Skip to main content

GDPR Compliance for Blockchain Applications: A Guide for European Companies


The General Data Protection Regulation (GDPR) is a comprehensive privacy regulation that governs the collection, processing, and storage of personal data within the European Union (EU) and the European Economic Area (EEA). As a European company building a blockchain application, it is essential to ensure your application complies with GDPR regulations. This documentation will outline key considerations and provide guidance for achieving compliance.

To support our clients in achieving GDPR compliance, we have prepared a guide outlining key considerations and providing guidance for compliance.

Key Considerations

1. Data minimization

Under GDPR, companies must practice data minimization, which means collecting and processing only the data necessary to achieve a specific purpose. Blockchain applications, with their immutability and transparency, can pose challenges to data minimization. Consider the following:

  • Only collect and store necessary data on the blockchain
  • Use off-chain storage for sensitive data, and store only hashes or pointers on the blockchain

2. Identifying data controllers and data processors

GDPR outlines the roles and responsibilities of data controllers and data processors. In the context of a blockchain application:

  • Data controllers determine the purpose and means of processing personal data
  • Data processors process personal data on behalf of the data controllers

Identify and define the roles of all parties involved in your blockchain application, ensuring each party understands their GDPR obligations.

3. Right to erasure (right to be forgotten)

GDPR grants individuals the right to request the deletion of their personal data. Blockchain's immutable nature can complicate this. Consider the following approaches:

  • Store personal data off-chain, keeping only non-identifiable hashes on the blockchain
  • Implement cryptographic techniques, such as zero-knowledge proofs, to obscure personal data on the blockchain

4. Pseudonymization and anonymization

To enhance privacy and meet GDPR requirements, consider using pseudonymization and anonymization techniques in your blockchain application:

  • Pseudonymization: Replace personally identifiable information (PII) with pseudonyms, making it difficult to link data back to an individual
  • Anonymization: Remove or alter PII in a way that makes it impossible to identify individuals

Both techniques can be employed to minimize the risk of data breaches and maintain GDPR compliance.

Under GDPR, user consent is essential for processing personal data. Blockchain applications must ensure:

  • Users give clear, affirmative consent for data collection and processing
  • Consent can be withdrawn at any time
  • Users are informed about the purposes and extent of data processing

Develop a transparent consent management system that allows users to grant, withdraw, or manage their consent easily.

6. Data Protection Impact Assessment (DPIA)

Conduct a DPIA to identify and assess privacy risks associated with your blockchain application. This process includes:

  • Describing the nature, scope, and context of the data processing
  • Assessing the risks to individuals' rights and freedoms
  • Identifying and implementing measures to mitigate these risks

A DPIA is a crucial step in ensuring GDPR compliance and demonstrating your commitment to data protection.

7. Cross border transfers

  • The requirement for appropraite safeguards of transfers outside Europe such as binding contract rules or standard contractual clauses are entirely applicable to permissioned blockchains.


Achieving GDPR compliance for your blockchain application is a complex process, but with careful consideration and implementation of the guidelines outlined above, it is achievable. By adhering to GDPR regulations and implementing the guidelines outlined in this guide, we can foster trust and ensure the privacy and protection of user data within your blockchain application. At SettleMint, we are committed to supporting our clients in achieving GDPR compliance and promoting responsible data management practices.