Zero Knowledge lean Ethereum Part 4: leanVM, a Custom VM for Signature Aggregation
Mar 11, 2026
Thomas Coratger, researcher and post-quantum team lead at the Ethereum Foundation, discusses LeanVM, a minimal zkVM built for signature aggregation. They explain why a VM was chosen over fixed circuits, the tiny 4-opcode design inspired by Cairo, and implementation choices like Plonky3 and WHIR for CPU-friendly proving. Benchmarks, recursion tradeoffs, and how the project invites community contributions are also covered.
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LeanVM Deliberately Keeps The ISA Tiny
- LeanVM targets extreme minimalism: four opcodes and two precompiles to reduce code surface and ease formal verification.
- Emil compared it to Cairo but even simpler, removing the AP register to limit complexity for enshrinement.
Simplicity Trumps Fancy Prover Tricks For Recursion
- Simpler proving primitives beat many ad-hoc speed tricks when recursion is required for security and verifiability.
- Emil noted fancy prover optimizations add complexity that makes recursion slower and formal reasoning harder.
How To Contribute To Lean Ethereum Work
- Follow and contribute via the Lean Ethereum GitHub org, Telegram PQ channel, and weekly post-quantum calls.
- Thomas Coratger invited contributors to work on leanSig, lean multisig, Plonky3, and WHIR optimizations.