Method and system for settling a blockchain transaction

A computer server for settling an asset transaction in which a first asset is exchanged for a second asset,

• which first asset is registered as an association with a specific first blockchain asset on a digitally and electronically accessed blockchain-based ledger,
• which ledger is arranged to keep track of blockchain transactions concerning the blockchain asset in question from senders to specified blockchain asset addresses, which blockchain transactions are signed using a respective private cryptographic key belonging to the sender in question,
• which association is arranged so that the association remains as an association between the first asset and a blockchain asset, in a way which is verifiable on the said ledger, after a transaction involving the blockchain asset in question,
• which second asset is either a second blockchain asset on the ledger in question or an asset registered as an association with a specific second blockchain asset on the said ledger,
• wherein the computer server is arranged to
• electronically receive, from a selling first party, a signed first blockchain transaction part comprising a first input blockchain transaction leg concerning the first blockchain asset in question;
• and receive, from a buying second party, a signed second blockchain transaction part comprising a second input blockchain transaction leg concerning the second blockchain asset in question;
• combine the first and second blockchain transaction parts in a single combined blockchain transaction comprising the first input blockchain transaction leg, the second input blockchain transaction leg, a first output blockchain transaction leg concerning the first blockchain asset and a second output blockchain transaction leg concerning the second blockchain asset;
• and
• publish the combined blockchain transaction on the blockchain ledger.

A client computer for performing an asset transaction in which a first asset is exchanged for a second asset,

• which first asset is either a first blockchain asset registered on a digitally and electronically accessed blockchain-based ledger or an asset registered as an association with a specific first blockchain asset on the ledger in question,
• which second asset is either a second blockchain asset on the ledger in question or an asset registered as an association with a specific second blockchain asset on the said ledger, which ledger is arranged to keep track of blockchain transactions concerning the blockchain asset in question from senders to specified blockchain asset ad dresses, which blockchain transactions are signed using a respective private cryptographic key belonging to the sender in question,
• wherein at least one of the first and second assets is registered as such an association, which association is arranged so that the association remains as an association between the first asset and a blockchain asset, in a way which is verifiable on the said ledger, after a transaction involving the blockchain asset in question,
• wherein the client computer is arranged to receive and verify, on the ledger, information regarding a second blockchain transaction part comprising a second input blockchain transaction leg concerning the second blockchain asset in question;
• to identify and sign a first blockchain transaction part comprising a first input blockchain transaction leg concerning the first blockchain asset in question;
• to provide the signed first blockchain transaction part to a central server;
• to receive information regarding a single combined blockchain transaction from the central server;
• to verify, on the ledger, that the combined blockchain transaction comprises, as input blockchain transaction legs, the first and second input blockchain transaction legs, and that the combined blockchain transaction comprises, as an output transaction legs, a blockchain transaction leg transferring the second blockchain asset to a specified second blockchain destination address.

A non-transitory computer readable medium storing a computer software product comprising executable code for settling an asset transaction in which a first asset is exchanged for a second asset,

• which first asset is registered as an association with a specific first blockchain asset on a digitally and electronically accessed blockchain-based ledger,
• which ledger is arranged to keep track of blockchain transactions concerning the blockchain asset in question from senders to specified blockchain asset addresses, which blockchain transactions are signed using a respective private cryptographic key belonging to the sender in question,
• which association is arranged so that the association remains as an association between the first asset and a blockchain asset, in a way which is verifiable on the said ledger, after a transaction involving the blockchain asset in question,
• which second asset is either a second blockchain asset on the ledger in question or an asset registered as an association with a specific second blockchain asset on the said ledger,
• wherein the computer software product, when executed on a computer server, is arranged to
• allow the computer server to electronically receive, from a selling first party, a signed first blockchain transaction part comprising a first input blockchain transaction leg concerning the first blockchain asset in question;
• and to receive, from a buying second party, a signed second blockchain transaction part comprising a second input block-chain transaction leg concerning the second blockchain asset in question;
• combine the first and second blockchain transaction parts in a single combined blockchain transaction comprising the first input blockchain transaction leg, the second input blockchain transaction leg, a first output blockchain transaction leg concerning the first blockchain asset and a second output blockchain transaction leg concerning the second blockchain asset;
• and
• publish the combined blockchain transaction on the blockchain ledger.

A non-transitory computer readable medium storing a computer software product comprising executable code for performing an asset transaction in which a first asset is exchanged for a second asset,

• which first asset is either a first blockchain asset registered on a digitally and electronically accessed blockchain-based ledger or an asset registered as an association with a specific first blockchain asset on the ledger in question, which second asset is either a second blockchain asset on the ledger in question or an asset registered as an association with a specific second blockchain asset on the said ledger,
• which ledger is arranged to keep track of blockchain transactions concerning the blockchain asset in question from senders to specified blockchain asset addresses, which blockchain transactions are signed using a respective private cryptographic key belonging to the sender in question,
• wherein at least one of the first and second assets is registered as such an association, which association is arranged so that the association remains as an association between the first asset and a blockchain asset, in a way which is verifiable on the said ledger, after a transaction involving the blockchain asset in question,
• wherein the computer software product, when executed on a client computer, is arranged to
• allow the client computer to receive, and to verify, on the ledger, information regarding a second blockchain transaction part comprising a second input blockchain trans action leg concerning the second blockchain asset in question;
• identify and sign a first blockchain transaction part comprising a first input blockchain transaction leg concerning the first blockchain asset in question;
• provide the signed first blockchain transaction part to a central server;
• allow the client computer to receive information regarding a single combined blockchain transaction from the central server;
• verify, on the ledger, that the combined blockchain transaction comprises, as input blockchain transaction legs, the first and second input blockchain transaction legs, and that the combined blockchain transaction comprises, as an output transaction leg, an output blockchain transaction leg transferring the second blockchain asset to a specified blockchain destination address.