We use the UTXO model and as a result our transactions are structurally sim- ilar to Bitcoin transactions: they have inputs, outputs and signatures. Unlike Bitcoin, Corda database rows can contain arbitrary data, not just a value field. Because the data consumed and added by transactions is not necessarily a set of key/value pairs, we don’t talk about rows but rather states. Like Bitcoin, Corda states are associated with bytecode programs that must accept a transaction for it to be valid, but unlike Bitcoin, a transaction must satisfy the programs for both the input and output states at once. Issuance transactions may append new states to the database without consuming any existing states but unlike in Bitcoin these transactions are not special and may be created at any time, by anyone