# Pastebin TOKCJAu9
If blockchains are used in the processing of personal data, the blockchain application in particular needs to allow implementing the data subject rights as set down in articles 15–18 and 20 of the GDPR. They are about
• the right of access by the data subject (article 15),
• the right to rectification (article 16),
• the right to erasure (‘right to be forgotten’, article 17),
• the right to restriction of processing (article 18) as well as
• the right to data portability (article 20).
Recital 26 of the GPDR includes a statement important in the context of blockchain technology, namely that personal data which have undergone pseudonymisation should still be considered personal data if they can be attributed to a natural person by the use of additional information. Hence, such data are equally subject to the principles of data protection. The GDPR does not apply to data that have been reliably anonymised though.