I don't see the problem. The GDPR allows you to keep what you need. For a blockchain, verification is a need, provided that you need verification. You can easi

I don't see the problem. The GDPR allows you to keep what you need. For a blockchain, verification is a need, provided that you need verification. You can easily argue that you need verification of the most recent 2, 4, 256, 131072 blocks. Some number. All of the blocks for which you have some vaguely reasonable business need to verify, rounded up a bit perhaps. As for really old blocks, do you need those? Why? I realise you can't follow the blockchain all the way back and verify all the way back without them, but if you're a business (or any kind of organisation covered by the GDPR) why do you need to follow the blockchain all the way back?