WHAT IS A DECENTRALIZED RANDOMNESS BEACON?

A Decentralized Randomness Beacon allows a group of participants to generate a random value that is public and common, even if some participants are dishonest. Its applications are diverse: from lotteries and games, consensus protocols, fair transaction ordering, and election audits to Zero-Knowledge Proofs.

Over the years, public randomness generation has drawn consistent interest from the cryptographic research community. Various distributed systems, including different consensus mechanisms, anonymous networks like Tor, and blockchain systems, assume access to such public randomness. For example, in recent Proof of Stake blockchains, miners are randomly selected each epoch via a common random source. However, a significant missing piece is a bias-resistant, distributed, and scalable public randomness source. While several centralized solutions exist, such as the randomness beacons operated by NIST or a source from the University of Chile, these beacons cannot be verified or decentralized. Verifiability is crucial for systems like Proof of Stake, where a block producer must prove they were elected as a miner for a given epoch. Decentralization enhances the beacon's robustness.

Decentralized Randomness Beacons (DRBs) aim to enable a group of participants to collectively compute a random result, preventing any single participant or coalition from predicting or biasing the outcome. DRBs have multiple applications, including verifiable lotteries and leader elections in distributed consensus protocols. Here are some potential uses:

• Random sampling in a distributed network: In distributed systems, random sampling might be necessary to ensure fairness and security in various processes.

• In distributed systems, it is often necessary to randomly select a sample of nodes for specific tasks. Blockchain systems, for instance, frequently require a source of randomness for various purposes, such as electing block proposers, forming a consensus group, shuffling validators, or assigning tasks within a distributed network. Decentralized Randomness Beacons (DRBs) can be utilized to generate random numbers that no single party can predict or manipulate.

• In decentralized lottery mechanisms, ensuring the fairness of the draw is paramount. A decentralized and verifiable randomness beacon that cannot be tampered with by any party would be an ideal solution. This is also applicable to other types of games that require randomness.

In any distributed decision-making process, from voting systems to collective governance protocols, there might be a need to randomly select participants for certain roles, responsibilities, or privileges. A publicly verifiable source of randomness is critical in these systems.

The success of all these applications relies not only on the unpredictability and impartiality of the randomness but also on its public verifiability, which our protocol achieves. This ensures a high level of trust and fairness in all these applications.

Effectively implementing these decentralized randomness beacons will bring about numerous benefits:

• Decentralized Random Beacons (DRBs) are central to many distributed systems and cryptographic applications, such as blockchains and smart contracts. They ensure fairness, security, and reliability by generating random numbers in a manner that no participant or coalition of participants can predict or bias the outcome. This work contributes to the design of safer, more efficient, and fairer distributed systems.

• Current solutions for Distributed Key Generation (DKG) either require extensive communication between participants, which is cumbersome, or necessitate each participant to publish a large amount of data, making the process slow and inefficient. By proposing a more efficient protocol, we contribute to making these cryptographic systems more practical for real-world use.

• DRBs ensure that random numbers are not only secure and unpredictable but also publicly verifiable. This adds an extra layer of security and trust, as anyone can verify that the random numbers have been correctly computed, without needing to trust any party within the system.

• DRBs can be customized in design to be as compatible as possible with blockchains such as Ethereum, one of the most popular blockchain platforms, to support the adoption of the protocol in the blockchain and cryptocurrency industry.