A Proof-of-Trust consensus protocol for enhancing accountability in crowdsourcing services

Jun Zou, Bin Ye, Lie Qu, Yan Wang, Mehmet A. Orgun, Lei Li

Research output: Contribution to journalArticlepeer-review

45 Citations (Scopus)


Incorporating accountability mechanisms in online services requires effective trust management and immutable, traceable source of truth for transaction evidence. The emergence of the blockchain technology brings in high hopes for fulfilling most of those requirements. However, a major challenge is to find a proper consensus protocol that is applicable to the crowdsourcing services in particular and online services in general. Building upon the idea of using blockchain as the underlying technology to enable tracing transactions for service contracts and dispute arbitration, this paper proposes a novel consensus protocol that is suitable for the crowdsourcing as well as the general online service industry. The new consensus protocol is called “Proof-of-Trust” (PoT) consensus; it selects transaction validators based on the service participants’ trust values while leveraging RAFT leader election and Shamir's secret sharing algorithms. The PoT protocol avoids the low throughput and resource intensive pitfalls associated with Bitcoin’s “Proof-of-Work” (PoW) mining, while addressing the scalability issue associated with the traditional Paxos-based and Byzantine Fault Tolerance (BFT)-based algorithms. In addition, it addresses the unfaithful behaviors that cannot be dealt with in the traditional BFT algorithms. The paper demonstrates that our approach can provide a viable accountability solution for the online service industry.

Original languageEnglish
Pages (from-to)429-445
Number of pages17
JournalIEEE Transactions on Services Computing
Issue number3
Early online date5 Apr 2018
Publication statusPublished - Jun 2019


  • Accountability
  • Bitcoin
  • Blockchain
  • Byzantine Agreement
  • Consensus
  • Contracts
  • Crowdsourcing
  • PoS
  • PoT
  • PoW
  • Protocols
  • Scalability

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