*Article* **A Compute and Wait in PoW (CW-PoW) Consensus Algorithm for Preserving Energy Consumption**

**Mostefa Kara 1,\*, Abdelkader Laouid 1, Muath AlShaikh 2, Mohammad Hammoudeh 3, Ahcene Bounceur 4,\*, Reinhardt Euler 4, Abdelfattah Amamra 5 and Brahim Laouid 1**


**Abstract:** Several trusted tasks use consensus algorithms to solve agreemen<sup>t</sup> challenges. Usually, consensus agreements are used to ensure data integrity and reliability in untrusted environments. In many distributed networking fields, the Proof of Work (PoW) consensus algorithm is commonly used. However, the standard PoW mechanism has two main limitations, where the first is the high power consumption and the second is the 51% attack vulnerability. In this paper, we look to improve the PoW consensus protocol by introducing several proof rounds. Any given consensus node should resolve the game of the current round *Roundi* before participating in the next round *Roundi*+1. Any node that resolves the game of *Roundi* can only pass to the next round if a predetermined number of solutions has been found by other nodes. The obtained evaluation results of this technique show significant improvements in terms of energy consumption and robustness against the 51% and Sybil attacks. By fixing the number of processes, we obtained an energy gain rate of 15.63% with five rounds and a gain rate of 19.91% with ten rounds.

**Keywords:** improved PoW consensus algorithms; blockchain; energy consumption; distributed systems; game competition
