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

US8964988B2 · kind B2 · utility

Assignee

• NIPPON TELEGRAPH AND TELEPHONE CORPORATION · JP

Inventors

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

Key dates

• Filing date: Jul 22, 2011
• Grant date: Feb 24, 2015
• Expiry date: Dec 3, 2031

Classification

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

Abstract

A sharing apparatus independently shares a value corresponding to each element θ(ψ, i, β)·g2 of basis vectors bi*(θ) among each subset SUB(α) consisting of H(α) share management apparatuses PA(α, 1), . . . , PA(α, H(α)) to generate share information SH(ψ, i, β, α, h(α)) corresponding to each element θ(ψ, i, β)·g2. The share management apparatus PA(α, h(α)) generates a share secret value DSH(ψ, α, h(α)) by performing a common calculation common in the subset SUB(α) on common information shared in the subset SUB(α) and the share information SH(ψ, i, β, α, h(α)). An acquisition apparatus generates reconstructed secret values SUBSK(ψ, α) for each subset SUB(α) by performing a reconstruction processing for the subset SUB(α) and generates generation information D*(ψ) from the reconstructed secret values SUBSK(ψ, α).