One-Time Tables for Two-Party Computation

In two-party secure computation, a pair of mutually-distrusting and potentially malicious parties attempt to evaluate a function f(x, y) of private inputs x and y, held respectively by each, without revealing anything but f(x, y) and without involving a trusted third party. This goal has been achieved with varying degrees of generality and effciency using a variety of primitives, including combined oblivious transfer (OT) [GMW87], abstract oblivious transfer [K88], and committed oblivious transfer [CTG95]. This work introduces the concept of a two-party one-time table (OTT), a novel primitive that is theoretically equivalent to precomputed OT. The OTT is tailored to support field computations rather than single-bit logical operations, thereby streamlining higher-level computations, particularly where information-theoretic security is demanded. The two-party one-time table is also motivated by the ease with which it can be constructed using simple resources provided by one or more partly-trusted external servers. This commodity-based approach strengthens overall security by ensuring that information flows strictly from servers to Alice and Bob, removing the need to trust third parties with the sensitive data itself.