Toward EU-GDPR Compliant Blockchains with Intentional Forking

With the introduction of the European Union’s General Data Protection Regulation service, providers have to make various adjustments to their business processes and software. Under the GDPR users can, at any time, request that their data is deleted when they no longer use a service or have their data rectified when the service provider stores inaccurate or false data. However, blockchains or distributed ledgers all have in common that they are “append only”. Also every modification to historic data can be immediately detected through the now invalidated hash values stored in every block. In this chapter, we propose a transaction model based upon our previously devised dispute mechanism to cope with the GDPR requirements of deletion and rectification. By introducing the longest-chain-rule into a BFT-PoS Blockchain, we can achieve a validator approved intentional fork to modify previous data.