• DOI:10.48550/arXiv.2205.00672
• Corpus ID: 248496775

SightSteeple: Agreeing to Disagree with Functional Blockchain Consensus

@article{Ahuja2022SightSteepleAT,
  title={SightSteeple: Agreeing to Disagree with Functional Blockchain Consensus},
  author={Aditya Ahuja},
  journal={ArXiv},
  year={2022},
  volume={abs/2205.00672}
}

• Aditya Ahuja
• Published 2 May 2022
• Computer Science, Mathematics
• ArXiv

Classical and contemporary distributed consensus protocols, may theybeforbinaryagreement,statemachinereplication,orblockchainconsensus,requireallprotocolparticipantsinapeer-to-peersystemtoagreeonexactlythesameinformationaspartoftheconsensuspayload.Althoughthismodelofconsensusisextensivelystudied,andisusefulformostconsensusbaseddecentralizedapplications,itfallsshortofdefiningcorrectdistributedsystemswhichmandateparticipantcredentialbasedprivilegedvisibilityintotheconsensuspayload,throughtheconsensusprotocolitself.Weintroduceanewparadigmfordistributedconsensus,called allows each blockchain protocol participant to agree on some distinct sub-information of the list of transactions, as a function of the credentials of the participant in the blockchain system, instead of agreeing on the entire list of transactions. We motivate two adversary models, one with a standard crash-fault adversary and another with a novel rational-fault adversary, to compromise functional blockchain consensus. We then present two versions of a blockchain protocol called SightSteeple, that achieves functional blockchain consensus in the said fault models. SightSteeple relies on a novel combination of standard blockchain consensus and functional encryption, among other primitives, to achieve its goals of correctness. Finally, we discuss practical uses of functional blockchain consensus based asymmetric distributed ledgers, and motivate off-shoot constructions that can result from this new consensus paradigm.