Episode 394 - leanVM, a Custom VM for Signature Aggregation

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Episode 394. Aired on Mar 11, 2026 See full episode on https://zeroknowledge.fm/podcast/394/ zkMesh+ is live! Subscribe for zkMesh+ and catch the latest State of ZK 2025 report (https://zkmesh.substack.com/subscribe) ----------- In this episode of the lean Ethereum miniseries, Nico Mohnblatt speaks with Thomas Coratger and Emile from the Ethereum Foundation about the design and implementation of LeanVM, a minimal zkVM created to support post-quantum signature aggregation on Ethereum’s consensus layer. They explain why the team chose a VM architecture over fixed circuits and how LeanVM takes inspiration from Cairo with just 4 opcodes and 2 precompiles to keep the instruction set extremely small and make formal verification easier. The conversation also covers LeanVM implementation choices like using Plonky3 and WHIR for efficient proving on CPUs, benchmarks for aggregation speed, and the role of Python specs in testing client interop. They share ongoing efforts to optimize low-level primitives and invite community input on the project. Related Links * zkSummit14 speaker applications close this Sunday March 15! (www.zksummit.com) * lean Ethereum Part 1: Introduction with Justin Drake (https://zeroknowledge.fm/podcast/391/) * lean Ethereum Part 2: PQ Signatures and Poseidon with Dmitry and Benedikt (https://zeroknowledge.fm/podcast/392/) * lean Ethereum Part 3: Security of PQ SNARKs and an update about the Proximity Prize (https://zeroknowledge.fm/podcast/393/) * lean Ethereum (https://blog.ethereum.org/2025/07/31/lean-ethereum) * Lean Consensus R&D Progress (https://leanroadmap.org/) * leanSig Implementation (https://github.com/leanEthereum/leanSig) * Cairo zkVM (https://www.cairo-lang.org/) * WHIR: Reed–Solomon Proximity Testing with Super-Fast Verification (https://eprint.iacr.org/2024/1586.pdf) * Minimal zkVM for Lean Ethereum by Emile (https://github.com/leanEthereum/leanMultisig/blob/main/minimal_zkVM.pdf) ----------- **If you like what we do:** * Find all our links here! @ZeroKnowledge | Linktree (https://linktr.ee/zeroknowledge) * Subscribe to our podcast newsletter (https://zeroknowledge.substack.com) * Follow us on Twitter @zeroknowledgefm (https://twitter.com/zeroknowledgefm) * Join us on Telegram (https://t.me/+taXrPJIp_30zZTNi) * Catch us on YouTube (http://www.youtube.com/channel/UCYWsYz5cKw4wZ9Mpe4kuM_g) **Support the show:** * Patreon (https://www.patreon.com/zeroknowledge) * ETH - Donation address (https://etherscan.io/address/0xE2C080047213C1d8cDf2099E0B07479C5D9cee8a) * BTC - Donation address (https://www.blockchain.com/explorer/addresses/btc/bc1q9mrh34n6mvses59r3hq9dz6j3vxm3tlwlg8ws2) * SOL - Donation address (https://explorer.solana.com/address/Eqfm4maSDUN3ikjDfSgDeJ1mh3iC8tr69eHB5iTHz35x) * ZEC - Donation address (https://mainnet.zcashexplorer.app/address/t1gmdc8jKj4EXfYnNvwkToZUahx78GrQ2zv) 03:36 Why LeanVM Was Chosen 07:50 LeanVM Minimalist Design 08:34 Simplicity Over Speed 19:34 Security and Field Selection 20:41 Performance and Aggregation Benchmarks 28:14 Ethereum Python Specification