Using garaga libraries in your Cairo project

Garaga provides a powerful Cairo library for elliptic curve operations, signature verification, and cryptographic primitives. The library is designed to work uniformly across all supported curves—the same functions, the same patterns, just change the curve identifier.

Installation

Garaga is available on the scarbs.xyz registry. Add it to your project using scarb add:

scarb add garaga

Or add it manually to your Scarb.toml:

Scarb.toml

[dependencies]
garaga = "1.0.1"

[cairo]
sierra-replace-ids = false # Required to avoid compilation errors

Using the registry is the recommended approach. For more details on managing dependencies, see the Scarb documentation.

Important: The sierra-replace-ids = false setting is required. See issue #198 for details about using Garaga with workspaces.

Installing from Git (alternative)

If you need a specific commit or unreleased version, you can install from Git:

[dependencies]
garaga = { git = "https://github.com/keep-starknet-strange/garaga.git", tag = "v1.0.1" }

---

Generic Over Any Curve

One of Garaga's key architectural decisions is that all operations work uniformly across any supported curve. This means:

• ✅ The same msm_g1 function works for BN254, BLS12-381, SECP256K1, and more

• ✅ The same signature verification patterns apply to all curves

• ✅ Switching curves requires only changing the curve_id parameter

• ✅ Future curves can be added without changing your code

Example: Curve-Agnostic MSM

use garaga::ec_ops::msm_g1;
use garaga::definitions::{G1Point, u384};

// This exact same function works for ANY supported curve
fn compute_msm(
    points: Span<G1Point>,
    scalars: Span<u256>,
    curve_id: usize,  // Just change this to switch curves!
    hints: Span<felt252>,
) -> G1Point {
    msm_g1(points, scalars, hints, curve_id)
}

// Usage:
// compute_msm(points, scalars, 0, hints)  // BN254
// compute_msm(points, scalars, 2, hints)  // SECP256K1
// compute_msm(points, scalars, 3, hints)  // SECP256R1

This design enables maximum code reuse and flexibility across your applications.

---

Supported Elliptic Curves

Curve ID	Curve	Common Use Cases
0	BN254	Ethereum zkSNARKs, Groth16
1	BLS12-381	Ethereum 2.0, Zcash, drand
2	SECP256K1	Bitcoin, Ethereum ECDSA
3	SECP256R1	WebAuthn, TLS, P-256
4	ED25519	Solana, SSH, general EdDSA
5	GRUMPKIN	Noir circuits, Aztec

These curve identifiers are consistent across all Garaga code—Cairo, Python, Rust, and TypeScript. Use the same ID everywhere.

---

Available Operations

Elliptic Curve Operations

Operation	Description	Curves
Multi-Scalar Multiplication (MSM)	Compute ∑ sᵢ·Pᵢ efficiently	All
Scalar Multiplication	Compute s·P for a single point	All
Point Addition	Add two elliptic curve points	All
Pairing Check	Verify pairing equations	BN254, BLS12-381

→ EC Operations Documentation

Signature Verification

Scheme	Description	Curves
ECDSA	Standard elliptic curve signatures	SECP256K1, SECP256R1, BN254, BLS12-381
Schnorr	BIP340-compatible Schnorr signatures	All Weierstrass curves
EdDSA	Edwards-curve signatures	ED25519

→ Signatures Documentation

Hashing Functions

Function	Description	Use Case
SHA-512	Standard SHA-512	EdDSA, general hashing
Poseidon (BN254)	ZK-friendly hash	Grumpkin circuits

→ Hashing Documentation

---

Performance Characteristics

Garaga achieves efficiency through precomputed hints. The SDK (Python/Rust/TypeScript) generates these hints off-chain, and the Cairo code verifies them on-chain. This means:

1. Off-chain: Complex computations happen in the SDK

2. On-chain: Cairo only verifies the results are correct

┌─────────────────────────────────────────────────────────────┐
│  Off-chain (SDK)                                            │
│  - Compute MSM/signature verification                       │
│  - Generate verification hints                              │
│  - Serialize as calldata                                    │
└───────────────────────────┬─────────────────────────────────┘
                            │ calldata with hints
                            ▼
┌─────────────────────────────────────────────────────────────┐
│  On-chain (Cairo)                                           │
│  - Deserialize calldata                                     │
│  - Verify hints are correct                                 │
│  - Return result (success/failure)                          │
└─────────────────────────────────────────────────────────────┘

This architecture enables operations that would otherwise be prohibitively expensive on-chain.

---

Next Steps

• EC Multi-Scalar Multiplication — Compute MSMs on any curve

• Signature Verification — ECDSA, Schnorr, and EdDSA

• Hashing Functions — SHA-512 and Poseidon