Contributions to Books:

N. Stifter, A. Judmayer, E. Weippl:
"Revisiting Practical Byzantine Fault Tolerance Through Blockchain Technologies";
in: "Security and Quality in Cyber-Physical Systems Engineering", Springer International Publishing, Switzerland, 2019, ISBN: 978-3-030-25311-0.

English abstract:
The connection between Byzantine fault tolerance and cryptocurrencies, such as Bitcoin, may not be apparent immediately. Byzantine fault tolerance
is intimately linked to engineering and design challenges of developing longrunning and safety-critical technical systems. Its origins can be traced back to
the question of how to deal with faulty sensors in distributed systems, and the
fundamental insight that majority voting schemes may be insufficient to guarantee correctness if arbitrary, or so called Byzantine failures, can occur. However, achieving resilience against Byzantine failures has its price, both in terms
of the redundancy required within a system, as well as the incurred communication overhead. Together with the complexity of correctly implementing Byzantine fault tolerant (BFT) protocols, it may help to explain why BFT systems
have not yet been widely deployed in practice, even though practical designs
exist for almost twenty years. On the other hand, asking anyone about Bitcoin or
blockchain ten years ago would have only raised quizzical looks. Since then, the
ecosphere surrounding blockchain technologies has grown from the pseudonymously published proposal for a peer-to-peer electronic cash system into a multi
billion-dollar industry. At the heart of this success story lies not only the technical innovations presented by Bitcoin, but a colorful and diverse community that
has succeeded in bridging gaps and bringing together various disciplines from
academia and industry alike. Bitcoin reinvigorated interest in the topic of BFT
as it was arguably the first system that achieved a practical form of Byzantine
fault tolerance with a large and changing number of participants. Research into
the fundamental principles and mechanisms behind the underlying blockchain
technology of Bitcoin has since helped advance the field and state of the art regarding BFT protocols. This chapter will outline how these modern blockchain
technologies relate to the field of Byzantine fault tolerance and outline advantages and disadvantages in their design decisions and fundamental assumptions.
Thereby, we highlight that Byzantine fault tolerance should be considered a practical and fundamental building block for modern long-running and safety critical
systems and that the principles, mechanisms, and blockchain technologies themselves could help improve the security and quality of such systems.

blockchain; byzantine fault tolerance; distributed ledger technologies; bitcoin; distributed systems

"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)

Created from the Publication Database of the Vienna University of Technology.