After-Hours Seminar: Foundational Aspects of the Blockchain Consensus
February 12, 2019 | 18h30-20h30
Ecole Polytechnique, Drahi-X Innovation Center
Route de Saclay | Palaiseau, France
Decentralised cryptocurrencies such as Bitcoin have ignited much excitement, not only for their novel realisation of central bank-free financial instruments, but also as an alternative approach for the development of numerous distributed applications in which agreement must be reached without central control and despite misbehaving parties. The soundness and security of these applications, however, hinge on the thorough understanding of the fundamental properties of their underlying blockchain data structure that parties (“miners”) maintain and try to extend by generating “proofs of work”. In this talk we formulate such fundamental properties of the blockchain — “common prefix", "chain quality", "chain growth” — and show how the blockchain consensus differs from the classical problem of consensus in distributed computing and from the consensus in control theory. We analyse the impact of different setups, computational assumptions, and network models on the various properties of the blockchain consensus. We also examine the crucial role of the “proofs of work” for achieving network synchrony on top of unstructured P2P networks.
Registration is free but mandatory, on https://www.epizeuxis.net/afterhours/