A pure-Rust VRF (Verifiable Random Function) implementation optimized for WASM environments, including web browsers and smart contracts.
This repository contains multiple crates for different use cases:
🌐 vrf-wasm/ - VRF for WASM environments (e.g browser workers)
Complete VRF implementation with key generation, signing, and verification:
- Key Generation: Secure VRF keypair creation
- Proof Generation: Create VRF proofs with randomness
- Verification: Verify VRF proofs and outputs
- WASM Compatible: Works in browsers and Node.js
- Size: 175KB optimized
Use for: Client-side applications, oracles, services that need full VRF functionality
🔗 vrf-wasm-js/ - JavaScript Bindings
Browser and Node.js bindings for the full VRF library:
- TypeScript Support: Full type definitions
- Easy Integration: Simple npm package
- Modern APIs: Promise-based async functions
📋 vrf-contract-verifier/ - NEAR Contract VRF Proof Verifier
NEW: Minimal verification-only library optimized for smart contracts:
- Ultra-Minimal: Only verification logic (86 bytes optimized)
- No-std Compatible: Works in constrained environments
- Multi-Platform: NEAR and generic WASM
- Battle Tested: Uses proven verification logic
- Fast: Optimized for contract gas costs
Use for: Smart contracts that only need to verify VRF proofs
| Feature | vrf-wasm | vrf-wasm-js | vrf-contract-verifier |
|---|---|---|---|
| Key Generation | ✅ | ✅ | ❌ |
| Proof Creation | ✅ | ✅ | ❌ |
| Proof Verification | ✅ | 8000✅ | ✅ |
| Browser Support | ✅ | ✅ | ❌ |
| Node.js Support | ✅ | ✅ | ❌ |
| NEAR Contracts | ❌ | ✅ | |
| Generic WASM | ❌ | ✅ | |
| Compiled Size | 175 KB | 267 KB | 86 bytes |
| Dependencies | Many | Many | Minimal |
Detailed comparison of compiled WASM binary sizes (optimized release builds with opt-level="s"):
| Library | Binary Size | Size Ratio | Use Case |
|---|---|---|---|
| vrf-contract-verifier | 86 bytes | 1x (baseline) | ✅ Proof verification only |
| vrf-wasm | 175 KB | 2,090x larger | ✅ Full VRF operations |
| vrf-wasm-js | 267 KB | 3,183x larger | ✅ Browser-optimized |
The 2,090x size difference between vrf-contract-verifier and vrf-wasm comes from:
-
Functionality Scope:
vrf-contract-verifier: Only verification logicvrf-wasm: Complete VRF implementation (keygen, signing, verification)
-
Dependencies:
vrf-contract-verifier: Minimal crypto primitives onlyvrf-wasm: RNG, serialization, encoding, multiple hash functions
-
Target Environment:
vrf-contract-verifier: Optimized for smart contracts where every byte countsvrf-wasm: General-purpose WASM environments
| Library | Debug Size | Optimized Release | Optimization Factor |
|---|---|---|---|
| vrf-wasm | 8.4 MB | 175 KB | 49x reduction |
| vrf-wasm-js | 10.1 MB | 267 KB | 39x reduction |
| vrf-contract-verifier | N/A | 86 bytes | Ultra-minimal |
- ✅ NEAR Protocol: Native integration with near-sdk
- ✅ Generic WASM: Any WASM-based contract platform such as Sui but this needs testing.
Both vrf-wasm and vrf-contract-verifier crates are designed for WASM environments:
- No std: Compatible with no-std environments
- No global statics: Avoids initialization issues
- Pure Rust: No external dependencies on system libraries
- Optimized builds: Minimal code size with
--releasebuilds
Implements ECVRF with:
- Curve: Ristretto255 (prime-order group over Curve25519)
- Hash Function: SHA-512
- Suite String:
sui_vrf - Output Length: 64 bytes
- Challenge Length: 16 bytes
// NEAR contract that verifies VRF proofs from authorized oracles
use vrf_contract_verifier::near::VrfVerifier;
#[near_bindgen]
impl RandomnessOracle {
pub fn submit_random(&mut self, proof: Vec<u8>, round: u64) -> bool {
let input = round.to_le_bytes();
self.verifier.verify_vrf(proof, self.oracle_pubkey.clone(), input.to_vec())
// ...
}
}// Generate verifiable randomness in browser
import { VRFKeyPairJS } from 'vrf-wasm-js';
const keypair = new VRFKeyPairJS();
const seed = crypto.getRandomValues(new Uint8Array(32));
const { hash, proof } = keypair.output(seed);
// hash can be used as randomness
// proof can be sent to contracts for verificationApache-2.0 - See LICENSE for details.