Arthur Gervais

"On the Security and Scalability of Proof of Work Blockchains"

( MPI-SWS talk in Kooperation mit dem Fachbereich Informatik)

The security properties of blockchain technology allow for the shifting of trust assumptions, e.g., to remove trusted third parties; they, however, create new challenges for security and scalability, which have not yet been fully understood and that we investigate in this talk. The blockchain’s security, for example, affects the ability of participants to exchange monetary value or to participate in the network communication and the consensus process.
Our first contribution provides a quantitative framework to objectively compare the security and performance characteristics of Proof of Work-based blockchains under adversaries with optimal strategies. Our work allows us to increase Bitcoin’s transaction throughput by a factor of ten, given only one parameter change and without deteriorating the security of the underlying blockchain. In our second contribution, we highlight previously unconsidered impacts of the PoW blockchain’s scalability on its security and propose design modifications that are now implemented in the primary Bitcoin client. Because blockchain technology is still in its infancy, we conclude the talk with an outline of future work towards an open, scalable, privacy-preserving and decentralized blockchain.

Bio: Arthur Gervais's research interests revolve around the security and privacy of blockchain technology, and he also worked on web privacy. He just defended in December 2016 his Ph.D. in the Institute of Information Security at ETH Zürich. During his Ph.D., he performed a 3-months internship at Intel Labs, Oregon, working on blockchain technology. He obtained his Master degrees from KTH Stockholm (Sweden) and Aalto University (Finland) in 2012. Furthermore, he holds a diplôme d'ingénieur from INSA de Lyon (France) from 2012. His Master's thesis was on the security of industrial control systems (SCADA).