Secret sharing system, sharing apparatus, share management apparatus, acquisition apparatus, processing methods thereof, secret sharing method, program, and recording medium

US8549290B2 · kind B2 · utility

Assignee

• NIPPON TELEGRAPH AND TELEPHONE CORPORATION · JP

Inventors

• Ryo Nishimaki · Tokyo, JP
• Koutarou Suzuki · Tokyo, JP

Key dates

• Filing date: Apr 23, 2010
• Grant date: Oct 1, 2013
• Expiry date: Apr 23, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L9/3073
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

A secure secret sharing system is implemented. Shares SH(α, h(α)) are generated by secret sharing of secret information separately for each subset SUB(α); each of share management apparatuses PA(α, h(α)) generates a shared secret value DSH(α, h(α)) by performing a common operation to a corresponding share SH(α, h(α)) and common information containing a common value σ(α) shared in each subset SUB(α); and an acquisition apparatus generates a reconstructed secret value SUBSK(α) by reconstruction processing for each subset SUB(α), using a plurality of shared secret values DSH(α, h(α)) corresponding to the same subset SUB(α), and generates generation information SK by using the reconstructed secret values SUBSK(α).