Non-interactive Zero-Sharing with Applications to Private Distributed Decision Making

We employ the new primitive of non-interactive zero-sharing to realize efficiently and privately various “distributed decision making” procedures. Our methodology emphasizes non-interactiveness and universal verifiability. Non-interactiveness suggests that there is no need for bilateral communication between the active participants; instead decision making is achieved by unilateral communication between active participants and a non-trusted server that participates in the protocol. Universal verifiability, in our setting, suggests that the participants’ actions produce a public audit trail that ensures to the public that they are following the specifications of the protocol. Based on non-interactive zero-sharing, we present concrete constructions for a private veto protocol, a protocol for simultaneous disclosure of information, and a privacyenhancing “plug-in” tool for electronic voting that can be incorporated in homomorphic-encryption based schemes.