Improvement of Communication Traffic and Security of Proactive Secret Sharing Schemes and Combination Proactive Secret Sharing Scheme with an Asymmetric Secret Sharing Scheme

Abstract

An asymmetric secret sharing scheme (A-SSS) can set the number of data servers that hold shares to less than k because it can generate up to k – 1 shares from one key of the secret's owner. Therefore, the secret is not revealed even if all the data servers are attacked. However, if the owner's key is stolen and attacked, the secret may be leaked. Therefore, in this paper, we propose two proactive secret sharing schemes (P-SSSs) suitable for an A-SSS and show that they can substantially reduce communication in comparison with a conventional P-SSS. In addition, we propose an improvement of the conventional P-SSS that raises security.