Patent ID: 8964988
Filing Date: 2015-02-24
Classification: H04L

Abstract:
1. A secret sharing system, comprising: a sharing apparatus; Σ an acquisition apparatus, wherein the sharing apparatus includes: a secret sharing unit that independently shares a value corresponding to each element θ(ψ, i, β)·g each of the share management apparatuses PA(α, h(α)) includes: a share secret value generation unit that receives the share information SH(ψ, i, β, α, h(α)) corresponding to the share management apparatuses PA(α, h(α)), and generates share secret values DSH(ψ, α, h(α)) corresponding to the share management apparatuses PA(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)), where h(α)=1, . . . , H(α), and the acquisition apparatus includes: a reconstruction unit that generates reconstructed secret values SUBSK(ψ, α) for each subset SUB(α) from a plurality of the share secret values DSH(ψ, α, h(α)) for the subset SUB(α) by performing reconstruction processing for the subset SUB(α) according to the secret sharing scheme; and a synthesis unit that generates generation information D*(ψ) from the reconstructed secret values SUBSK(ψ, α).