Consensus
Quantum Coin mainnet uses 3 phase pBFT consensus (proof of stake) that achieves immediate finality after a block has been created. Higher timeouts are used to increase liveness, within limits of the FLP theorem.
Though the protocol can support more than 2 rounds of validator voting, the current implementation limits the maximum rounds to 2, to reduce livenes problems that are outlined in the FLP theorm.
Read more in Consensus Whitepaper.