Design principle DP3: GDPR conformance via off-chain storage and ZKPs
Conform to GDPR by storing actual documents off-chain (only hashes on-chain) and using zero-knowledge proofs and user-held identity so that data ownership and access control are ensured.
Source paper
This design principle is proposed by Designing GDPR Compliant Credential Verification Using Blockchain: A Design Science Research Approach (Janne Parkkila, AKM Bahalul Haque, Jaakko Vuolasto, Anastasiia Gurzhii, Sami Hyrynsalmi, Najmul Islam, 2024).