Towards Automating Blockchain Consensus Verification with IsabeLLM

2026-01-12

AI Summary

Formal verification of blockchain consensus protocols often relies on costly manual proofs, which are frequently omitted due to their complexity, thereby introducing potential security vulnerabilities. This work proposes IsabeLLM, the first framework integrating a large language model (DeepSeek R1) with the Isabelle/HOL theorem prover to significantly lower the barrier to formal verification and enhance automation through intelligent prompting and automatic proof generation. Using this approach, the authors successfully develop a novel formal model of Bitcoin’s Proof-of-Work consensus protocol and automatically generate correct proofs for all non-trivial lemmas, demonstrating both the feasibility and effectiveness of LLM-assisted formal verification in blockchain systems.

Technology Category

• Machine Learning: Large Multimodal Models (LMMs)
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust
• Knowledge Representation and Reasoning: Automated Reasoning and Theorem Proving

Application Category

• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions
• Economics, Online Markets and Human Computation: Cost models of using LLMs in production systems
• Security and Privacy: Blockchains and distributed ledgers

Abstract

Consensus protocols are crucial for a blockchain system as they are what allow agreement between the system's nodes in a potentially adversarial environment. For this reason, it is paramount to ensure their correct design and implementation to prevent such adversaries from carrying out malicious behaviour. Formal verification allows us to ensure the correctness of such protocols, but requires high levels of effort and expertise to carry out and thus is often omitted in the development process. In this paper, we present IsabeLLM, a tool that integrates the proof assistant Isabelle with a Large Language Model to assist and automate proofs. We demonstrate the effectiveness of IsabeLLM by using it to develop a novel model of Bitcoin's Proof of Work consensus protocol and verify its correctness. We use the DeepSeek R1 API for this demonstration and found that we were able to generate correct proofs for each of the non-trivial lemmas present in the verification.

Problem

• blockchain consensus
• formal verification
• proof automation
• Isabelle
• large language models

Innovation

• formal verification
• blockchain consensus
• Isabelle
• large language model
• proof automation