verifiable random function
Fuel VRF Secure and Provable Randomness
ORAO VRF generates secure, unbiased, and provable randomness for Fuel Network dApps using a multinode architecture and byzantine quorum. This technology ensures that the randomness is transparent and cannot be tampered with, making it ideal for various use cases that require trust and fairness. Fuel Network's high-performance blockchain provides fast and reliable execution of smart contracts, and with ORAO VRF, developers can add a layer of trust and security to their applications.
Fuel VRF developer's guide
Javascript SDK
Fuel VRF
JS library
has been recently updated to support latest Fuel SDK. We've built a
sample app
with minimal frontend to demo VRF offchain request and fulfillment in
JS.
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//import the library
import { Vrf } from "../lib/fuel/index.js";
//initialize VRF
const vrf = new Vrf(wallet!);
//initialize seed
const seed = new Uint8Array(32);
//request and await
await vrf.request(`0x${Buffer.from(seed).toString("hex")}`)
Sway SDK
The SDK is compatible with Fuel Testnet and Sway v0.60.0. Inside the SDK you'll find the
ORAO VRF library
and two apps:
The Rust SDK is documented in detail
on docs.rs.
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use vrf_abi::{randomness::{Fulfilled, Randomness, RandomnessState}, Vrf};
const VRF_ID = 0x749a7eefd3494f549a248cdcaaa174c1a19f0c1d7898fa7723b6b2f8ecc4828d;
/// Helper that calls "spin_and_pull_the_trigger" on a russian roulette instance.
pub async fn spin_and_pull_the_trigger(&self) -> anyhow::Result<()> {
// using random "force" - generates a boolean
let force = rand::random();
// we need to get the correct fee
let fee = self
.methods()
.round_cost()
.with_contract_ids(&[orao_fuel_vrf::CONTRACT_ID.into()])
.simulate()
.await?
.value;
println!("VRF fee is: {:?}", fee);
self.methods()
.spin_and_pull_the_trigger(Bits256(force))
.with_tx_policies(TxPolicies::default())
.call_params(CallParameters::default().with_amount(fee))?
.with_contract_ids(&[orao_fuel_vrf::CONTRACT_ID.into()])
.call()
.await?;
Ok(())
} Javascript SDK
Sway SDK
Request and fulfilment flow
ORAO VRF was designed to be secure, unbiased, affordable and fast randomness generator.
The request:
Client requests randomness from the on-chain contract. Multiple nodes
respond to the request by each generating randomness and signing it
on-chain.
The fulfillment:
The randomness request is fulfilled when nodes reach a byzantine
quorum. Client checks if its request for a given seed is fulfilled
and verifies the signatures.
