The Fundamental Right to Data Protection of Blockchain Users seen through the Applicability of the GDPR

The aim of this chapter is to highlight the different issues that one faces when trying to ensure the fundamental right to data protection of blockchain users. The provisions of the General Data Protection Regulation are used as an example of the difficulties. Here, two principal issues are addressed: issues regarding the addressees of the General Data Protection Regulation's provisions and issues regarding the qualification and treatment of data available on permissionless and permissioned blockchains. Finally, this article highlights the consequences that these uncertainties may have on the protection of users’ fundamental rights and the necessity to ensure legal certainty through additional guidance from the European legislator or upcoming case-law.