Paper 2024/452

Modeling Mobile Crash in Byzantine Consensus

Hans Schmiedel, Monash University
Runchao Han, BabylonChain Inc.
Qiang Tang, University of Sydney
Ron Steinfeld, Monash University
Jiangshan Yu, University of Sydney

Targeted Denial-of-Service (DoS) attacks have been a practical concern for permissionless blockchains. Potential solutions, such as random sampling, are adopted by blockchains. However, the associated security guarantees have only been informally discussed in prior work. This is due to the fact that existing adversary models are either not fully capturing this attack or giving up certain design choices (as in the sleepy model or asynchronous network model), or too strong to be practical (as in the mobile Byzantine adversary model). This paper provides theoretical foundations and desired properties for consensus protocols that resist against targeted DoS attacks. In particular, we define the Mobile Crash Adaptive Byzantine (MCAB) model to capture such an attack. In addition, we identify and formalize two properties for consensus protocols under the MCAB model, and analyze their trade-offs. As case studies, we prove that Ouroboros Praos and Algorand are secure in our MCAB model, giving the first formal proofs supporting their security guarantee against targeted DoS attacks, which were previously only informally discussed. We also illustrate an application of our properties to secure a streamlined BFT protocol, chained Hotstuff, against targeted DoS attacks.

Available format(s)
Publication info
Published elsewhere. 37th IEEE Computer Security Foundations Symposium
ConsensusBlockchainDistributed systems
Contact author(s)
hans schmiedel @ monash edu
me @ runchao rocks
qiang tang @ sydney edu au
ron steinfeld @ monash edu
jiangshan yu @ sydney edu au
2024-05-13: revised
2024-03-16: received
See all versions
Short URL
Creative Commons Attribution-NonCommercial


      author = {Hans Schmiedel and Runchao Han and Qiang Tang and Ron Steinfeld and Jiangshan Yu},
      title = {Modeling Mobile Crash in Byzantine Consensus},
      howpublished = {Cryptology ePrint Archive, Paper 2024/452},
      year = {2024},
      note = {\url{}},
      url = {}
Note: In order to protect the privacy of readers, does not use cookies or embedded third party content.