Robust Multiparty Computation with Linear Communication Complexity

We present a robust multiparty computation protocol. The protocol is for the cryptographic model with open channels and a polytime adversary, and allows n parties to actively securely evaluate any poly-sized circuit with resilience t < n/2. The total communication complexity in bits over the point-to-point channels is O(Snκ + nBC), where S is the size of the circuit being securely evaluated, κ is the security parameter and BC is the communication complexity of one broadcast of a κ-bit value. This means the average number of bits sent and received by a single party is O(Sκ+BC), which is almost independent of the number of participating parties. This is the first robust multiparty computation protocol with this property.