Bonded Mining: Difficulty Adjustment by Miner Commitment

  • George BissiasEmail author
  • David Thibodeau
  • Brian N. Levine
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11737)


Proof-of-work blockchains must implement a difficulty adjustment algorithm (DAA) in order to maintain a consistent inter-arrival time between blocks. Conventional DAAs are essentially feedback controllers, and as such, they are inherently reactive. This approach leaves them susceptible to manipulation and often causes them to either under- or over-correct. We present Bonded Mining, a proactive DAA that works by collecting hash rate commitments secured by bond from miners. The difficulty is set directly from the commitments and the bond is used to penalize miners who deviate from their commitment. We devise a statistical test that is capable of detecting hash rate deviations by utilizing only on-blockchain data. The test is sensitive enough to detect a variety of deviations from commitments, while almost never misclassifying honest miners. We demonstrate in simulation that, under reasonable assumptions, Bonded Mining is more effective at maintaining a target block time than the Bitcoin Cash DAA, one of the newest and most dynamic DAAs currently deployed. In this preliminary work, the lowest hash rate miner our approach supports is 1% of the total and we directly consider only two types of fundamental attacks. Future work will address these limitations.


Difficulty adjustment Protocols Cryptocurrencies 


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • George Bissias
    • 1
    Email author
  • David Thibodeau
    • 2
  • Brian N. Levine
    • 1
  1. 1.College of Information and Computer Sciences, UMass AmherstAmherstUSA
  2. 2.Florida Department of CorrectionsTallahasseeUSA

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