COMPUTER-IMPLEMENTED SYSTEMS AND METHODS FOR IMPLEMENTING TRANSFERS OVER A BLOCKCHAIN NETWORK
The invention provides improved verification solutions for blockchain-implemented transfers. It is suited for, but not limited to, implementation in an SPV wallet. In accordance with one embodiment, a method, system or resource is provided in which Bob verifies a Merkle proof for a first transaction and, upon successful verification, submits a second transaction to the blockchain. The second transaction has an input that spends an output (UTXO) from the first transaction. Generally, the invention provides an arrangement in which Bob sends Alice a payment transaction template (template Tx 3 ) and requests: the full transaction data for all input transactions (Tx 1 , Tx 2 ) comprising at least one output that Alice wants to spend as inputs to a transfer (Tx 3 ); the Merkle path for all input transactions (Tx 1 , Tx 2 ) linking them to their respective Merkle roots associated with their respective block headers; the completed transfer transaction (Tx 3 ). Alice provides this information plus her signature and optionally a change address. Bob can then perform local SPV checks on the input transactions Tx 1 , Tx 2 using transactions Tx 1 and Tx 2 , their corresponding Merkle paths Path 1 , Path 2 , and Bob's local list of block headers. Bob broadcasts the transfer transaction (Tx 3 ) to the P2P network.
1 . A blockchain-implemented Simplified Payment Verification method, comprising the steps:
verifying a Merkle proof for a first transaction comprising an unspent output (UTXO 1 ); and
sending a second transaction to a blockchain upon successful verification of the Merkle proof, wherein the second transaction comprises an input which spends the unspent output (UTXO 1 ) of the first transaction.
2 . The method of claim 1 ,
wherein the second transaction comprises at least one further input which spends at least one further unspent output (UTXO 2 ) of the first transaction or an unspent output (UTXO 3 ) of a third transaction.
3 . The method of claim 2 , further comprising the step of:
verifying a Merkle proof for the third transaction.
4 . The method of claim 1 , further comprising the step of:
receiving, via an off-chain communication, at least one of a Merkle path or complete transaction data for at least one the first transaction and/or the third transaction.
5 . The method of claim 1 , further comprising the step of storing at least one of:
at least one public key;
at least one private key; or
at least one block header.
6 . The method of claim 2 , further comprising the step of:
requesting, via an off-chain communication, at least one of the Merkle path and/or complete transaction data for the first transaction or third transaction from a computer-based resource.
7 . The method of claim 6 , wherein the request is made using a transaction template.
8 . The method of claim 6 , further comprising the step of receiving, via an off-chain communication and from the computer-based resource:
the at least one of the Merkle path or the complete transaction data for the at least one of the first transaction or the third transaction; and
a signature for spending at least one unspent blockchain transaction output (UTXO) of the at least one of the first transaction or the third transaction.
9 . The method of claim 1 , wherein the second transaction further comprises a change address for spending a portion of cryptocurrency to a destination.
10 . A computer-implemented system, comprising:
a processor; and
memory including executable instructions that, as a result of execution by the processor, causes the computer-implemented system to perform the steps of:
verifying a Merkle proof for a first transaction comprising an unspent output (UTXO 1 ); and
sending a second transaction to a blockchain upon successful verification of the Merkle proof, wherein the second transaction comprises an input which spends the unspent output (UTXO 1 ) of the first transaction.
11 . The computer-implemented system of claim 10 wherein the computer-implemented system comprises at least one Simplified Payment Verification wallet.
12 . A non-transitory computer-readable storage medium having stored thereon executable instructions that, as a result of being executed by a processor of a computer system, cause the computer system to at least perform the steps of:
verifying a Merkle proof for a first transaction comprising an unspent output (UTXO 1 ); and
sending a second transaction to a blockchain upon successful verification of the Merkle proof, wherein the second transaction comprises an input which spends the unspent output (UTXO 1 ) of the first transaction.
13 . The computer-implemented system of claim 10 , wherein the second transaction comprises at least one further input which spends at least one further unspent output (UTXO 2 ) of the first transaction or an unspent output (UTXO 3 ) of a third transaction.
14 . The computer-implemented system of claim 13 , wherein the executable instructions, as a result of execution by the processor, cause the computer-implemented system to perform the step of verifying a Merkle proof for the third transaction.
15 . The computer-implemented system of claim 13 , wherein the executable instructions, as a result of execution by the processor, cause the computer-implemented system to perform the step of
receiving, via an off-chain communication, at least one of a Merkle path or complete transaction data for at least one of the first transaction or the third transaction.
16 . The non-transitory computer-readable storage medium of claim 12 , wherein the computer system comprises at least one Simplified Payment Verification wallet.
17 . The non-transitory computer-readable storage medium of claim 12 , wherein the second transaction comprises at least one further input which spends at least one further unspent output (UTXO 2 ) of the first transaction or an unspent output (UTXO 3 ) of a third transaction.
18 . The non-transitory computer-readable storage medium of claim 17 , wherein the executable instructions, as a result of being executed by the processor of the computer system, cause the computer system to at least perform the step of verifying a Merkle proof for the third transaction.
19 . The non-transitory computer-readable storage medium of claim 17 , wherein the executable instructions, as a result of being executed by the processor of the computer system, cause the computer system to at least perform the step of receiving, via an off-chain communication, at least one of a Merkle path or complete transaction data for the at least one of the transaction or the third transaction.
20 . The non-transitory computer-readable storage medium of claim 12 , wherein the executable instructions, as a result of being executed by the processor of the computer system, cause the computer system to at least perform the step of storing:
at least one public key;
at least one private key; and/or
at least one block header.