Verifiable Secret Sharing Scheme Using Hash Values

Abstract

In this paper, we propose a method for secret sharing scheme to identify cheaters and verify reconstructed secret, using hash values calculated following 2×(m + n-k)-regular graph. Our purpose is to solve disadvantages to known previous methods and our contribution is as followings; (i) it can be applied to any secret sharing scheme, and (ii) the size of a share is related only to the number of cheaters that we set, even if the size of secret value increases. As the result, if the number of cheater is less than or equal to the setting number, we can certainly identify a malicious action, and also we can judge whether result of reconstruction is true or false. We conclude that our proposal method is sufficiently practical.