Design principle DP: Principles for designing data-protection-compliant (forgetting) blockchains

The derived guidance for data-protection-compliant blockchains includes: combine an existing technique (state pruning) with a custom function to delete logs and other traces while enabling logging of predefined transactions in the persistent EVM state; keep durable data in the smart-contract state (via explicit logging) rather than in transactions, since transactions are transient; because the original genesis block no longer exists after deletion, bootstrap new or resynchronizing nodes from a recent block obtained and cross-checked from multiple trusted sources; set the data-deletion time to a reasonably long period (e.g., seven days) to accommodate node downtime; and restrict the approach to permissioned/restricted environments where financial and legal incentives (e.g., auditing) discourage participants from archiving deleted data, since network-wide deletion cannot be technically enforced.

Source paper

This design principle is proposed by Design of a forgetting blockchain: A possible way to accomplish GDPR compatibility (Simon Farshid, Andreas Reitz, 2019).

Citations

[1] Simon Farshid, Andreas Reitz. Design of a forgetting blockchain: A possible way to accomplish GDPR compatibility. HICSS 52 (2019). https://hdl.handle.net/10125/59571 (opens in a new tab) [2] Source document: Design of a forgetting blockchain.pdf