Round Optimal Secure Multiparty Computation from Minimal Assumptions

Cryptography has been traditionally viewed as a mechanism that enables secure communication between a set of parties. Early research in cryptography has led to the development of novel primitives such as encryption and digital signatures that have allowed parties to communicate data without compromising both the confidentiality and the integrity of the data. However, a drawback of these primitives is that they can only act on data at rest. This roughly means that once we encrypt or digitally sign some data, we can no longer perform any computation on the data and the data becomes immutable. Today, with the advent of cloud computing, it is not sufficient to only have data at rest, and in fact, we need the ability to compute on data while maintaining the confidentiality and the integrity. This is what is enabled by Secure Multiparty Computation.Secure multiparty computation (MPC) allows a set of parties to compute a function on their private inputs such that the parties only learn the output of the function and everything else about their inputs is hidden. This notion was introduced in the seminal works of Yao [Yao82; Yao86] and Goldreich, Micali and Wigderson [GMW87] and has served as a cornerstone of modern cryptography. Over the last thirty years, this field as seen tremendous progress in the theoretic constructions of secure protocols as well as constructing concretely efficient protocols for practical purposes. Moreover, tools and techniques developed in this area have helped resolve several long standing open problems in other areas of cryptography and complexity theory. In spite of this phenomenal progress, several fundamental questions …