Granted Patent B2

US 12,530,680 · App. 18/199,316 · Granted Jan 20, 2026

Inventor: Gavin Allen (London, GB)

Assignee: NCHAIN LICENSING AG

G06Q20/3825G06F21/645G06Q20/0658G06Q20/10G06Q20/3672G06Q20/3674G06Q20/3829G06Q20/401H04L9/0637H04L9/3247H04L63/0421G06Q20/389G06Q2220/00H04L9/50H04L2209/56

Abstract

Claims (38)

1 . A method of controlling a transfer of an asset via a blockchain network, the method comprising:

finding, by a computing agent, an anchor transaction on a blockchain on the blockchain network that is an original issuance transaction for the asset, wherein the anchor transaction includes an unspent transaction output (UTXO) associated with the asset and locked by a locking script that includes a redeem script hash;

traversing, by the computing agent, a chain of transactions on the blockchain from the anchor transaction by iteratively analyzing subsequent transactions to identify a current UTXO set, wherein the current UTXO set represents a current ownership state of the asset;

generating, by the computing agent, an incomplete transaction to transfer control of the asset to a current holder identified by the current UTXO set, incomplete transaction comprising:

an input referencing an UTXO from the current UTXO set locked by the redeem script hash, wherein the incomplete transaction lacks a cryptographic signature of the current holder needed to unlock the redeem script hash of the input of the incomplete transaction;

an output configured with a signature type that allows the current holder to modify the output; and

extracting, by the computing agent, a notification address embedded within an unlocking script from a prior transaction of the chain of transactions, wherein the notification address is an identifier previously provided by the current holder to subscribe to an off-chain notification channel;

transmitting, by the computing agent, the incomplete transaction to the notification address over an off-chain notification channel to the current holder to receive the incomplete transaction;

responsive to transmitting the incomplete transaction, receiving, by the computing agent, a completed transaction via the off-chain notification channel from the current holder, wherein the completed transaction is formed by:

adding to the input of the incomplete transaction the cryptographic signature that unlocks the redeem script hash of that input; and

modifying the output of the incomplete transaction to specify a recipient address;

submitting, by the computing agent, the completed transaction to the blockchain network for validation verifying that the cryptographic signature corresponds to a private key of the current holder.

2 . The method of claim 1 , wherein traversing the chain of transactions comprises analyzing all spends of assets associated with transactions in the chain, starting from the anchor transaction to identify the current UTXO set representing the current ownership state of the asset.

3 . The method of claim 1 , wherein the off-chain notification channel comprises a broadcast channel monitored by the current holder to receive the incomplete transaction.

4 . The method of claim 1 , further comprising, upon sale or other transfer of the asset, embedding, by a new asset holder, a notification address into a sale transaction.

5 . The method of claim 4 , wherein transmission of a notification to the notification address is triggered by an event.

6 . The method of claim 5 , wherein the event is specified in a smart contract.

7 . The method of claim 5 , wherein the notification comprises the incomplete transaction.

8 . The method of claim 1 , further comprising on-selling a proportion of the asset by:

capturing a notification address for a purchaser;

creating a re-sell transaction template;

counter-signing of the re-sell transaction by an asset issuer; and

submitting the re-sell transaction template to the blockchain network for validation and inclusion.

9 . A system comprising:

at least one computing agent performing as a node on a blockchain network, the computing agent comprising:

at least one processor; and

memory comprising computer-executable instructions that, as a result of execution by the at least one processor, cause the at least one computing agent to:

find an anchor transaction on a blockchain on the blockchain network that is an original issuance transaction for the asset, wherein the anchor transaction includes an unspent transaction output (UTXO) associated with the asset and that is locked by a locking script that includes a redeem script hash;

traverse a chain of transactions on the blockchain network from the anchor transaction by iteratively analyzing subsequent transactions to identify a current UTXO set, wherein the current UTXO set represents a current ownership state of the asset;

generate an incomplete transaction to transfer control of the asset to a current holder identified by the current UTXO set, the incomplete transaction comprising:

an input referencing an UTXO from the current UTXO set locked by the redeem script hash, wherein the incomplete transaction lacks a cryptographic signature of the current holder needed to unlock the redeem script hash of the input of the incomplete transaction;

an output configured with a signature type that allows the current holder to modify the output; and

extract a notification address embedded within an unlocking script from a prior transaction of the chain of transactions, wherein the notification address is an identifier previously provided by the current holder to subscribe to an off-chain notification channel;

transmit the incomplete transaction to the notification address over an off-chain notification channel to the current holder to receive the incomplete transaction;

responsive to transmitting the incomplete transaction, receive a completed transaction via the off-chain notification channel from the current holder, wherein the completed transaction is formed by:

adding to the input of the incomplete transaction the cryptographic signature that unlocks the redeem script hash of that input; and

modifying the output of the incomplete transaction to specify a recipient address;

submit the completed transaction to the blockchain network for validation verifying that the cryptographic signature corresponds to a private key of the current holder.

Assignments (3)

Priority Claims (2)

Continuity (2)

References Cited (57)