Consensus Algorithm for a Private Blockchain

In this paper we give an overview of the Blockchain. We explain quickly how it works thanks to the hash function and the distributed architecture. Then come the descriptions of the two most famous consensus algorithms: Proof of Work and Proof of Stake. We also present some security issues for each algorithm. This paper contains a little explanation of others consensus algorithms that are inspired of these two. Finally, a new consensus algorithm for private Blockchain is presented.