By FINTECH Books Contributor, Bartlomiej Klinger Follow: @BartekKlinger One of the most challenging areas of compliance which covers almost all customer-facing activities is the personal data protection. It is a hot topic nowadays. It has been widely discussed in the European Union due to the General Data Protection Regulation which comes into force in May 2018. The new regulation will impact all EU Member States but it will also force the implementation of the most important GDPR rules by non-EU countries which process EU citizens’ personal data and are interested in doing business within the EU. The GDPR, followed by the upcoming ePrivacy regulation, causes anxiety primarily due to extremely high fines: 20 mln EUR or 4% of annual global turnover – whichever proves more. Other worrying aspects of the GDPR are demanding obligations like explicit consents which can be withdrawn at any time, right to be forgotten or ensuring the possibility to transfer own data to another service provider. Is it possible to effectively apply the blockchain technology to support in a cost-effective way any compliance aspect on the personal data protection field? The presented use case shows a possible solution for solving the issue with management of consents to use personal data. Cryptographically secured, tamper-proof, immutable and highly available distributed ledger, based on the blockchain technology seems to be the well-suited solution for the consents management system. Presented solution could also raise regular users’ data privacy awareness and give all of us more control of the way our personal data is used. Companies which will implement the described solutions will be fully compliant with both GDPR and the upcoming ePrivacy regulation. The compliance could be also easily checked by the auditors who, thanks to the nature of the blockchain technology, will get a transparent, reliable and auditable source of reports.