# US 12,602,683 B2 · Methods and apparatuses for generating, verifying and storing transaction voucher, devices and system

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- Number: US 12,602,683 B2
- Document ID: US12602683B2
- Status: Granted
- Kind: B2
- Application number: 18/283,779
- Filed: 2022-03-21
- Published: 2024-05-30
- Granted: 2026-04-14
- Earliest claimed: 2021-03-31
- Assignees: Digital Currency Institute, the People's Bank of China
- Applicants: Digital Currency Institute, The People's Bank of China
- Inventors: Wei Liang; Kefeng Xu; Yongchao Bian
- Web page: https://patentgrep.com/patent/US12602683B2

## CPC

- G06Q 20/065: {using e-cash}
- G06Q 20/387: {Payment using discounts or coupons (relating to marketing G06Q30/02)}
- G06Q 20/223: {based on the use of peer-to-peer networks}
- G06Q 20/3678: {e-cash details, e.g. blinded, divisible or detecting double spending}
- G06Q 20/382: {insuring higher security of transaction}
- G06Q 20/38215: {Use of certificates or encrypted proofs of transaction rights}
- G06Q 20/3825: {Use of electronic signatures}
- G06Q 20/3827: {Use of message hashing}
- G06Q 20/3829: {involving key management}
- G06Q 20/389: {Keeping log of transactions for guaranteeing non-repudiation of a transaction}
- G06Q 20/401: {Transaction verification}
- G06Q 30/0207: Discounts or incentives, e.g. coupons or rebates
- H04L 9/50: {using hash chains, e.g. blockchains or hash trees}
- H04L 2209/56: Financial cryptography, e.g. electronic payment or e-cash
- G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

Methods and apparatuses for generating, verifying and storing a transaction voucher, devices and a system are provided. The method includes: in response to a received transaction request, chain structure data of a digital currency is acquired, the chain structure data including a first currency string (S101); and a transaction voucher corresponding to a denomination of a current transaction is generated based on the chain structure data, the transaction voucher including a second currency string of a corresponding denomination and a second sub-chain, and the second sub-chain including current transaction information of the second currency string (S102). On the one hand, a pay warrant is provided for a transaction, so that the transaction is traceable, and the security of the transaction is ensured. On the other hand, the reading and storage efficiency of transaction data can be improved, and the transaction efficiency and the user experience can also be improved.

## Claims

### Claim 1

A method for generating a transaction voucher, comprising:
in response to a received transaction request, acquiring, by a payment device, chain structure data of a digital currency, the chain structure data comprising a first currency string;
generating, by the payment device, based on the chain structure data, a transaction voucher corresponding to a denomination of a current transaction, the transaction voucher comprising a second currency string of a corresponding denomination and a second sub-chain, and the second sub-chain comprising current transaction information of the second currency string, wherein generating, by the payment device, based on the chain structure data, a transaction voucher corresponding to a denomination of a current transaction further comprises: signing the second sub-chain by using a signature of the payment device, signing the second currency by using a two- stage signature generated by a central bank digital currency system and an operating agency digital currency system, and generating the transaction voucher based on the signed second currency string and the signed second sub-chain;
storing, by the payment device, the transaction voucher through a chain storage structure;
sending, by the payment device, the transaction voucher to a collection device;
obtaining, by a collection device, a received transaction voucher sent by a payment device, the transaction voucher comprising a second currency string and a second sub-chain, and the second sub-chain comprising current transaction information of the second currency string;
decrypting, by the collection device, the second currency string to obtain a signature;
verifying, by the collection device, that the signature of the second currency string is a two-stage signature generated by a central bank digital currency system and an operating agency digital currency system;
decrypting, by the collection device, the second sub-chain to obtain a signature; and
verifying that the signature of the second sub-chain is a signature of a payer corresponding to the payment device.

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein the chain structure data further comprises a first sub-chain, wherein the first sub-chain comprises historical transaction information of the first currency string, and the second sub-chain further comprises the first sub-chain.

### Claim 3 (depends on 1)

The method as claimed in claim 1, wherein a denomination of the first currency string is greater than a denomination of the second currency string; and
generating based on the chain structure data, the transaction voucher corresponding to the denomination of the current transaction comprises:
generating two or more pieces of first chain structure data based on the chain structure data, the two or more pieces of first chain structure data comprising the first sub-chain, and at least one piece of the first chain structure data comprising the second currency string; and
generating the transaction voucher based on the first chain structure data comprising the second currency string and the current transaction information of the second currency string.

### Claim 4 (depends on 3)

The method as claimed in claim 3, wherein generating the transaction voucher based on the first chain structure data comprising the second currency string and the current transaction information of the second currency string comprises:
connecting the first sub-chain in the first chain structure data comprising the second currency string to chain data generated based on the current transaction information of the second currency string, as to obtain the second sub-chain; and
signing the second sub-chain, and generating the transaction voucher based on the second currency string and the signed second sub-chain.

### Claim 5 (depends on 2)

The method as claimed in claim 2, wherein the first currency string and the second currency string are the same currency string; and
generating based on the chain structure data, the transaction voucher corresponding to the denomination of the current transaction comprises:
connecting the first sub-chain in the chain structure data to chain data generated based on the current transaction information of the second currency string, as to obtain the second sub-chain; and
signing the second sub-chain, and generating the transaction voucher based on the second currency string and the signed second sub-chain.

### Claim 6 (depends on 1)

The method as claimed in claim 1, after generating the transaction voucher, comprising:
deleting the chain structure data used for generating the transaction voucher from a chain storage structure in which the chain structure data is located.

### Claim 7 (depends on 6)

The method as claimed in claim 6, wherein the chain storage structure is a chain table, and the chain structure data is obtained by traversing the chain table.

### Claim 8 (depends on 1)

The method as claimed in claim 1, wherein a plurality of transaction vouchers are generated; each transaction voucher is generated based on one piece of chain structure data; first currency strings of various pieces of chain structure data respectively have respective denominations; a sum of denominations corresponding to the plurality of transaction vouchers is equal to a total digital currency amount of the current transaction; and
the method further comprises: generating a transaction voucher chain in a form of a data chain based on the plurality of transaction vouchers.

### Claim 9 (depends on 1)

The method as claimed in claim 1, after generating the transaction voucher corresponding to the denomination of the current transaction, comprising:
performing a hash operation by using a first random number and a second random number, to obtain a session key; and
encrypting the transaction voucher by using the session key, and sending the encrypted transaction voucher to a collection device.

### Claim 10 (depends on 9)

The method as claimed in claim 9, wherein in a case where it is verified that personal certificates of a payment device and the collection device are valid, performing the hash operation by using the first random number and the second random number, to obtain the session key is executed.

### Claim 11

A method for verifying a transaction voucher, comprising:
receiving, by a collection device, a transaction voucher sent by a payment device, the transaction voucher corresponding to a denomination of a current transaction;
obtaining, by the collection device, a second currency string of a corresponding denomination and a second sub-chain from the transaction voucher, the second sub-chain comprising current transaction information of the second currency string; and
respectively verifying, by the collection device, the second currency string and the second sub-chain to verify the transaction voucher, wherein respectively verifying the second currency string and the second sub-chain further comprises: decrypting the second currency string to obtain a signature, verifying that the signature of the second currency string is a two-stage signature generated by a central bank digital currency system and an operating agency digital currency system, decrypting the second sub-chain to obtain a signature, and verifying that the signature of the second sub-chain is a signature of a payer corresponding to the payment device.

### Claim 12 (depends on 11)

The method as claimed in claim 11, wherein receiving the transaction voucher sent by the payment device comprises: receiving a transaction voucher chain, sent by the payment device, in a form of a data chain, the transaction voucher comprising a plurality of transaction vouchers, and a sum of denominations corresponding to the plurality of transaction vouchers being equal to a total digital currency amount of the current transaction; and
obtaining the second currency string of the corresponding denomination and the second sub-chain from the transaction voucher comprises: obtaining the plurality of transaction vouchers from the transaction voucher chain, and obtaining the second currency string of the corresponding denomination and the second sub-chain from each transaction voucher.

### Claim 13

A method for storing a transaction voucher, comprising:
obtaining, by a collection device, a received transaction voucher sent by a payment device, the transaction voucher comprising a second currency string and a second sub-chain, and the second sub-chain comprising current transaction information of the second currency string;
decrypting the second currency string to obtain a signature;
verifying that the signature of the second currency string is a two-stage signature generated by a central bank digital currency system and an operating agency digital currency system;
decrypting the second sub-chain to obtain a signature;
verifying that the signature of the second sub-chain is a signature of a payer corresponding to the payment device; and
storing, by the collection device, the transaction voucher to a chain storage structure as chain structure data of a digital currency.

### Claim 14 (depends on 13)

The method as claimed in claim 13, wherein one transaction voucher is obtained; and
storing the transaction voucher to the chain storage structure as chain structure data of the digital currency comprises:
interpolating the transaction voucher to a data region of one node of the chain storage structure, the node further comprising a voucher region used for storing an address of a next node of the node.

### Claim 15 (depends on 13)

The method as claimed in claim 13, wherein a plurality of transaction vouchers are obtained, and the plurality of transaction vouchers form a transaction voucher chain in a form of a data chain; and
storing the transaction voucher to the chain storage structure as the chain structure data of the digital currency comprises:
interpolating the plurality of transaction vouchers of the transaction voucher chain to data regions of a plurality of nodes of the chain storage structure based on an order of the plurality of transaction vouchers in the transaction voucher chain, each node further comprising a voucher region used for storing an address of a next node of the corresponding node.

### Claim 16 (depends on 13)

The method as claimed in claim 13, wherein storing the transaction voucher to the chain storage structure as the chain structure data of the digital currency comprises:
modifying a preset logo on the transaction voucher to another locally preset logo, as to transform the transaction voucher into a balance voucher, and storing the balance voucher to the chain storage structure.

### Claim 17 (depends on 13)

The method as claimed in claim 13, wherein the chain storage structure is a chain table.

### Claim 18 (depends on 13)

The method as claimed in claim 13, wherein the chain storage structure is stored in a local secure element (SE) chip.