Fair Peer-to-Peer Content Delivery via Blockchain

TL;DR

This paper introduces blockchain-based solutions for fair peer-to-peer content delivery, ensuring fair rewards for deliverers and fair treatment for consumers and providers, with proven efficiency and practical implementation.

Contribution

It presents the first expressive, minimalist security solutions for p2p content delivery, with two protocols (FairDownload and FairStream) guaranteeing fairness even under collusion.

Findings

Guarantee delivery fairness proportional to in-time delivery

Achieve asymptotically optimal on-chain costs

Prototype implementation on Ethereum demonstrates practicality

Abstract

Peer-to-peer (p2p) content delivery is promising to provide benefits like cost-saving and scalable peak-demand handling in comparison with conventional content delivery networks (CDNs) and complement the decentralized storage networks such as Filecoin. However, reliable p2p delivery requires proper enforcement of delivery fairness, i.e., the deliverers should be rewarded according to their in-time delivery. Unfortunately, most existing studies on delivery fairness are based on non-cooperative game-theoretic assumptions that are arguably unrealistic in the ad-hoc p2p setting. We for the first time put forth the expressive yet still minimalist securities for p2p content delivery, and give two efficient solutions FairDownload and FairStream via the blockchain for p2p downloading and p2p streaming scenarios, respectively. Our designs not only guarantee delivery fairness to ensure deliverers be paid (nearly) proportional to his in-time delivery, but also ensure the content consumers and content providers to be fairly treated. The fairness of each party can be guaranteed when the other two parties collude to arbitrarily misbehave. Moreover, the systems are efficient in the sense of attaining asymptotically optimal on-chain costs and optimal deliverer communication. We implement the protocols to build the prototype systems atop the Ethereum Ropsten network. Extensive experiments done in LAN and WAN settings showcase their high practicality.