Title:
MESSAGE TRANSMISSION SYSTEM, COMMUNICATION TERMINAL, SERVER DEVICE, MESSAGE TRANSMISSION METHOD, AND PROGRAM
Document Type and Number:
WIPO Patent Application WO/2018/116826
Kind Code:
A1
Abstract:
The present invention makes it possible to improve confidentiality. A communication terminal stores a session key that is shared with other communication terminals (S3). The communication terminal transmits a pair of a message identifier and an index to a server device where the index is created for a character string associated with a message using the session key (S4). The server device stores the index and message identifier pair (S5). When the session key is updated, the communication terminal creates a re-encryption key using the session key before the update and the session key after the update (S8). The server device uses the re-encryption key to update the stored index to an index created using the updated session key (S9). The communication terminal creates a search query by encrypting a search keyword using the session key (S10). The server device extracts a message identifier with the index matching the search query (S11).
Inventors:
OKANO YUKI (JP)
YOSHIDA REO (JP)
KOBAYASHI TETSUTARO (JP)
YOSHIDA REO (JP)
KOBAYASHI TETSUTARO (JP)
Application Number:
PCT/JP2017/043766
Publication Date:
June 28, 2018
Filing Date:
December 06, 2017
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
International Classes:
G09C1/00; G06F17/30; H04L9/16
Foreign References:
| JP2008084246A | 2008-04-10 |
Other References:
YOSHINO MASAYUKI ET AL.: "Symmetric Searchable Encryption with Key Update Mechanism for Secure Encrypted Database", PROCEEDING OF THE 35TH JOINT CONFERENCE ON MEDICAL INFORMATICS, vol. 35, Suppl., 1 November 2015 (2015-11-01), pages 870 - 873, XP009515430, ISSN: 1347-8508
NTT SOFTWARE, BUSINESS CHAT TOPICROOM, 1 December 2016 (2016-12-01), Retrieved from the Internet
KOBAYASHITETSUTAROYONEYAMAKAZUKIYOSHIDAREOKAWAHARAYUTOFUJIHITOSHI: "Scalable Dynamic Multi-Party Key Distribution Protocol", SCIS2016, 2016, pages 4E2 - 3
W. OGATAK. KOIWAA. KANAOKAS. MATSUO: "Toward Practical Searchable Symmetric Encryption", PROCEEDINGS OF THE ADVANCES IN INFORMATION AND COMPUTER SECURITY, LECTURE NOTES IN COMPUTER SCIENCE, vol. 8231, 2013, pages 151 - 167
KITAKENJITSUDAKAZUHIKOSHISHIBORIMASAMI: "Information Retrieval Algorithm", 2002, KYORITSU SYUPPAN
NTT SOFTWARE, BUSINESS CHAT TOPICROOM, 1 December 2016 (2016-12-01), Retrieved from the Internet
KOBAYASHITETSUTAROYONEYAMAKAZUKIYOSHIDAREOKAWAHARAYUTOFUJIHITOSHI: "Scalable Dynamic Multi-Party Key Distribution Protocol", SCIS2016, 2016, pages 4E2 - 3
W. OGATAK. KOIWAA. KANAOKAS. MATSUO: "Toward Practical Searchable Symmetric Encryption", PROCEEDINGS OF THE ADVANCES IN INFORMATION AND COMPUTER SECURITY, LECTURE NOTES IN COMPUTER SCIENCE, vol. 8231, 2013, pages 151 - 167
KITAKENJITSUDAKAZUHIKOSHISHIBORIMASAMI: "Information Retrieval Algorithm", 2002, KYORITSU SYUPPAN
Attorney, Agent or Firm:
NAKAO, Naoki et al. (JP)
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