Blockchain technology is on a collision course with EU privacy law

• David Meyer

Those who have heard of “blockchain” technology generally know it as the underpinning of the Bitcoin virtual currency, but there are myriad organizations planning different kinds of applications for it: executing contracts, modernizing land registries, even providing new systems for identity management. There’s one huge problem on the horizon, though: European privacy law. The bloc’s General Data Protection law, which will come into effect in a few months‘ time, says people must be able to demand that their personal data is rectified or deleted under many circumstances. A blockchain is essentially a growing, shared record of past activity that’s distributed across many computers, and the whole point is that this chain of transactions (or other fragments of information) is in practice unchangeable – this is what ensures the reliability of the information stored in the blockchain.