute tag including the exact copy of said mail body is produced based on said determining indicating that the size of said mail body does not exceed said maximum size threshold specified by said policy information;

comparing, for each said attribute tag, the stored signature header information with candidate signature information included in the mail header; and

determining whether each attribute of the email has been altered based on a result of said comparing.

2. The recording medium storing said E-mail information management program according to claim 1, wherein when said E-mail is received from another network, storing said signature header information in addition to header information that has already been stored in said header portion of said E-mail in said another network.

3. The recording medium storing said E-mail information management program according to claim 1, wherein said signature related information acquired includes an algorithm, which has been used in applying said electronic signature, together with an attribute tag indicating said algorithm.

4. The recording medium storing said E-mail information management program according to claim 1, wherein said signature related information acquired includes information of a time at which signature information has been produced, together with an attribute tag indicating said time information.

5. The recording medium storing said E-mail information management program according to claim 1, wherein said signature target information acquired is capable of being selectively designated.

6. An E-mail information management apparatus for managing E-mail information, the apparatus comprising:

a computer-readable recording medium which stores a program; and

a computer which executes, based on the program, a process comprising;

acquiring a plurality of predetermined information from a mail header and a mail body, and acquiring, as signature related information, information relating to said plurality of predetermined information, network information, and a time stamp for signature information, thereby acquiring, as signature target information, said acquired information with attributes thereof made corresponding to respective first attribute tags;

producing feature variable information for said signature target information acquired by said acquiring, and acquiring said feature variable information in a corresponding relation to second attribute tags indicating said feature variable information;

producing a hash value from an entirety of both said signature target information and said feature variable information, producing electronic signature data using a secret key value and said hash value, and acquiring said electronic signature data in a corresponding relation to a third attribute tag indicating said electronic signature data;

determining whether or not to produce a fourth attribute tag including an exact copy of said mail body based on whether a size of said mail body exceeds a maximum size threshold specified by policy information;

storing, as signature header information, said signature target information, said feature variable information, and said electronic signature data in a header portion of E-mail in a corresponding relation to said associated attribute tags;

storing the fourth attribute tag in said header portion of E-mail when the fourth attribute tag including the exact copy of said mail body is produced based on said determining indicating that the size of said mail body does not exceed said maximum size threshold specified by said policy information;

comparing, for each said attribute tag, the stored signature header information with candidate signature information included in the mail header; and

determining whether each attribute of the email has been altered based on a result of said comparing.

7. The E-mail information management apparatus according to claim 6, wherein when said E-mail is received from another network, said storing stores said signature header information additionally in said header portion of said E-mail.

8. The E-mail information management apparatus according to claim 6, wherein said signature related information includes an algorithm, which has been used in applying said electronic signature, together with an attribute tag indicating said algorithm.

9. The E-mail information management apparatus according to claim 6, wherein said signature related information includes information of a time at which signature information has been produced, together with an attribute tag indicating said time information.

10. The E-mail information management apparatus according to claim 6, wherein the signature target information is capable of being selectively designated.

11. An E-mail information management method executed by a computer which manages E-mail information, the method comprising:

acquiring a plurality of predetermined information from a mail header and a mail body, and acquiring, as signature related information, information relating to said plurality of predetermined information, network information of the computer, and a time stamp for signature information, thereby acquiring, as signature target information, said acquired information with attributes thereof made corresponding to respective first attribute tags;

producing feature variable information for said signature target information acquired, and acquiring said feature variable information in a corresponding relation to second attribute tags indicating said feature variable information;

producing a hash value from an entirety of both said signature target information acquired and said feature variable information produced, producing electronic signature data using a secret key of the computer and said hash value, and acquiring said electronic signature data in a corresponding relation to a third attribute tag indicating said electronic signature data;

determining whether or not to produce a fourth attribute tag including an exact copy of said mail body based on whether a size of said mail body exceeds a maximum size threshold specified by policy information;

storing, as signature header information, said signature target information acquired, said feature variable information produced, and said electronic signature data produced in a header portion of E-mail in a corresponding relation to said associated attribute tags;

storing the fourth attribute tag in said header portion of E-mail when the fourth attribute tag including the exact copy of said mail body is produced based on said determining indicating that the size of said mail body does not exceed said maximum had size threshold specified by said policy information;

comparing, for each said attribute tag, the stored signature header information with candidate signature information included in the mail header; and

determining whether each attribute of the email has been altered based on a result of said comparing.

12. The E-mail information management method according to claim 11, wherein when said E-mail is received from another network, storing said signature header information in addition to header information that has already been stored in said header portion of said E-mail in said another network.

13. The E-mail information management method according to claim 11, wherein said signature related information acquired includes an algorithm, which has been used in applying said electronic signature, together with an attribute tag indicating said algorithm.

14. The E-mail information management method according to claim 11, wherein said signature related information acquired includes information of a time at which signature information has been produced, together with an attribute tag indicating said time information.

15. The E-mail information management method according to claim 11, wherein said signature target information acquired is capable of being selectively designated.

16. The E-mail information management method according to claim 11, wherein said method further comprises:

when said E-mail is sent to another network and received by said another network, verifying said received E-mail based on said signature header information in said another network.

17. The E-mail information management method according to claim 16, wherein said method comprises:

when said verifying determines that said E-mail is valid, the E-mail information management method is executed in said another network.