Inside the Entropy

The article discusses the importance of generating verifiable randomness for various applications such as lotteries, cryptographic computations, and scientific experiments. It introduces a new public randomness beacon by Cloudflare as part of the League of Entropy initiative. This network of beacons produces distributed, publicly verifiable random outputs that can be used in applications where the nature of the randomness must be publicly audited. The underlying cryptographic architecture is based on the drand project. The article also provides a technical overview behind the cryptography used in the distributed randomness beacon and how it can be used to generate publicly verifiable randomness. It explains the concept of entropy, sampling randomness from natural phenomena or external usage characteristics, and the use of threshold cryptography for generating distributed randomness. The drand project uses a distributed key generation (DKG) procedure and a threshold signature scheme as its core components. The DKG procedure creates a distributed secret key that is formed of n different key pairs, each one being held by an entity in the system. The threshold signature scheme allows a set of users holding distributed key-pairs to compute intermediate signatures that can be combined to create an entire signature for the system. The drand protocol involves synchronizing randomness beacons in rounds and producing new signatures using private keys on the previous signature generated and the round ID. These signatures are usually broadcasted, allowing any client to publicly verify the signature over this data to verify that the beacons honestly aggregate. The randomness can be retrieved by combining the signatures from each of the beacons using the threshold property of the scheme. The article concludes with a discussion on how drand works and its potential applications in building a better internet, as well as acknowledging the collaborators involved in the League of Entropy initiative.