A TorPath to TorCoin: Proof-of-Bandwidth Altcoins for Compensating Relays
Mainak Ghosh, Miles Richardson, Bryan Ford, Rob Jansen · 2014
Abstract. The Tor network relies on volunteer relay operators for re-lay bandwidth, which may limit its growth and scaling potential. We propose an incentive scheme for Tor relying on two novel concepts. We introduce TorCoin, an “altcoin ” that uses the Bitcoin protocol to re-ward relays for contributing bandwidth. Relays “mine ” TorCoins, then sell them for cash on any existing altcoin exchange. To verify that a given TorCoin represents actual bandwidth transferred, we introduce TorPath, a decentralized protocol for forming Tor circuits such that each circuit is privately-addressable but publicly verifiable. Each circuit’s participants may then collectively mine a limited number of TorCoins, in proportion to the end-to-end transmission goodput they measure on that circuit. 1