Date depot: 5 avril 2021 Titre: Blockchains as mean field games Directrice de thèse: Maria POTOP-BUTUCARU (LIP6) Directeur de thèse: Idris KHARROUBI (LPSM) Domaine scientifique: Sciences et technologies de l'information et de la communication Thématique CNRS : Non defini Resumé: Blockchain phenomena is similar to the last century gold rush. Blockchain technologies are publicized as being the technical solution for fully decentralizing activities that were for centuries centralized such as health, administration or banking. Therefore, prominent socio-economical actors all over the world are attracted and ready to invest in these technologies. Despite their large publicity blockchains are far from being a technology ready to be used in critical economical applications and scientists multiply their effort in warning about the risks of using this technology before understanding and fully mastering it. Interestingly, many recent attempts to alarm on vulnerabilities of popular blockchains like Bitcoin are target of defenders brigading. The main challenge of the thesis is to explore in the context of blockchains the recent field of mean field games which have been recently introduced in order to model non-cooperative games with large number of symmetric agents.