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What is Chainlink VRF and Its Use Cases

VRF, which stands for "Verifiable Random Function," is the public key cryptographic hash function that proves that outputs are accurate. The hash can be calculated only by the owner of the private key. Everyone who has access to the private key can verify the integrity of the hash, regardless of who created it. Enumeration of hash-based data structures can be avoided with the use of VRFs. In a random event, the VRF ensures that smart contracts continue to perform as intended.

In the following sections, we will examine the VRF concept and how it relates to Chainlink, as well as how the VRF in Chainlink facilitates the operation of smart contracts in the blockchain.

Every node in the Ethereum ecosystem contributes to finding a solution to the problem and verifying the transaction. Once every node in the network has confirmed the faults, the information is sent out to the rest of the network. For instance, we design a decentralized application (dApp) in which we flip a coin and declare the side with the head to be the winner.

The forecast of heads and tails can be obtained using the discussed function. If you choose to operate a node, you can publish transactions only to that node; these transactions will not be shareable with other nodes. You will execute the randMod function, or you can also flip the coin until you have only shared the transaction after you have won. If you do either of these things, the transaction will only be shared after you have won.

The utilization of an oracle as a means of gaining access to a random number function that is not a component of the Ethereum blockchain is one method for dealing with this problem that has been proposed. In addition, you can investigate the many cryptographic methods and functions offered by third parties. These can be utilized but are not risk-free and require an audit.

What is Chainlink VRF?

Chainlink VRF, also known as Chainlink Verifiable Random Function, is a proven and validated link of randomness that has been meticulously curated for smart contracts. Chainlink VRF assists smart contract developers with a tamper-proof RNG, allowing them to design secure smart contracts for various applications. These applications rely on diverse and unpredictable outcomes, as described below:

  • NFTS and other blockchain-based games
  • Randomly distributing responsibilities and assets
  • Selection of a representative sample regarding the consensus procedure

Whenever a new request for a random outcome is made, the Chainlink VRF generates a random number and cryptographic proof proving the number's generation.

The resulting evidence is then validated and published on-chain before being employed by other apps. This procedure for generating proof ensures that the data cannot be tampered with or altered for the advantage of any third party. Using a source of randomness validated on-chain, Verifiable Random Function (VRF) enables smart contract developers to create more secure games utilizing a source of randomness that is certified on-chain. This also allows developers to provide more evidence to security-conscious users.

Now let's examine the operation of the Chainlink VRF while installing a smart contract on a blockchain platform.

Understanding VRF For Developers

A verifiable random function is a type of cryptographic function that takes a sequence of inputs, computes them, and generates a pseudorandom output, along with a proof of authenticity that anybody can check. This type of function is known as a verifiable random function.

Inputs for a VRF typically consist of a public-private key pair and a seed. This type of combination is sometimes referred to as verification and secret keys. Public and private keys will be generated, and a seed will be chosen. These values are then sent to the VRF, which generates a random number by employing the private key in conjunction with the source. After then, the VRF will generate a random number in addition to proof. In a crucial sense, proof development makes the function verifiable, and maintaining the secrecy of the private key guarantees that the number will always be unpredictable.

Verifiable random functions are characterized by their fundamental characteristics, which are reflected in the function's name.

Verifiable — Anyone can check whether or not the random number that a VRF created is correct. The only thing that is required of them is to look over the evidence and ensure that the hash output is correct. The person who possesses the VRF secret key is the only one who can compute the hash, but anyone who has the VRF public key can verify that the hash is correct.

Random — The output of a VRF is entirely unpredictable (uniformly dispersed) to anyone unaware of the seed or the private key, and it does not adhere to any pattern. Every conceivable output has an equal chance of occurring in a VRF. The source and the private key are combined in a one-of-a-kind fashion to produce the needed randomness.

Functions — VRFs are designed to perform their function by utilizing a mathematical procedure to generate a random number and proof that validates the number's legitimacy. For a function to be considered a VRF, the random number generator (RNG) must keep the seed hidden (implicit) so that it can continue to maintain its unpredictability.

On the other hand, the proof must be explicit and calculable by everyone (explicit) to continue to support its verifiability.

VRF is used in the consensus methods of a variety of layer-1 blockchains, including Algorand, Cardano, Internet Computer, and Polkadot development.

Smart contract developers demand a source of randomization for their applications outside the blockchain technology ecosystem.

However, due to the deterministic nature of blockchain networks, on-chain apps do not have access to a safe RNG. Using on-chain blockhashes for randomness might lead to manipulation by blockchain miners/validators, who can delete blocks with unfavorable hashes and "re-roll the dice," modifying the RNG value. Simple off-chain solutions are opaque and do not confirm that the RNG value generated is valid and has not been tampered with by either the data source or the Oracle node.

Well-designed randomness-based systems ideally want it to be provably fair and equally unpredictable to all contract participants and decrease the chance that an adversary may exploit contracts by forecasting their results.

Smart contract development can be used in conjunction with Chainlink VRF to create applications that make use of randomness in a secure and verifiable way. For example, a smart contract could be written to incorporate a Chainlink VRF to generate random numbers for a lottery game, and the results of the random number generation could be stored on the blockchain for transparency and immutability.

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UseCases of Chainlink VRF

Chainlink VRF is the industry's most secure random number generator (RNG). This means that smart contracts and off-chain systems can use it to get random numbers that can't be changed. Chainlink VRF has handled more than a million requests for fair and unbiased random numbers on Ethereum, Polygon, and Binance Smart Chain since its mainnet launch in October 2020. For various purposes, these random numbers have been used in blockchain games, NFTs, and DeFi.

Fair Gaming Traits Generation

Users receive the smart lottery contract, which confirms that only random data is used to choose the winners. Blockchain participants can confirm this random data. Users are given the confidence and certainty to engage in the smart contract with the knowledge that they have a winning probability. For example, Pooltogether is an Ethereum-based verified deposit lottery game. It is a principal-secured savings game that pools the user's money, conducts a daily or weekly lottery, and awards the deposit plus interest to the winner. The game incentivizes users to save using a lottery method.

Pooltogether utilizes chainlink VRF to generate verifiable random numbers, allowing users to verify that absolute random numbers select each issue's winners. In addition to ensuring the users' security, it ensures that the key hints and the security of the key links can be traced and that the random number generation process can be thoroughly examined.

Interactive Onchain Artwork

With the aid of Chainlink VRF, you can also enhance your knowledge of uncertain settings and unforeseen situations. You can determine the outcomes of PvP battles and other dynamic events through strategy and enjoyment.

Facegolf, for instance, employs the Chainlink VRF to obtain a safe and on-chain randomness solution. This prevents them from exposing their future users to the various criminal behaviors they have previously encountered.

NFT Distribution in P2E Games

Most video games feature distinct characters, each with its characteristics. Some characters are frequent, while others are quite uncommon. Determining how new characters are given to users is crucial to ensuring a fair game, particularly in blockchain-based games where specific characters might offer players more monetary benefits.

Axie Infinity is one of the most popular play-to-earn blockchain games, in which participants fight, breed, and trade Axies, which are non-fungible tokens. Each of the six components of an Axie, the back, ears, eyes, horn, mouth, and tail, has various base statistics and possible qualities. Axie Infinity incorporated Chainlink VRF to ensure that each 4088 Origin Axies created had a unique set of attributes based on the predetermined probabilities mentioned in their smart contract.

Chainlink VRF provides not only technically fantastic functionality but also advocates digital art by adding a creative dimension of entropy to the user experience. The randomness employed in NFT processes must adhere to the highest standards of fairness and transparency, which Chainlink VRF can deliver for the ecosystem.

Fair Cross-Chain NFT Transfer and Upgrade

Decentralized finance businesses emphasize multi-chain NFT stages. Cross-chain NFT commercial center development focuses on NFT stage pain points.

Cross-chain NFT marketplaces address interoperability, maintainability, and energy efficiency. Focusing on cross-chain NFT stages will revolutionize the Metaverse development. Moving to Metaverse is called the Key to the Metaverse. The keys will control Metaverse apps.

Metaverse, for example, is confined to not only one blockchain network but all blockchain systems. Those holding Ethereum blockchain keys can move them to Solana or another blockchain.

Often, the market requires cross-chain NFT stages.

OpenSea, a popular NFT marketplace, is also implementing cross-chain compliance.

Oracles Are Revolutionizing Cryptographic Truths

The decentralized finance (DeFi) business represents the first large-scale deployment of hybrid smart contracts, combining trust-minimized code on a blockchain with decentralized oracle networks (DONs) enable secure, dependable access to external systems and real-world information.

This straightforward definition of oracles is an excellent starting point, but it is only that. Chainlink Co-founder Sergey Nazarov described numerous significant stages in the evolution of oracles.

Oracles are responsible for distributing data and transferring information into another environment, such as a blockchain, in their basic form.

Oracles are responsible for certifying definitive truth in their more sophisticated forms, which exist on a continuum between objective theoretical truth and personal subjective truth. As Nazarov noted in a recent edition of the Lex Fridman podcast, definitive truth (as it relates to DeFi) is established to serve the same goal of a hybrid smart contract that executes on preset and mutually agreed-upon conditions.

For instance, a DON establishes the definitive truth on the price of a given asset by aggregating pricing data from different sources and reaching a consensus among a large number of independent node operators. Nazarov stated to Bennington that while the initial value of oracles is merely the giving of information, the advanced value of prophets is validating that information in terms of absolute truth.

Oracles are advancing beyond the formation of conclusive truth capable of securing billions and eventually trillions of dollars worth of value to the capacity to execute trust-minimized computing. This and other decentralized services are already powering hybrid smart contracts transforming the insurance business, gaming, global trade, advertising networks, and more.

As the leading decentralized oracle service in the world, the Chainlink development network today consists of hundreds of DONs providing the data, computing, and verifiable random number generation necessary for developing increasingly sophisticated hybrid smart contracts. As Nazarov demonstrated in an April episode of the Hidden Forces podcast utilizing the flower patch analogy, there is no foreseeable limit to the number of Chainlink DONs and their power to generate a cryptographically assured universe.

Let's build together on Chainlink

Work With Us To Leverage the Power of Chainlink VRF

With Chainlink VRF v2's foremost cost-effectiveness and usability enhancements, it has never been simpler for developers to design sophisticated smart contract applications with truly random outcomes provably fair gaming. While we have offered a few examples of what is possible with verifiable randomness, the number of potential use cases is virtually unlimited.

If you're a developer looking to connect your application to Chainlink VRF easily, browse the developer documentation, test out the subscription management application, and join the technical discussion on Discord. Contact our expert if you wish to book a call to discuss your integration in greater detail.

We also encourage developers to use Chainlink VRF v2 with other Chainlink decentralized services in their apps, such as Chainlink Automation for automating on-chain transactions based on predefined conditions (like starting/ending game rounds at certain times), Chainlink Price Feeds to find out the current value of in-game assets on marketplaces. Chainlink Data Feeds to improve in-game processes based on external events (like the weather or a sports score).


Chainlink Oracle's network contains more than a thousand nodes of the highest possible standard. The network is rendered effectively scalable and decentralized in nature in a manner that is cost-effective when threshold signature technology is utilized. With the growing requirement to implement smart contracts in the blockchain ecosystem, chainlink VRF delivers a secure way of generating random numbers for easy probability in various gaming sectors. This will bring a superior level of decentralization and availability to Chainlink VRF.

Next Article

A Comprehensive Guide on Hybrid Smart Contracts


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