UniSphincs
The sphinx asks one question. Will your signature outlive the curve?
Sign a message right now.
SPHINCS- locks a message to your private key. The output is a 944-byte cryptographic seal bound to that exact text. Anyone with the public key can verify the seal. Change a single byte of the message after signing and the seal breaks. Forge a seal without the private key and verification fails.
Type something below, press sign, then tamper the message to watch the seal collapse.
loading…Client-side demo. The seal shown is a deterministic mock derived from your message via WebCrypto SHA-256, believable in size and shape but not the full SPHINCS- engine, which runs server-side or in WASM in production. Real signing produces the same shape. A 944-byte hash bundle that proves you knew the private key without revealing it.
Every Ethereum key breaks the day Q-Day arrives.
Every Ethereum signature today is an ECDSA signature over the secp256k1 curve. When a sufficiently large quantum computer arrives, what NIST calls Q-Day, every secp256k1 key is solvable in minutes. Every wallet exposed. Every contract ownership in question.
The migration to post-quantum signatures is not optional. It is inevitable. The only question is whether the tooling exists by the time it is needed.
SPHINCS-: minimal, stateless, EVM-friendly.
SPHINCS- (SPHINCS minus) is a minimal stateless hash-based post-quantum signature scheme, designed by Vitalik Buterin and optimized for EVM-friendly deployment. The reference implementation lives in the upstream repo as sphincs_minus.py, accompanied by a SphincsMinus.lean formal verification in Lean 4 and a public set of known-answer test vectors.
- No elliptic curves, no pairings, no exotic assumptions.
- Only Ethereum-native hash primitives.
- Python reference plus Lean 4 formal verification.
- Known-answer test vectors included.
See it sign in real time.
We package the work for builders.
We forked SPHINCS- and wrapped it in everything a builder needs to ship. A clean repository. Attribution to the cryptographer who wrote it. A landing page. A browser playground. Forthcoming JavaScript bindings and a Solidity verifier contract for uniswap v4 hook integration.
The sphinx is the keeper at the gate. It knows the riddle before the traveller arrives. We are the keepers behind the keeper. Not the ones who solved the problem, but the ones who carry the answer forward to the builders who need it.
Credit where credit is due.
This repository is a public fork of vbuterin/sphincsminus. Every cryptographic file is the work of Vitalik Buterin and the SPHINCS- paper authors. UniSphincs adds a rebranded README, this landing, full attribution, and a permissive license that applies only to our additions.
If Vitalik Buterin or any of the original authors request changes, we comply immediately. See ATTRIBUTION.md in the repo.
A minimal post-quantum stateless hash-based signature scheme optimized for EVM-friendly deployment.vbuterin/sphincsminus, May 2026
Read the source.
- vbuterin/sphincsminus. Vitalik Buterin's reference implementation in Python and Lean 4.
- github.com/vbuterin. Vitalik's personal GitHub, where SPHINCS- and the wider Ethereum research drafts live.
- SPHINCS-: Efficient Stateless Post-Quantum Signatures. The research paper, included in the upstream repo.
- unisphincs/unisphincs. This fork.
- NIST Post-Quantum Cryptography Programme. The broader context for the migration.