Solidity-compatible BLS signatures, threshold encryption, distributed key generation library in modern C++. Actively maintained and used by SKALE for consensus, distributed random number gen, inter-chain communication and protection of transactions. BLS threshold signatures can be verified in Solidity, and used as random beacon (common coin)
https://github.com/skalenetwork/internal-support/blob/main/docs/specifications/cryptography/bls-aggregated-signatures.md