We study the problem of non-interactive multiparty computation (NI-MPC) where a group of completely asynchronous parties can evaluate a function over their joint inputs by sending a single message to an evaluator who computes the output. Previously, the only general solutions to this problem that resisted collusions between the evaluator and a set of parties were based on multi-input functional encryption and required the use of complex correlated randomness setup. In this work, we present a new solution for NI-MPC against arbitrary collusions using a public-key infrastructure (PKI) setup supplemented with a common random string. A PKI is, in fact, the minimal setup that one can hope for in this model in order to achieve a meaningful “best possible” notion of security, namely, that an adversary that corrupts the evaluator and an arbitrary set of parties only learns the residual function obtained by restricting the function to the inputs of the uncorrupted parties. Our solution is based on indistinguishability obfuscation and DDH both with sub-exponential security. We extend this main result to the case of general interaction patterns, providing the above best possible security that is achievable for the given interaction. Our main result gives rise to a novel notion of (public-key) multiparty obfuscation, where n parties can independently obfuscate program modules Mi such that the obfuscated modules, when put together, exhibit the functionality of the program obtained by “combining” the underlying modules Mi. This notion may be of independent interest.
|Title of host publication
|Advances in Cryptology – ASIACRYPT 2017 - 23rd International Conference on the Theory and Applications of Cryptology and Information Security, Proceedings
|Tsuyoshi Takagi, Thomas Peyrin
|Number of pages
|Published - 2017
|23rd Annual International Conference on Theory and Application of Cryptology and Information Security, ASIACRYPT 2017 - Hong Kong, Hong Kong
Duration: 3 Dec 2017 → 7 Dec 2017
|Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
|23rd Annual International Conference on Theory and Application of Cryptology and Information Security, ASIACRYPT 2017
|3/12/17 → 7/12/17
Bibliographical notePublisher Copyright:
© International Association for Cryptologic Research 2017.