Interface course
Mathematics behind Blockchain
From Monday 30th September 2019 to Wednesday 2nd October 2019

The « blockchain» technology appeared with the « Bitcoin » crypto-currency in 2008, whose principles are described in the founding article of Satoshi Nakamoto (Nakamoto). This breakthrough innovation was seen as an opportunity to revisit the relationship of trust in digital services, first in the financial sector and then in different business verticals of the industry. Today, the initial model has generated a diversity of « blockchain » technologies as well as a wide variety of use cases that are no longer confined to cryptocurrencies. This diversity opens up new subjects of investigation at the crossroads of mathematics, computer science and society’s digital transformation.

During the 3 days of this session of the Interface programme, academics and industry will meet to share a common understanding of these « blockchain » technologies, starting from basic concepts to go to advanced cryptographic primitives that allow to manage the confidentiality of data in particular in a distributed environment. The main objective is to discuss mathematical issues and techniques specific to trust management in a distributed environment, based in particular on industrial use cases (identity, energy, internet of things, etc.).

Keywords: authentication, personal identity management in a distributed environment, associated protocols, delegation, case of the Internet of Things, data protection and cyber-security in the context of blockchain applied to specific use cases, Proof-of-work, Proof-of-Stake, hard/soft fork, Practical Byzantine Fault Tolerant, Proof-of-Elapsed-Time. ​​

September 30 (morning)
Blockchain technologies: what are we talking about?
Speaker: Aline Gouget
Cohabitation of different blockchain technologies and smart contracts
Speaker: Julien Bringer

Exchanges: Questions & feedback on the main topics of interest

September 30 (afternoon)
Use case: Authentication, Identification Access control & blockchain
Speaker: Sophie Dramé-Maigné
Digital identity & blockchain
Speaker: Laurent Castillo

​Exchanges & small group discussions Information sharing between the different workshops

October 1 (morning)
Data confidentiality, Anonymity
Some cryptographic techniques for managing confidentiality in blockchains
Speaker: Daniel Augot
Cryptocurrencies and anonymity
Speaker: Jacques Patarin

October 1 (afternoon)
Use case: data management
Presentation: EDF (to be confirmed)
Workshops: Industrial stakeholders data managers –

Exchanges & small group discussions Information sharing between the different workshops

October 2 (morning)
The question of trust
The question of trust, especially in a blockchain and its ecosystem; is a mathematical formalisation possible?
Speaker: Louis Granboulan
The blockchain in the event of a cryptographic disaster: some scenarios
Speaker: Louis Goubin

October 2 (afternoon)
The choice of consensus protocol
Speaker: Georg Fuchsbauer
Energy optimization of consensus protocols
Speaker: Philippe Jacquet
Workshops: introduction on the security of consensus protocols in a public or private Blockchain environment driven by Aline Gouget and followed by exchanges & discussions in small groups – Informationsharing between the different workshops