The ‘right to be forgotten’ on the blockchain

Blockchain is an immutable distributed database. It supports traceability and auditability and therefor makes blockchain trustworthy. As outlined in a previous blog post this same immutability may be at odds with the GDPR.

Recently researchers from the University of New South Wales have come up with a solution to remove data from a blockchain without breaking the blockchain’s consistency. Memory Optimised Flexible Blockchain allows users to temporarily store, summarise or remove transactions from the blockchain. The links among blocks, through hash functions, are preserved if blocks are removed from the chain.The remaining trace of data which is its hash can still be used for verification in the future as long as the removed data is stored privately outside the blockchain.

This approach to separate transaction and data flows can run on top of any existing blockchain. Moreover it is also beneficial for the reduction of blockchain storage requirements.

Reference material:

https://www.sciencedirect.com/science/article/pii/S0167739X17329552