On Transition between PoW and PoS

This article is focused on the area of energy efficiency of cryptocurrencies. Nowadays, nearly two thirds of all cryptocurrencies use Proof of Work (PoW) consensus algorithm to add new blocks to blockchain network. The energy sustainability of whole networks using PoW algorithm is very doubtful. Furthermore, we can see that lots of cryptocurrencies are trying to implement and move to more efficient consensus algorithms like Proof of Stake (PoS). Therefore, in this article we present three potential scenarios to perform transition between PoW and PoS.