Post-Quantum Security Definitions for Relativistic Commitment Protocols

Abstract

Relativistic commitment protocols are a promising candidate for post-quantum information theoretically secure commitments. Unfortunately, the security analysis of these protocols has often been informal. We propose a novel formal framework for proving the security of relativistic bit commitment protocols and use it to prove security for a well established protocol. In addition, we also study an alternative definition of binding for relativistic commitment protocols based on the collapse-binding definition introduced in (Unruh, Eurocrypt 2016).