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“Nonlinear Feedback Control and Stability Analysis of a Proof-of-Work Blockchain”

Authors: Geir Hovland and Jan Kucera,
Affiliation: University of Agder and Bismuth Foundation
Reference: 2017, Vol 38, No 4, pp. 157-168.

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Keywords: Nonlinear, control system, blockchain, feedback, stability, disturbance rejection

Abstract: In this paper a novel feedback controller and stability analysis of a blockchain implementation is developed by using a control engineering perspective. The controller output equals the difficulty adjustment in the mining process while the feedback variable is the average block time over a certain time period. The computational power (hash rate) of the miners is considered a disturbance in the model. The developed controller is tested against a simulation model with constant disturbance, step and ramp responses as well as with a high-frequency sinusoidal disturbance. Stability and a fast response is demonstrated in all these cases with a controller which adjusts it's output at every new block. Finally the performance of the controller is implemented and demonstrated on a testnet with a constant hash rate as well as on the mainnet of a public open source blockchain project.

PDF PDF (2733 Kb)        DOI: 10.4173/mic.2017.4.1

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  title={{Nonlinear Feedback Control and Stability Analysis of a Proof-of-Work Blockchain}},
  author={Hovland, Geir and Kucera, Jan},
  journal={Modeling, Identification and Control},
  publisher={Norwegian Society of Automatic Control}


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