Exclusive ownership of data units, such as monetary units, is transferred by inputting a request from a transferor, to transfer to a transferee at least a designated one of the data units, said request including an identifier of the transferor, an identifier of the designated data unit, and an identifier of a transferee. The identifier of the transferor is verified and the absence of any other request to transfer the designated data unit during an update period is confirmed. A designation of ownership of the designated data unit is then changed from the transferor to the transferee in a ledger, which is comprised of a group of subledgers, each configured as a blockchain. Ownership is thereby processed per-unit instead of per-account.