[Paper Review] GEEC: Scalable, Efficient, and Consistent Consensus for Blockchains.

Xusheng Chen, Shixiong Zhao+3 more|arXiv (Cornell University)|Aug 7, 2018

Blockchain Technology Applications and Security3 citations

TL;DR

GEEC is a permissioned blockchain protocol that leverages Intel SGX hardware to achieve strong consistency, high efficiency, and strong privacy with only one and a half network round-trips and two P2P broadcasts per block. It provides a provably strongly consistent consensus mechanism while ensuring security and privacy through hardware-enforced isolation.

ABSTRACT

Blockchain technology has the potential to deploy broad decentralized applications, greatly improving their security and reliability. Unfortunately, despite much effort, no existing public blockchain protocol can ensure strong consistency with a high efficiency, while reliability of permissioned blockchain relies on consortium members. We present GEEC, a inital blockchain protocol and its runtime system by leveraging the Intel Software Guard eXtentions (SGX) hardware. GEECachieves privacy and security for permissioned blockchains and leveraging Intel SGX. GEEC can append a block with only one and a half network round-trips and two P2P broadcasts. We carry a proof sketch to show that GEEC is strongly consistent.

Motivation & Objective

• To address the lack of strong consistency and high efficiency in existing public blockchain protocols.
• To enhance reliability and security in permissioned blockchains without relying solely on consortium trust.
• To leverage Intel SGX to enforce privacy and security in consensus execution.
• To design a consensus protocol that minimizes network round-trips and communication overhead.
• To formally prove strong consistency of the proposed protocol.

Proposed method

• Utilizes Intel Software Guard Extensions (SGX) to isolate and protect consensus execution in a hardware-enforced trusted execution environment.
• Designs a consensus protocol that requires only one and a half network round-trips and two P2P broadcasts per block.
• Employs a proof sketch to formally establish strong consistency of the protocol.
• Integrates a runtime system that ensures secure and efficient execution of consensus logic within SGX enclaves.
• Relies on SGX's remote attestation to ensure the integrity and authenticity of the consensus process.

Experimental results

Research questions

• RQ1 Can a blockchain consensus protocol achieve strong consistency while maintaining high efficiency and low communication overhead?
• RQ2 How can hardware-enforced isolation via Intel SGX be leveraged to ensure privacy and security in permissioned blockchains?
• RQ3 What is the minimal network round-trip and broadcast cost required for a strongly consistent consensus protocol?
• RQ4 Can a provably consistent consensus mechanism be designed using trusted execution environments?

Key findings

• GEEC achieves strong consistency through a formal proof sketch, ensuring all nodes agree on the global state.
• The protocol requires only one and a half network round-trips and two P2P broadcasts per block, minimizing latency.
• Security and privacy are enforced via Intel SGX, protecting consensus logic from external and internal threats.
• The runtime system enables efficient execution of consensus within SGX enclaves, ensuring practical performance.