Abstract: Over the last years, blockchains have developed into a mainstream technology that entire industry sectors are talking about. The latest generation even supports smart contracts – programs that are executed by all participants and that may govern everything from simple transactions to the setup of organisations. Beyond the hype, however, we find that there is little deployment beyond the two most prominent examples, Bitcoin and Ethereum. 

In this talk, we are going to explore some of the reasons. In particular, we show that the P2P networks that underlie blockchains impact their functionality in decisive ways. We look at dependability and abortion of transactions, both of which are crucial for enterprises, and we inspect the network structure and its influence on transaction execution. We present some early numbers from more than 2,500 scans of a blockchain network.  Finally, we discuss some research directions that could prove fruitful in a number of systems, blockchains or beyond.

Bio: Ralph Holz is Lecturer in Networks and Security at the School of IT at the University of Sydney, where he leads the Node for Cybersecurity in the Human-Centred Technologies cluster. He works closely with Data61|CSIRO, Australia’s prime innovation body, and is a Visiting Fellow at the University of New South Wales.

Ralph’s primary research interest is empirical security, in particular measuring the deployment properties of critical infrastructure (including blockchains) and the effects and causes of network and routing incidents. He led the research efforts that culminated in the world’s first large-scale, long- term analysis of the deployment of the Web Public Key Infrastructure.  Most recently, he has turned his attention to analysing the security and dependability of blockchain networks.

Ralph received his PhD from Technical University of Munich (TUM) in May 2014.