Immutability and Decentralized Storage: An Analysis of Emerging Threats

The widespread adoption of the new generation of decentralised architectures, leveraged by blockchain and decentralised file storage (DFS) systems, enables a myriad of new applications and opportunities. Nevertheless, their remarkable features, namely auditability, availability and, among all, immutability, do not come without a cost. In this article, we examine blockchain and the most widely used DFS systems and discuss their main challenges and opportunities, with special regard to their immutability and its impact on their GDPR compliance. A description of current and prospective threats is also provided, along with an analysis of the features that each threat exploits. In addition, we discuss several measures to address the identified threats, and we provide a fertile common ground for further research.