## Cryptology ePrint Archive: Report 2020/362

Another Look at CBC Casper Consensus Protocol

Yongge Wang

Abstract: Ethereum Research team has proposed a family of Casper blockchain consensus protocols. It has been shown in the literature that the Casper Friendly Finality Gadget (Casper FFG) cannot achieve liveness property in partially synchronous networks such as the Internet environment. The Correct-by-Construction'' family of Casper blockchain consensus protocols (CBC Casper) has been proposed as a finality gadget for the future Proof-of-Stake (PoS) based Ethereum blockchain. Unfortunately, no satisfactory/constructive finality rules have been proposed for CBC Casper and no satisfactory liveness property has been obtained for CBC Casper. Though it is commonly/widely believed in the community that CBC Casper could not achieve liveness property in asynchronous networks, this paper provides a surprising result by proposing the first CBC Casper protocol that achieves liveness property against $n/3$ Byzantine participants in completely asynchronous networks. Our result is based on Bracha's improved version of the seminal Ben-Or Byzantine Fault Tolerance protocol.

Category / Keywords: cryptographic protocols / Byzantine Fault Tolerance

Date: received 27 Mar 2020, last revised 3 Apr 2020, withdrawn 19 Apr 2020

Contact author: yonwang at uncc edu

Available format(s): (-- withdrawn --)

Short URL: ia.cr/2020/362

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