Exploring Non-Interactive Universal Arguments in Cryptography 🔐

Dana Shamir (Tel Aviv University) https://simons.berkeley.edu/talks/dana-shamir-tel-aviv-university-2023-05-01 Minimal Complexity Assumptions for Cryptography In 2002, Barak and Goldreich introduced the notion of a universal argument and constructed an interactive universal argument for non-deterministic computations based on polynomially hard collision-resistant hash functions. Since then, and especially in recent years, there have been tremendous developments in the construction of non-interactive succinct arguments for deterministic computations under standard hardness assumptions. However, the constructed succinct arguments can be proven universal only under sub-exponential assumptions. Assuming polynomially hard fully homomorphic encryption and a widely believed worst-case complexity assumption, we prove a general lifting theorem showing that all existing non-interactive succinct arguments can be made universal. The required complexity assumption is that non-uniformity does not allow arbitrary polynomial speedup. In the setting of uniform adversaries, this extra assumption is not needed.