Proposal of Fair Proof-of-Work System Based on Rating of User’s Computing Power

Bitcoin has utilized Proof-of-Work(PoW), which prevents double-spend attack in the distributed network. PoW is a consensus protocol that depends on a computing power, therefore it is highly difficult for malicious nodes to attack. However, emerging a group called mining pool encourage the centralization of computing power. This may make it easy to tamper with a distributed ledger called Blockchain of Bitcoin.In this paper, we propose the new protocol which evaluates computing power for each nodes and adjusts difficulty of generating a block based on the evaluation. This gives an equal opportunity for successful mining. Furthermore, reward for user's incentive is also adjusted based on the evaluation.