Universally Composable Oblivious Transfer in the Multi-party Setting

We construct efficient universally composable oblivious transfer protocols in the multi-party setting for honest majorities. Unlike previous proposals our protocols are designed in the plain model (i.e., without a common reference string), are secure against malicious adversaries from scratch (i.e., without requiring an expensive compiler), and are based on weaker cryptographic assumptions than comparable twoparty protocols. Hence, the active participation of auxiliary parties pays off in terms of complexity. This is particularly true for the construction of one of our building blocks, an efficient universally composable homomorphic commitment scheme. Efficient solutions for this problem in the two-party setting are not known, not even in the common reference string model.

• Type: Conference
• Year: 2006
• Where: CTRSA
• Authors: Marc Fischlin
• Keywords: Common Reference String, Comparable Twoparty Protocols, Composable Oblivious Transfer, Cryptology, CTRSA 2006