US Patent 12095859 Malleability of transactions for inclusion in a blockchain

A method of recording a target transaction in a blockchain, comprising: obtaining an updated version of the target transaction, being updated relative to a pre-existing first version; and instead of the first version, sending the updated version to be propagated through a network of nodes to be recorded in the blockchain. The target transaction comprises an input comprising an unlocking script and a pointer to an output of a first transaction, the output of the first transaction comprising a locking script specifying a plurality of alternative conditions for unlocking that output. The unlocking script of the first version of the target transaction is configured to unlock the first output of the first transaction based on a first of said alternative conditions, and the unlocking script of the updated version is configured to unlock it based on a second one of said alternative conditions.