In this position paper Bundesblock criticizes that the GDPR does not take blockchain into consideration. I provides recommendations on how to treat blockchain with respect to the GDPR.
The pdf outlines briefly which data fall under the GDPR and what private data is.
It also explains what Data are storedy and used typically in a blockchain and that those data are stored permanently.
According to the position paper the GDPR is a threat to blockchain initiatives in Europe and Germany. Particularly Miner and Nodes might be liable for storing sensitive information.
The paper makes statements about Principles in handling data, the right to e, the right to restrict processing and the right to port personal data.