Proof-of-Prestige: A Useful Work Reward System for Unverifiable Tasks
This addresses the challenge of incentivizing useful work in utility token systems where tasks cannot be verified, which is incremental as it builds on existing Proof-of-Stake blockchains.
The authors tackled the problem of rewarding users for completing unverifiable tasks in blockchain networks by designing Proof-of-Prestige (PoP), a system that uses a volatile prestige resource to translate useful work into minting power, and they demonstrated its resistance to attacks and cryptoeconomic behavior through simulations.
As cryptographic tokens and altcoins are increasingly being built to serve as utility tokens, the notion of useful work consensus protocols, as opposed to number-crunching PoW consensus, is becoming ever more important. In such contexts, users get rewards from the network after they have carried out some specific task useful for the network. While in some cases the proof of some utility or service can be proved, the majority of tasks are impossible to verify. In order to deal with such cases, we design Proof-of-Prestige (PoP) - a reward system that can run on top of Proof-of-Stake blockchains. PoP introduces prestige which is a volatile resource and, 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. PoP is resistant against Sybil and Collude attacks and can be used to reward workers for completing unverifiable tasks, while keeping the system free for the end-users. We use two exemplar use-cases to showcase the usefulness of PoP and we build a simulator to assess the cryptoeconomic behaviour of the system in terms of prestige transfer between nodes.