The chapter focuses, in the area of property and security rights, on the interface between the virtual and transnational dimension of transactions on the blockchain on one hand and the “real” world of compulsory and public policy rules applying on a given territory and on given property on the other. The author takes the perspective of a continental lawyer analyzing the validity of transactions, the validity and integrity of the property title electronically created and transferred. In doing so, he relies not only on the traditional legal tools but also on the most recent legislative initiatives, especially in France, introducing a legal framework encompassing new ways of transferring property (based on blockchain technologies) and new titles (e.g., tokens in the context of initial coin offerings). Through this analysis, the core issue is to determine whether these new transactions and these new property titles can be effective, in a national and international context. The author raises questions and concerns about the actual legal uncertainty and the best (local and global) regulatory responses to the technological challenges.