Proof of Luck: an Efficient Blockchain Consensus Protocol (1703.05435v1)

Abstract: In the paper, we present designs for multiple blockchain consensus primitives and a novel blockchain system, all based on the use of trusted execution environments (TEEs), such as Intel SGX-enabled CPUs. First, we show how using TEEs for existing proof of work schemes can make mining equitably distributed by preventing the use of ASICs. Next, we extend the design with proof of time and proof of ownership consensus primitives to make mining energy- and time-efficient. Further improving on these designs, we present a blockchain using a proof of luck consensus protocol. Our proof of luck blockchain uses a TEE platform's random number generation to choose a consensus leader, which offers low-latency transaction validation, deterministic confirmation time, negligible energy consumption, and equitably distributed mining. Lastly, we discuss a potential protection against up to a constant number of compromised TEEs.

• The paper introduces TEE-enabled consensus primitives, including proof of luck, to replace traditional energy-intensive proof-of-work models.
• It demonstrates a scalable and low-latency validation process, proposing a 15-second round time for rapid transaction confirmations.
• The study addresses security by mitigating centralization risks and outlines a probabilistic framework that minimizes the chance of a minority takeover.

An Expert Review of "Proof of Luck: An Efficient Blockchain Consensus Protocol"

The paper "Proof of Luck: an Efficient Blockchain Consensus Protocol" introduces an innovative blockchain consensus algorithm that leverages Trusted Execution Environments (TEEs) to address some persistent challenges in blockchain technologies, particularly those based on the proof-of-work (PoW) model. Existing consensus algorithms, like PoW, while robust against certain types of malicious behavior, impose substantial demands on computational resources, consequently leading to significant energy consumption. This paper proposes an alternative that seeks to achieve lower-latency transaction validation and equitable mining distribution with minimal energy footprint.

Key Contributions

The paper makes several novel contributions:

1. TEE-Enabled Consensus Primitives: The research explores three consensus primitives—proof of work, proof of time, and proof of ownership—that are adapted to utilize TEE capabilities. These primitives serve as drop-in replacements for traditional consensus mechanisms.
2. Proof of Luck Protocol: A novel consensus mechanism named "proof of luck" is introduced. This protocol differentiates itself by using TEE platforms' random number generation capabilities to determine consensus leaders, offering low-latency validation, reduced energy consumption, and equal mining opportunities, irrespective of hardware.

Practical and Theoretical Implications

The integration of TEEs, such as Intel's SGX, is pivotal in this work, aiming to resolve several issues inherent in current blockchain architectures. By making the mining process largely independent of computational power, the Proof of Luck protocol promises to mitigate the centralization trends observed in PoW systems, where mining power is typically centralized around entities with access to advanced hardware like ASICs.

• Energy Efficiency: One of the protocol's standout features is its negligible energy requirement compared to traditional PoW. By eliminating the need for continuous computational exertion, the protocol makes blockchain systems more sustainable and accessible to consumer-grade hardware.
• Scalability and Latency: The deterministic approach to transaction validation can substantially reduce block confirmation times. A proposed ROUND TIME of 15 seconds, significantly faster than Bitcoin’s 10-minute interval, can enhance blockchain scalability and make it more suitable for real-time applications.
• Security Considerations: The paper anticipates potential threats arising from compromised TEEs, proposing a mitigation strategy by employing a mechanism that involves the creation of super-blocks made up of multiple TEE-validated proofs of luck, although the paper acknowledges that a full analysis of this approach is reserved for future work.

Analysis of Claims and Future Directions

The authors' assertions regarding blockchain persistency against minority attackers are supported using a probabilistic framework. They demonstrate the exponentially small probability of a minority attacker overtaking a chain dominated by honest participants when using the proof of luck protocol. Moreover, proportional block control derived through fair random sampling might reform decentralized consensus system dynamics by offering an equal opportunity to all participants.

As blockchain technologies continue to evolve, the proposal of integrating TEEs opens promising avenues for enhancing security, efficiency, and accessibility. While the practical deployment of such systems remains contingent upon overcoming potential vulnerabilities like TEE compromises, the proof of luck protocol offers a significant step towards more decentralized and sustainable blockchain systems.

Conclusion

In conclusion, this paper provides a foundational framework that could redefine consensus mechanisms in blockchain technology. By harnessing the capabilities of TEEs, it proposes a more equitable, energy-efficient, and scalable alternative to existing protocols. This work lays the groundwork for potential future extensions that may include sophisticated handling of compromised TEEs and the amalgamation of multiple blockchain systems, an area bristling with opportunity for subsequent research and implementation in the field of secure, decentralized technologies.