Title
Compounding of Wealth in Proof-of-Stake Cryptocurrencies.
Abstract
Proof-of-stake (PoS) is a promising approach for designing efficient blockchains, where block proposers are randomly chosen with probability proportional to their stake. A primary concern in PoS systems is the "rich getting richer" effect, whereby wealthier nodes are more likely to get elected, and hence reap the block reward, making them even wealthier. In this paper, we introduce the notion of equitability, which quantifies how much a proposer can amplify her stake compared to her initial investment. Even with everyone following protocol (i.e., honest behavior), we show that existing methods of allocating block rewards lead to poor equitability, as does initializing systems with small stake pools and/or large rewards relative to the stake pool. We identify a geometric reward function, which we prove is maximally equitable over all choices of reward functions under honest behavior and bound the deviation for strategic actions; the proofs involve the study of optimization problems and stochastic dominances of Polya urn processes. These results allow us to provide a systematic framework to choose the parameters of a practical incentive system for PoS cryptocurrencies.
Year
DOI
Venue
2018
10.1007/978-3-030-32101-7_3
Lecture Notes in Computer Science
Keywords
Field
DocType
Proof-of-stake,Cryptocurrencies,Random processes
Mathematical economics,Incentive,Proof-of-stake,Computer security,Computer science,Mathematical proof,Initialization,Phenomenon,Cryptocurrency,Optimization problem
Journal
Volume
ISSN
Citations 
11598
0302-9743
2
PageRank 
References 
Authors
0.35
7
6
Name
Order
Citations
PageRank
Giulia C. Fanti114018.95
Leonid Kogan28611.82
Sewoong Oh384360.50
Kathleen Ruan420.35
Viswanath, P.51330179.87
Gerui Wang620.35