A Note on Low-Communication Secure Multiparty Computation via Circuit Depth-Reduction
摘要
We consider the graph-theoretic problem of removing (few) nodes from a directed acyclic graph in order to reduce its depth. While this problem is intractable in the general case, we provide a variety of algorithms in the case where the graph is that of a circuit of fan-in (at most) two, and explore applications of these algorithms to secure multiparty computation with low communication. Over the past few years, a paradigm for low-communication secure multiparty computation has found success based on decomposing a circuit into low-depth “chunks”. This approach was however previously limited to circuits with a “layered” structure. Our graph-theoretic approach extends this paradigm to all circuits. In particular, we obtain the following contributions: We also obtain additional contributions to reducing the amount of bootstrapping for fully homomorphic encryption, and to other types of sublinear-communication MPC protocols such as those based on correlated symmetric private information retrieval.