A set of transaction handling computing elements comprise a network core that receive and process transaction requests into an append-only immutable chain of data blocks, wherein a data block is a collection of transactions, and wherein an Unspent Transaction Output (UTXO) data structure supporting the immutable chain of data blocks is an output from a finalized transaction. Typically, the UTXO data structure consists essentially of an address and a value. In this approach, at least one UTXO data structure is configured to include information either in addition to or in lieu of the address and value, thereby defining a Transaction Output (TXO). A TXO may have a variety of types, and one type includes an attribute that encodes data. In response to receipt of a request to process a transaction, the set of transaction handling computing elements are executed to process the transaction into a block using at least the information in the TXO.