A Sustainable Reward Mechanism for Block Mining in PoW-Based Blockchain

Blockchain brings a peer-to-peer transaction solution without a trusted third authority over the peer-to-peer network. Proof-of-work (PoW), also called `mining', incents some peers (called miners)to compete for the right of block generation by rewarding a certain mount of cryptocurrency. Hence, PoW undertakes the cryptocurrency creation and block generation in a blockchain based transaction system (BTS). However, in a BTS, the block mining reward (BMR)will be terminated after that the regulated quantity of currency have been minted. Although the voluntarily paid transaction fee is allowed to support BMR, the stable reward for block mining is no longer guaranteed, and which inevitably destroys the sustainability of BTS. In this work, we propose a sustainable reward mechanism (SRM)for block mining in BTS. Specifically, SRM introduces a mandatory transaction fee mechanism with dedicated fee rate determination algorithm. An on-chain public account (PA), which is trust-free but security-provable, is set to collect the dynamic transaction fees. With transaction fee collection under adaptive fee rate setting, PA provides the steady BMR, thus makes blockchain sustainable when the currency creation purposed BMR has been terminated. Numerical results are presented to demonstrate the effectiveness of SRM.