> ## Documentation Index
> Fetch the complete documentation index at: https://litprotocol-feat-rusk-sdk.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Threshold Cryptography

Lit Protocol supports a wide range of elliptic curves and signing schemes, all securely implemented using threshold cryptography and threshold consensus within a trusted execution environment (TEE).

## Supported Elliptic Curves and Signing Schemes

| Signing Scheme                                                     | Curves                   | Crates (Rust)                                                                                                              | `CurveType`      | `SigningScheme`                |
| ------------------------------------------------------------------ | ------------------------ | -------------------------------------------------------------------------------------------------------------------------- | ---------------- | ------------------------------ |
| **ECDSA** ([Damgård et al.](https://eprint.iacr.org/2020/501.pdf)) | secp256k1                | [`k256`](https://crates.io/crates/k256)                                                                                    | `K256`           | `EcdsaK256Sha256`              |
|                                                                    | P-256 (secp256r1)        | [`p256`](https://crates.io/crates/p256)                                                                                    | `P256`           | `EcdsaP256Sha256`              |
|                                                                    | P-384 (secp384r1)        | [`p384`](https://crates.io/crates/p384)                                                                                    | `P384`           | `EcdsaP384Sha384`              |
| **Schnorr** (FROST)                                                | secp256k1                | [`k256`](https://crates.io/crates/k256)                                                                                    | `K256`           | `SchnorrK256Sha256`            |
|                                                                    | secp256k1 (Taproot)      | [`k256`](https://crates.io/crates/k256)                                                                                    | `K256`           | `SchnorrK256Taproot`           |
|                                                                    | P-256 (secp256r1)        | [`p256`](https://crates.io/crates/p256)                                                                                    | `P256`           | `SchnorrP256Sha256`            |
|                                                                    | P-384 (secp384r1)        | [`p384`](https://crates.io/crates/p384)                                                                                    | `P384`           | `SchnorrP384Sha384`            |
|                                                                    | Ed25519                  | [`curve25519-dalek`](https://crates.io/crates/curve25519-dalek), [`ed25519-dalek`](https://crates.io/crates/ed25519-dalek) | `Ed25519`        | `SchnorrEd25519Sha512`         |
|                                                                    | Ristretto25519           | [`curve25519-dalek`](https://crates.io/crates/curve25519-dalek)                                                            | `Ristretto25519` | `SchnorrRistretto25519Sha512`  |
|                                                                    | Ristretto25519 (sr25519) | [`curve25519-dalek`](https://crates.io/crates/curve25519-dalek)                                                            | `Ristretto25519` | `SchnorrkelSubstrate`          |
|                                                                    | Ed448                    | [`ed448-goldilocks`](https://crates.io/crates/ed448-goldilocks)                                                            | `Ed448`          | `SchnorrEd448Shake256`         |
|                                                                    | RedJubjub                | [`jubjub`](https://crates.io/crates/jubjub)                                                                                | `RedJubjub`      | `SchnorrRedJubjubBlake2b512`   |
|                                                                    | RedDecaf377              | [`decaf377`](https://crates.io/crates/decaf377)                                                                            | `RedDecaf377`    | `SchnorrRedDecaf377Blake2b512` |
| **BLS** (Basic, MsgAug, PoP)                                       | BLS12-381 (G2)           | [`blstrs-plus`](https://crates.io/crates/blstrs-plus), `blsful`                                                            | `BLS`            | `Bls12381`                     |
|                                                                    | BLS12-381 (G1)           | [`blstrs-plus`](https://crates.io/crates/blstrs-plus), `blsful`                                                            | `BLS12381G1`     | `Bls12381G1ProofOfPossession`  |

## Supported Chains

### secp256k1 (K256) with ECDSA

**Bitcoin Ecosystem:**

* Bitcoin (BTC) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Bitcoin Cash (BCH) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Bitcoin SV (BSV) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Litecoin (LTC) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Dogecoin (DOGE) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Zcash (ZEC) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Dash (DASH) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Decred (DCR) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`

**Ethereum Ecosystem:**

* Ethereum (ETH) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Ethereum Classic (ETC) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Polygon (MATIC) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Binance Smart Chain (BNB) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Avalanche (AVAX) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Fantom (FTM) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Arbitrum - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Optimism - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Base - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* zkSync - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Linea - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Scroll - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Gnosis Chain (xDai) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`

**Cosmos Ecosystem:**

* Cosmos (ATOM) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`

**Other secp256k1 Chains:**

* Tron (TRX) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* VeChain (VET) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* EOS - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Theta Network (THETA) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Qtum (QTUM) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Zilliqa (ZIL) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* ICON (ICX) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* DigiByte (DGB) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Komodo (KMD) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Verge (XVG) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Ravencoin (RVN) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`
* Horizen (ZEN) - `CurveType::K256`, `SigningScheme::EcdsaK256Sha256`

### secp256k1 (K256) with Schnorr

* Bitcoin (Taproot) - `CurveType::K256`, `SigningScheme::SchnorrK256Taproot`

### P-256 (secp256r1) with ECDSA

* Flow - `CurveType::P256`, `SigningScheme::EcdsaP256Sha256`
* NEO - `CurveType::P256`, `SigningScheme::EcdsaP256Sha256`
* Ontology (ONT) - `CurveType::P256`, `SigningScheme::EcdsaP256Sha256`
* Hyperledger Fabric - `CurveType::P256`, `SigningScheme::EcdsaP256Sha256`
* Tezos (optional) - `CurveType::P256`, `SigningScheme::EcdsaP256Sha256`
* WebAuthn / Passkeys - `CurveType::P256`, `SigningScheme::EcdsaP256Sha256`

### P-384 (secp384r1) with ECDSA

* Enterprise PKI systems - `CurveType::P384`, `SigningScheme::EcdsaP384Sha384`
* Government and high-security applications - `CurveType::P384`, `SigningScheme::EcdsaP384Sha384`

### Ed25519 with EdDSA (Schnorr)

* Solana (SOL) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Stellar (XLM) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Cardano (ADA) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Algorand (ALGO) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Hedera Hashgraph (HBAR) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Elrond (EGLD) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Tezos (optional) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Ripple (XRP, optional) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* NEM (XEM) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Waves (WAVES) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Lisk (LSK) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Nano (NANO) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Siacoin (SC) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`
* Monero (XMR, variant) - `CurveType::Ed25519`, `SigningScheme::SchnorrEd25519Sha512`

### Ristretto25519 with Schnorr/Schnorrkel

* Polkadot (DOT, sr25519) - `CurveType::Ristretto25519`, `SigningScheme::SchnorrkelSubstrate`
* Kusama (KSM, sr25519) - `CurveType::Ristretto25519`, `SigningScheme::SchnorrkelSubstrate`
* All Polkadot Parachains (sr25519) - `CurveType::Ristretto25519`, `SigningScheme::SchnorrkelSubstrate`
* All Substrate-based chains (sr25519) - `CurveType::Ristretto25519`, `SigningScheme::SchnorrkelSubstrate`

### Ed448 with Schnorr

* Research and experimental protocols - `CurveType::Ed448`, `SigningScheme::SchnorrEd448Shake256`
* High-security government applications - `CurveType::Ed448`, `SigningScheme::SchnorrEd448Shake256`

### RedJubjub with Schnorr

* Zcash (Sapling shielded transactions) - `CurveType::RedJubjub`, `SigningScheme::SchnorrRedJubjubBlake2b512`

### RedDecaf377 with Schnorr (RedDSA)

* Penumbra - `CurveType::RedDecaf377`, `SigningScheme::SchnorrRedDecaf377Blake2b512`

### BLS12-381 with BLS Signatures

* Ethereum (Consensus Layer / Beacon Chain) - `CurveType::BLS`, `SigningScheme::Bls12381`
* Filecoin (FIL) - `CurveType::BLS`, `SigningScheme::Bls12381`
* Chia (XCH) - `CurveType::BLS`, `SigningScheme::Bls12381`
* Dfinity (ICP) - `CurveType::BLS`, `SigningScheme::Bls12381`

## Key Derivation

Key derivation is done additively and uses all 10 root keys per curve to derive child keys, based on [Groth and Shoup 2022](https://eprint.iacr.org/2021/1330.pdf).