These are the slides (in english) of my talk I gave (in french) at University Paris VII on january 12th 2017.
Videos in two parts are available here : https://bitcoin.fr/video-paiements-securises-et-non-securises-sur-une-blockchain-1ere-partie/
and there :
In the second part, I presented my article I've recently written with Ricardo Perez-Marco. It should be available soon on arxiv.
For more informations see :