KEY DISTRIBUTION SYSTEM, TERMINAL DEVICE, KEY DISTRIBUTION METHOD, AND PROGRAM

Title:

KEY DISTRIBUTION SYSTEM, TERMINAL DEVICE, KEY DISTRIBUTION METHOD, AND PROGRAM

Document Type and Number:

WIPO Patent Application WO/2019/198516

Kind Code:

A1

Abstract:

A key distribution system including an N number of terminal devices Ui and a key distribution server used for session key exchanges. The key distribution system has: an isogenic calculation means whereby, if N is an even number, an odd-numbered terminal device Ui uses a base of a first twisted section group having a prescribed elliptical curve and calculates a first public value and an even-numbered terminal device Ui uses a base of a second twisted section group having said elliptical curve and calculates a second public value; a distribution means whereby the key distribution server distributes the first public value calculated by the odd-numbered terminal device Ui to terminal device Ui-1 and terminal device Ui+1 and the distributes the second public value calculated by the even-numbered terminal device Ui to terminal device Ui-1 and terminal device Ui+1; and a key generation means that whereby the odd-numbered terminal device Ui uses the second public value distributed by the distribution means and generates the session key and the even-numbered terminal device Ui uses the first public value distributed by the distribution means and generates the session key. The key distribution system is characterized by the isogenic calculation means calculating the first public value for which a prescribed terminal device UI among the terminal devices Ui uses the first twisted section group base and calculating the second public value using the second twisted section group base, if N is odd.

Inventors:

OKANO YUKI (JP)
YOSHIDA REO (JP)
KOBAYASHI TETSUTARO (JP)

Application Number:

PCT/JP2019/013412

Publication Date:

October 17, 2019

Filing Date:

March 27, 2019

Export Citation:

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Assignee:

NIPPON TELEGRAPH & TELEPHONE (JP)

International Classes:

H04L9/08

Other References:

"Symposium on Cryptography and I n for m a t ion Sec u r i ty", SCIS2016 [USB] SCIS2016, 19 January 2016 (2016-01-19), pages 1 - 8