  Blockchains combine other technologies, such as cryptography, networking, and
incentive mechanisms, to enable the creation, validation, and recording of
transactions between participating nodes. A consensus algorithm is used in a
blockchain system to determine the shared state among distributed nodes. An
important component underlying any blockchain-based system is its consensus
mechanism, which principally determines the performance and security of the
overall system. As the nature of peer-to- peer(P2P) networks is open and
dynamic, the security risk within that environment is greatly increased mostly
because nodes can join and leave the network at will. Thus, it is important to
have a system that can check against malicious behaviour. In this work, we
propose a reputation-based consensus mechanism for blockchain-based systems,
Proof-of-Reputation(PoR) where the nodes with the highest reputation values
eventually become part of a consensus group that determines the state of the
blockchain.
