(1) We construct secure Two-Party Computation (2PC) protocols for general functionalities with optimal round complexity and computational assumptions using stateless tokens. More precisely, we show how to realize arbitrary functionalities with GUC security in two rounds under the minimal assumption of One-Way Functions (OWFs). Moreover, our construction relies on the underlying function in a black-box way. As a corollary, we obtain feasibility of Multi-Party Computation (MPC) with GUC-security under the minimal assumption of OWFs. As an independent contribution, we identify an issue with a claim in a previous work by Goyal, Ishai, Sahai, Venkatesan and Wadia in TCC 2010 regarding the feasibility of UC-secure computation with stateless tokens assuming collision-resistant hash-functions (and the extension based only on one-way functions).
(2) We then construct a 3-round MPC protocol to securely realize arbitrary functionalities with GUC-security starting from any semi-honest secure MPC protocol. For this construction, we require the so-called one-many commit-and-prove primitive introduced in the original work of Canetti, Lindell, Ostrovsky and Sahai in STOC 2002 that is round-efficient and black-box in the underlying commitment. Using specially designed ``input-delayed'' protocols we realize this primitive (with a 3-round protocol in our framework) using stateless tokens and one-way functions (where the underlying one-way function is used in a black-box way).Category / Keywords: Secure Computation, Tamper-Proof Hardware, Round Complexity, Minimal Assumptions Original Publication (with minor differences): IACR-TCC-2016 Date: received 13 Sep 2015, last revised 1 Sep 2016 Contact author: carmit hazay at biu ac il Available format(s): PDF | BibTeX Citation Note: The related work section has been updated. Version: 20160901:135023 (All versions of this report) Short URL: ia.cr/2015/887 Discussion forum: Show discussion | Start new discussion