A Distributed Clock Synchronization Protocol for Proof of Stake Blockchains

In a Proof of Stake (PoS) blockchain, all nodes need to be able to recognize approximately synchronized clocks. A PoS blockchain relies on external clocks, and each node synchronizes its local clock according to an external clock using Network Time Protocol (NTP) or a similar protocol. However, this external dependence is undesirable because it reduces the autonomy, sustainability and trustless nature of the blockchain. This paper presents a clock synchronization protocol for slot-based PoS blockchains. The proposed protocol estimates the block propagation time to ensure that the synchronization is closer to that of a real-world clock. In addition, the proposed method considers the clock drift and clock adjustment frequency to achieve more accurate synchronization. Simulation experiments show that the proposed method can synchronize with a time that is closer to that of a real-world clock and with higher accuracy than existing methods.