The present disclosure provides an approach for a blockchain system in which (a) data of past transactions can be removed from the storage of network nodes based on node permissions, and (b) in which data can be made invisible to users based on user-specific or group-specific permissions. The blockchain system stores cryptographic proofs of data on an immutable ledger. The data itself is maintained within the blockchain system such that it can be partially or fully removed, while maintaining the integrity of the ledger.