Introducing leanSig: A Hash-Based Signature Library for Ethereum
ConsensusSignaturesRelease
We are releasing leanSig, a Rust implementation of XMSS-based signatures designed specifically for Ethereum’s consensus layer.
Why hash-based signatures?
Hash-based signature schemes like XMSS are among the most conservative post-quantum options available. Their security relies only on the collision resistance of hash functions — a well-understood property with decades of cryptanalytic scrutiny.
What leanSig provides
leanSig is a minimal, auditable Rust library that implements XMSS with parameters tuned for Ethereum’s consensus requirements. It prioritizes correctness and verifiability over feature breadth.
The library is currently being tested across approximately ten client teams building post-quantum consensus clients using the leanSpec executable specification.
Next steps
- Continued multi-client interoperability testing
- Performance benchmarking under realistic validator loads
- Integration with leanMultisig for SNARK-based aggregation