International Association
for Cryptologic Research

In 1979, Shamir and Blakley introduced secret sharing schemes to provide both security and reliability. In this study, we construct two secret sharing schemes with perfect concealment. The first is an \((n,n)\)-threshold scheme by a group. Although the scheme itself is already known, we prove that its concealment is perfect. We propose the second as a new \((2,n)\)-threshold scheme by a quasigroup.