Paper 2026/2157

Jolt-QED: Formally Verifying Bytecode Expansions In Lean

Ari Biswas, University of Warwick, Layer Zero Labs
Quang Dao, Carnegie Mellon University, Layer Zero Labs
Daniel Ross, Independent Researcher
Justin Thaler, Georgetown University, A16z Crypto
Abstract

In this work, we verify, using the Lean 4 proof assistant, that the Jolt zk-VM's expanded programs faithfully emulate a RISC-V CPU. Prior work translated the official Sail specification of RISC-V into Lean. We extend this model to define the Jolt ISA in Lean. We build a generator that runs Jolt's Rust bytecode expander and renders its output as Lean programs. Finally, for 51 out of 58 such programs, we prove these expansions are equivalent to their corresponding RISC-V instructions. This lays the groundwork for proving completeness and soundness of further stages of Jolt's proving pipeline.

Metadata
Available format(s)
PDF
Category
Applications
Publication info
Preprint.
Keywords
formal-verificationleansnarksjolt
Contact author(s)
tcs @ randomwalks xyz
qvd @ andrew cmu edu
daniel_144 @ toastertime net
justin r thaler @ gmail com
History
2026-09-25: revised
2026-09-22: received
See all versions
Short URL
https://ia.cr/2026/2157
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2026/2157,
      author = {Ari Biswas and Quang Dao and Daniel Ross and Justin Thaler},
      title = {Jolt-{QED}: Formally Verifying Bytecode Expansions In Lean},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/2157},
      year = {2026},
      url = {https://eprint.iacr.org/2026/2157}
}
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