Title
Proof-of-Prestige: A Useful Work Reward System for Unverifiable Tasks
Abstract
AbstractAs cryptographic tokens and altcoins are increasingly being built to serve as utility tokens, the notion of useful work consensus protocols is becoming ever more important. With useful work consensus protocols, users get rewards after they have carried out some specific tasks useful for the network. While in some cases the proof of some utility or service can be provided, the majority of tasks are impossible to verify reliably. To deal with such cases, we design “Proof-of-Prestige” (PoP)—a reward system that can run directly on Proof-of-Stake (PoS) blockchains or as a smart contract on top of Proof-of-Work (PoW) blockchains. PoP introduces “prestige,” which is a volatile resource that, in contrast to coins, regenerates over time. Prestige can be gained by performing useful work, spent when benefiting from services, and directly translates to users minting power. Our scheme allows us to reliably reward decentralized workers while keeping the system free for the end-users. PoP is resistant against Sybil and collusion attacks and can be used with a vast range of unverifiable tasks. We build a simulator to assess the cryptoeconomic behavior of the system and deploy a full prototype of a content dissemination platform rewarding its participants. We implement the blockchain component on both Ethereum (PoW) and Cosmos (PoS), provide a mobile application, and connect it with our scheme with a negligible memory footprint. Finally, we adapt a fair exchange protocol allowing us to atomically exchange files for rewards also in scenarios where not all the parties have Internet connectivity. Our evaluation shows that even for large Ethereum traces, PoP introduces sub-millisecond computational overhead for miners in Cosmos and less than 0.013$ smart contract invocation cost for users in Ethereum.
Year
DOI
Venue
2021
10.1145/3419483
ACM Transactions on Internet Technology
Keywords
DocType
Volume
Blockchain, security and privacy, network security
Journal
21
Issue
ISSN
Citations 
2
1533-5399
0
PageRank 
References 
Authors
0.34
0
6
Name
Order
Citations
PageRank
Michal Król100.34
Alberto Sonnino2221.94
Mustafa Al-Bassam311.37
Argyrios G. Tasiopoulos4234.35
Etienne Riviere538625.93
Ioannis Psaras694354.27