Attacks to some verifiable multi-secret sharing schemes and two improved schemes

Secret sharing plays an important role in protecting confidential information from being lost, destroyed, or falling into wrong hands. Verifiable multi-secret sharing enables a dealer to share multiple secrets among a group of participants such that the deceptive behaviors of the dealer and the participants can be detected. In this paper, we analyze the security of several recently proposed verifiable multi-secret sharing schemes. We show that these schemes cannot withstand some deceptive behaviors of the dealer, and hence fails to satisfy the basic requirement of secure verifiable secret sharing schemes. After that, we present two improved verifiable multi-secret sharing schemes. Our new schemes can not only resist cheating by the dealer or participants, but also remove the use of private channels.