CroxSwap Integrates Chainlink VRF to Help Determine Lucky Draw Winners

5 min readJul 11, 2022


croxswap-chainlink integration

We’re excited to announce that CroxSwap — a decentralized dual farming and staking platform — has integrated Chainlink Verifiable Random Function (VRF) on BNB Chain mainnet. By integrating the industry-leading decentralized oracle network, we now have access to a tamper-proof and auditable source of randomness needed to help determine winners in our lucky draw. Ultimately this creates a more exciting and transparent user experience, as users can independently verify that draw outcomes are fair.

CroxSwap is a decentralized yield farming platform that’s built on multiple blockchains, including BNB and HECO Chains. CroxSwap aims to create an environment that is completely safe, fair, and convenient for all players. To that end, all logic for vaults and lucky draws are executed using smart contracts, with cheating prevention measures, no-loss pots, and instant payouts.

VPOTS Feature:
VPOTS = Vaults + Jackpots. It is a unique approach to creating competitive staking with the added bonus of potentially winning a reward. VPOTS is divided into two phases.

Phase 1 is the Vault phase where users deposit their assets into the Vault to earn rewards with a minimum deposit fee of around 5%. As it is a competitive staking game, early depositors will earn the 3% fee paid by new depositors. In other words, each time a new deposit takes place in the vault, previous depositors earn a flat 3% share for parking their tokens in the vault. 1% of new deposits is supplied to the lucky draw pool and the remaining 1% from the deposit fee goes to the Crox liquidity pool.

In Phase 2, the lucky draw is enabled. The lucky draw happens every 15 days. The deposit fees accumulated throughout the 15 day period are converted into the Prize Pool. This is where Chainlink VRF is used to help pick a random winner for each draw.

In order to help ensure that the randomness supporting the lucky draw is provably fair, we needed access to a secure random number generator (RNG) that any user could independently audit. However, RNG solutions for smart contracts require several security considerations to prevent manipulation and ensure system integrity. For instance, RNG solutions derived from blockchain data like block hashes can be exploited by miners/validators, while off-chain RNG solutions derived from off-chain APIs are opaque and don’t provide users with definitive proof about the integrity of the process.

After reviewing various solutions, we selected Chainlink VRF because it’s based on cutting-edge academic research, supported by a time-tested oracle network, and secured through the generation and on-chain verification of cryptographic proofs that prove the integrity of each random number supplied to smart contracts.

Chainlink VRF works by combining block data that is still unknown when the request is made with the oracle node’s pre-committed private key to generate both a random number and a cryptographic proof. The CroxSwap smart contract will only accept the random number input if it has a valid cryptographic proof, and the cryptographic proof can only be generated if the VRF process is tamper-proof. This provides our users with automated and verifiable assurances directly on-chain that game outcomes supported by Chainlink VRF are provably fair and were not tampered with by the oracle, outside entities, or the CroxSwap team.

CroxSwap also intends to launch on Polygon, Fantom, and other EVM-based networks and implement Chainlink VRF on those networks as our preferred randomness solution. Other Chainlink services, such as Chainlink Price Feeds and Chainlink Keepers, are also being considered for future products such as a DEX and bridge aggregator.

“Providing our community with a high standard of transparency is essential, which made integrating Chainlink an obvious decision. Now, our users can independently verify that the random number generator used to help select winners in our lucky draw is provably fair.” — CroxSwap team

About Chainlink

Chainlink is the industry standard for building, accessing, and selling oracle services needed to power hybrid smart contracts on any blockchain. Chainlink oracle networks provide smart contracts with a way to reliably connect to any external API and leverage secure off-chain computations for enabling feature-rich applications. Chainlink currently secures tens of billions of dollars across DeFi, insurance, gaming, and other major industries, and offers global enterprises and leading data providers a universal gateway to all blockchains.

Learn more about Chainlink by visiting or reading the developer documentation at To discuss an integration, reach out to an expert.

About Croxswap

CroxSwap is a decentralized next-generation multichain yield farming protocol which offers dual rewards for staking and farming. CroxSwap’s cross-chain bridge aggregator (in progress) will be the cheaper & faster service to transfer your assets across networks without any hassle.

Farming-as-a-Service: CroxSwap is trying to solve the missing piece of a puzzle in DeFi by providing the liquidity creation service for everyone. With farming as a service, we offer liquidity mining to all BNB and HECO projects regardless of their LP type. Our flexible protocol supports current and upcoming projects that are looking to gain liquidity without any extra cost.

Staking-as-a-service: If you are a project with a use-case different from yield farming and staking but would like to provide a staking pool for your holders, CroxSwap is the place to go. We offer no fee-staking pools that can be deployed in minutes and make them available for your community. It doesn’t involve any cost to you other than providing rewards to the liquidity providers.

Dual Rewards in farming: Our innovation in yield farming provides an opportunity to earn two tokens as rewards by providing liquidity. This helps in recovering the impermanent loss faster than regular yield farms. High APR yield generated from dual-farms encourage more users to provide liquidity which is a win-win deal for both project owners and liquidity providers.

Our farming and staking as a service is designed to help other projects to launch their liquidity farms & pools to reduce their development cost, maintenance and save time.

Croxswap links:








A dual-farming & staking protocol where any project can create their own pools to gain liquidity