drand

Anyrand is build on top of drand, an open-source software that enables a consortium of nodes to continuously produce publicly verifiable randomness. drand utilises threshold BLS (Boneh-Lynn-Shacham) signatures, ensuring that the generated randomness is secure and unmanipulable (as BLS produces deterministic signatures). By requiring a subset of nodes to agree before a random value is produced, drand guarantees that no single node can withhold the randomness output, while ensuring high public availability of the produced random numbers.

Swapping out BLS12-381 with BN254

drand originally uses BLS signatures on the BLS12-381 curve. Unfortunately, verifying BLS12-381 signatures in the EVM is not cost-effective until EIP-2537 is included in Pectra. To address this, we implemented BLS on the BN254 curve, which is much more efficiently verifiable within the EVM. This adaptation has been successfully upstreamed into drand v2, allowing drand beacons to be efficiently verifiable in existing EVM implementations.

Developer preview limitations

To fully leverage the trust properties of the drand VRF system, we must wait for the official release and deployment of drand v2 by the League of Entropy. This new version incorporates the BN254 curve implementation that we contributed. Currently, in our developer preview version, we operate drand v1 with our BN254 curve implementation and we run all the nodes ourselves. Once drand v2 is released and adopted by the League of Entropy, Anyrand will be deployed with a new set of contracts that will verify the public beacons provided by the League of Entropy.