5 min readNov 13, 2020

Yoink now harnessing the power of Chainlink VRF to Select Daily Winners!

Howdy fellow Yoinkers! 🐷 We are extremely proud to share that we have integrated Chainlink’s newly launched VRF (Verifiable Random Function) as part of our daily Yoinking process in order to provide a fully transparent, on-chain, and first of its kind solution to the problem of generating secure, provably fair randomness in our daily draw.

It is extremely important to the Yoink team that we can be completely candid on-chain in how the daily prize winner is selected. We have been working diligently over the last few weeks to complete this integration and are immensely proud to announce that we are now live and taking full advantage of the power of Chainlink Oracles every…single…day!

The Yoink team would like to express their gratitude to the developers of Chainlink for the smooth and seamless integration of VRF with the Yoink protocol. Not only because it’s being used in Yoink but it allows developers to be even more creative and push the boundaries of blockchain far beyond what was possible on chain before.

By utilising Chainlink’s VRF, we further solidify and legitimise Yoink. We are here to stay, and will continue to expand and develop the Yoink ecosystem.

Please take a look at our website and join our active Telegram community. The dashboard for the Yoinking process can be found here.

Yoink?

Yes, Yoink! In case you have been living under a rock, let’s go over the basics. Every day at 22:00 UTC there is a daily draw from all holders of YNK (min 1K YNK to qualify*). If the wallet selected is in the top 500 YNK holders (check eligibility here), they get to Yoink 1% of the piggy bank to themselves. If not, the YNK is burned! 🔥🔥🔥

Y-N-K in G-I-F form!

*Since we cannot dynamically change the range for holder balances, we have switched from a minimum balance of 1K YNK to the top 899 wallets.

Piggy Bank?

The piggy bank initially contained 30% of the supply (30m YNK), and since October 1st 2020, there is a daily chance to win 1% of its contents!

Remember kids, piggy banks are for saving, not just spending 😉. More details on that to come in the following months.

What is Chainlink VRF?

In order to achieve a truly random selection process, Yoink will be utilising the power of Chainlink’s on-chain random number generator dubbed VRF (Verifiable Random Function). We use Chainlink VRF to determine the daily winner of our Piggy Bank draw. Before Chainlink VRF, there was no possible way to generate a random number on-chain in a highly secure manner not gameable by miners.

Our smart contract requests randomness by providing a seed to Chainlink oracles. The seed, which should be unpredictable to the oracles, is used to generate a random number, which is then sent to our contract on-chain. By utilising Chainlink VRF, Yoink is able to ensure participants that the chosen wallet address happens in a provably fair and fully transparent manner, which the Yoink developers or external entities cannot tamper with. The entire process is auditable by all participants via on-chain cryptographic proofs provided by the Chainlink oracles.

Technical Integration details

The random number generated by Chainlink VRF will be used to pick a wallet address from the array as an index. Once the number is generated, it is mathematically cut off by the following formula: a mod 1000 resulting in a 3 digit number always lower than 1000.

This will return a number in the range of 100 to 999, which shall be equivalent to YNK holder wallets 1 to 899.

If the number generated by Chainlink’s VRF is > 500, the smart contract will burn the tokens. If it’s <= 500, the tokens of that day will be paid out to their winner. The amount of tokens Yoinked (deducted) each day is 1% of the total remaining balance of the Piggybank 🏦.

Piggybank Contract:0xb6beE35e841ee9a1b0f7c8DB5BC1F3A4cE4286D6

Reasons for VRF Integration

There are a multitude of reasons Yoink has decided to integrate Chainlink VRF, but to name a few:

Meet the high trust requirements of Yoink participants and provide assurance to users that the draw is being executed fairly in a decentralised manner.
Make Yoink more robust by using a source of randomness that is verifiable on-chain.
Ensure participants always have full transparency of what is happening in the backend of the process.
Chainlink has a strong reputation of providing robust oracle solutions that secure billions of dollars in value for many DeFi projects, and it is an honour to join their ecosystem utilising VRF.

We are super excited about this integration and look forward to growing the Yoink ecosystem in the months and years to come!

About Chainlink

Chainlink is the most widely used and secure way to power universal smart contracts. With Chainlink, developers can connect any blockchain with high-quality data sources from other blockchains as well as real-world data. Managed by a global, decentralized community of hundreds of thousands of people, Chainlink is introducing a fairer model for contracts. Its network currently secures billions of dollars in value for smart contracts across the decentralized finance (DeFi), insurance and gaming ecosystems, among others.

Chainlink is trusted by hundreds of organizations to deliver definitive truth via secure, reliable data feeds. To learn more, visit chain.link and follow @chainlink on Twitter.

About Yoink

Yoink is a simple yet elegant protocol encompassing deflationary characteristics, with a sneaky little twist. Anyone can participate and get Yoinked!

Please take a look at our website and join our active Telegram community. The dashboard for the Yoinking process can be found here.

For more information: