A Center for Sustainable Cloud Computing

The bitcoin arguably represents the most robust computational structure. However, many computer scientists today believe that the bitcoin protocol is an overkill because it lacks efficiency in the way it processes transactions and suffers from latency. Besides, it is also an energy guzzler. According to an estimate, the bitcoin algorithm consumes as much energy as that used by the Czech Republic and Denmark, and close to that of Austria. The high energy consumption is naturally being criticized because of climate change. Looking at these drawbacks of the bitcoin protocol, there is a growing need to explore more efficient decentralized transaction systems that do not compromise security or reliability.

After extensive research, Professor Rachid Guerraoui and colleagues at EPFL’s School of Computer and Communication Sciences (IC) have proposed a nearly zero-energy alternative to the bitcoin. The system, dubbed Byzantine Reliable Broadcast, represents a paradigm shift in the approach toward cryptocurrencies.

In contrast to the original bitcoin idea of solving the problem of ‘consensus’ to ensure secure transactions, the EPFL researchers work on the premise that there is no need to reach consensus. They demonstrate that it is possible to achieve safe and secure cryptocurrency transactions on a large scale with high energy efficiency. While bitcoin leaves a heavy carbon footprint of 300kg for a single transaction, the system developed by the EPFL team consumes only a few grams.

At the base of the Byzantine Reliable Broadcast is communication and broadcasting. The players need to communicate among each other and that prevents the system from accepting any payment from a malicious player.

Guerraoui and colleagues have already published papers on the theoretical results of the system and its implementation. Their paper “Scalable Byzantine Reliable Broadcast” won the Best Paper Award at DISC 2019 and has already drawn considerable attention from the industry.