International Association
for Cryptologic Research

@inproceedings{crypto-2017-28222,
  title={The Bitcoin Backbone Protocol with Chains of Variable Difficulty},
  booktitle={CRYPTO},
  publisher={Springer},
  pages={291-323},
  doi={10.1007/978-3-319-63688-7_10},
  author={Juan A. Garay and Aggelos Kiayias and Nikos Leonardos},
  year=2017
}