---
title: "Schnorr signatures on secp256k1: which blockchains use it"
url: "https://hardyindex.com/algorithms/schnorr-secp256k1"
---

# Schnorr signatures on secp256k1

Schnorr signatures over the secp256k1 curve. Bitcoin's form is specified in BIP-340 and used by Taproot; Bitcoin Cash adopted its own Schnorr variant in 2019. Broken by Shor's algorithm on a cryptographically relevant quantum computer, which recovers the private key from the public key.

- **Quantum status:** Broken by Shor's algorithm on a cryptographically relevant quantum computer.
- **Standard:** BIP-340 (BIP, final).
- **Family:** elliptic curve.
- **Also known as:** BIP-340, Schnorr.

## Rated chains using it

- [Bitcoin](https://hardyindex.com/chains/bitcoin.md): account signatures, mainnet, default, BIP-340. Taproot outputs. Source (specification or proposal): https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki
- [Bitcoin Cash](https://hardyindex.com/chains/bitcoin-cash.md): account signatures, mainnet, default. Bitcoin Cash Schnorr, adopted in 2019; not BIP-340. Source (statement or write-up): https://blog.bitjson.com/quantumroot/
- [Decred](https://hardyindex.com/chains/decred.md): account signatures, mainnet, opt-in, EC-Schnorr-DCRv0. Signature type 2, Decred's own Schnorr variant rather than BIP-340, verified by OP_CHECKSIGALT. Treasury spends must carry an EC-Schnorr-DCRv0 signature from one of the Politeia keys in the chain parameters (DCP-0006). Source (source code or release): https://github.com/decred/dcrd/blob/master/txscript/stdscript/scriptv0.go
- [eCash](https://hardyindex.com/chains/ecash.md): account signatures, mainnet, default. The Schnorr variant activated in May 2019, before the split from Bitcoin Cash; not BIP-340. Source (specification or proposal): https://github.com/Bitcoin-ABC/bitcoin-abc/blob/master/doc/standards/schnorr.md
- [eCash](https://hardyindex.com/chains/ecash.md): validator consensus, mainnet, mandatory. Avalanche proofs sign each stake with the staked coin's key, and delegations and poll responses carry 64-byte Schnorr signatures. Avalanche finalises blocks and, since November 2025, transactions. Source (specification or proposal): https://github.com/Bitcoin-ABC/bitcoin-abc/blob/master/doc/avalanche.md
- [Internet Computer](https://hardyindex.com/chains/internet-computer.md): threshold signing, mainnet, opt-in, BIP-340. Chain-key signatures. Source (specification or proposal): https://docs.internetcomputer.org/concepts/chain-key-cryptography/
- [Kaspa](https://hardyindex.com/chains/kaspa.md): account signatures, mainnet, default, 32-byte x-coordinate keys. Address version 0 (PubKey). Source (source code or release): https://github.com/kaspanet/rusty-kaspa/blob/master/crypto/addresses/src/lib.rs
- [Midnight](https://hardyindex.com/chains/midnight.md): account signatures, mainnet, default, BIP-340. Authorises unshielded UTXO spends on Midnight's ledger. Shielded spends use a zero-knowledge proof instead, and NIGHT held on Cardano as cNIGHT is under Cardano's Ed25519 keys. Source (specification or proposal): https://github.com/midnightntwrk/midnight-ledger/blob/main/spec/preliminaries.md
- [Qtum](https://hardyindex.com/chains/qtum.md): account signatures, mainnet, opt-in. BIP-340 Schnorr for Taproot outputs, which the node verifies on every block; added in the v22.0 hard fork. Source (source code or release): https://github.com/qtumproject/qtum/blob/master/src/validation.cpp

## Sources

- [BIP-340: Schnorr Signatures for secp256k1](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki), Bitcoin Improvement Proposals. Accessed 19 October 2026.