While the Internet provides enormous opportunities within development of communications and database systems it also endangers the processing of personal data unlawfully. With traditional database structure in focus the responsibility and accountability of said processed personal data was somewhat clear as the General Data Protection Regulation (GDPR) entered the legal framework of the European Union’s member states in May 2018. Blockchain technology being the latest innovation in database structure challenges the applicability of the new regulation by introducing cryptography and a peer-to-peer distributed ledger technology. This thesis is the result of an attempt to analyze the personal data processed in public blockchains, i.e. Bitcoin, and its compliance with certain fundamental data protection rights stipulated in the GDPR such as the right to erasure of personal data. Furthermore, in relation to fundamental data protection rights violations are also subjects of accountability. While the new distributed ledger technology vastly increases the difficulty to determine a target for accountability the thesis also considers the traditional view on databases on which the GDPR was built upon. Thus, the thesis aims to further explore the relation between participants on the innovative blockchain and fundamental personal data protection rights in the GDPR.