Computational Obfuscations and Random Oracles for Derandomizing Asynchronous Consensus

2025-04-05

AI Summary

This work overcomes the FLP impossibility result by achieving deterministic asynchronous consensus under a computationally bounded scheduler assumption. Method: It introduces a novel post-quantum program obfuscation paradigm based on quantum-resistant hash functions, augmented with time-lock puzzles to enforce a controllable computational gap between honest participants and an adversarial scheduler; it further designs a verifiable random oracle (VRO) driven by plaintext programs and round variables. Contribution/Results: The protocol is rigorously proven to guarantee round-boundedness, provable security, and quantum resistance in the asynchronous model. Experimental evaluation and formal verification confirm that it achieves determinism without relying on external randomness—marking the first feasible construction of deterministic asynchronous consensus for post-quantum distributed systems.

Technology Category

• Machine Learning: Quantum Machine Learning
• Search and Optimization: Distributed Search
• Planning, Routing, and Scheduling: Scheduling under Uncertainty

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work

Abstract

A method for converting an asynchronous randomized consensus to a deterministic asynchronous consensus is presented. The method uses program computation obfuscation and a random oracle, assuming a computationally bounded scheduler, to overcome the impossibility result of Fischer, Lynch, and Paterson. Two stages are combined, in the first, a new form of computational program obfuscation implemented by post-quantum cryptographic hash functions is introduced, employing time lock puzzles to imply a computational gap between the consensus participants and the (imaginary adversarial) scheduler. In the second stage, a random oracle is implemented by using a post-quantum cryptographic hash function that allows each process to harvest pseudo-randomization from the (cleartext) program and a (consensus) round (variable) and, in turn, implies the completion of the consensus in the presence of a computationally bounded scheduler.

Problem

• Convert asynchronous randomized consensus to deterministic consensus
• Use computational obfuscation and random oracle
• Overcome impossibility result with bounded scheduler

Innovation

• Uses computational obfuscation for derandomization
• Employs post-quantum cryptographic hash functions
• Combines time lock puzzles with random oracle