The present disclosure provides a blockchain platform having functionality that enables blockchain nodes to be shared among multiple entities while maintaining security with respect to the blockchain. Blockchain platforms of embodiments include a hash function (also referred to as a chain-code) that enables attributes to be generated and attached to user identifiers, where the attributes associate users with specific entities supported by the blockchain. For shared nodes, the attribute may be utilized, at least in part, to control access permissions to data recorded to the blockchain. Embodiments of blockchain platforms may find particular utility when applied to complex use cases involving multiple entities.