Abstract | ||
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Low transaction throughput and poor scalability are significant issues in public blockchain consensus protocols, such as Bitcoins. Recent research efforts in this direction have proposed shard-based consensus protocols where the key idea is to split the transactions among multiple committees (or shards), which then process these shards or set of transactions in parallel. Such a parallel processing of disjoint sets of transactions or shards by multiple committees significantly improves the overall scalability and transaction throughout of the system. However, one significant research gap is a lack of understanding of the strategic behavior of rational processors within committees in such shard-based consensus protocols. Such an understanding is critical for designing appropriate incentives that will foster cooperation within committees and prevent free-riding. In this paper, we address this research gap by analyzing the behavior of processors using a game-theoretic model, where each processor aims at maximizing its reward at a minimum cost of participating in the protocol. We first analyze the Nash equilibria in an N-player static game model of the sharding protocol. We show that depending on the reward sharing approach employed, processors can potentially increase their payoff by unilaterally behaving in a defective fashion, thus resulting in a social dilemma. In order to overcome this social dilemma, we propose a novel incentive-compatible reward sharing mechanism to promote cooperation among processors. Our numerical results show that achieving a majority of cooperating processors (required to ensure a healthy state of the blockchain network) is easier to achieve with the proposed incentive-compatible reward sharing mechanism than with other reward sharing mechanisms. |
Year | DOI | Venue |
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2018 | 10.1109/ACCESS.2018.2884764 | IEEE ACCESS |
Keywords | DocType | Volume |
Sharding,blockchain,game theory,cooperation,and incentive design | Journal | 6 |
ISSN | Citations | PageRank |
2169-3536 | 2 | 0.37 |
References | Authors | |
0 | 4 |
Name | Order | Citations | PageRank |
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Mohammad Hossein Manshaei | 1 | 786 | 53.69 |
Murtuza Jadliwala | 2 | 266 | 25.26 |
Ananda Maiti | 3 | 43 | 9.63 |
Mahdi Fooladgar | 4 | 2 | 0.37 |