CN107392603A - Use the method for commerce and device of digital cash - Google Patents

Abstract

The invention discloses a transaction method and device using digital currency, and relates to the field of computer technology. A specific implementation of the method includes: in the process of receiving and payment transactions based on distributed ledger technology, the payer encrypts the plaintext amount involved in the transaction to obtain the ciphertext amount, and generates a corresponding verification message to verify The ciphertext amount is verified or decrypted. This implementation method solves the technical problem that funds are difficult to keep secret in the existing distributed ledger technology, and achieves the technical effect of ensuring cooperation and sharing and protecting transaction privacy.

Description

Transaction method and device using digital currency

technical field

The invention relates to the field of computer technology, in particular to a transaction method and device using digital currency.

Background technique

Blockchain is a new type of distributed technology. Protocol makers formulate and publish rules before the system runs, and develop clients that follow the protocol. Afterwards, multiple institutions or individuals act as nodes to connect and run the system. On the client side, the data generated by malicious nodes that do not conform to the agreement will be discarded by other honest nodes. This method of confrontational consensus is used to jointly maintain a general ledger, so that no centralized authority or individual can tamper with the initial agreement. imagine.

The first blockchain application scenario is Bitcoin, which implements a currency system that stipulates issuance rules and transfer logic in advance. The source of currency issuance is the block reward Coinbase of the bookkeeping node, and the currency transfer logic is called unspent. Transaction output (Unspent Transaction Output: UTXO) model. Assuming that user A currently has currencies A1(￥5), A2(￥4), and A3(￥1), the sources of these currencies all come from block rewards, and user A wants to transfer 7 yuan to user B, then user A collects For the currency in hand, find a combination greater than or equal to 7, initiate a transaction with A1 and A2 as input (input), and change currency A4 (￥2) and nascent currency B1 (￥7) as output (output), that is, A1 (￥5)+A2(￥4)＝>A4(￥2)+B1(￥7), this equation needs to be verified by the accounting node first, after passing and writing into the blockchain, A1 and A2 will be Become spent currency, A4 and B1 become new unspent currency, which can be used as input for future UTXO structures.

Since the bookkeeping node needs to verify whether each transaction has negative currency, whether there is an excess transfer, whether there is currency creation, etc., the blockchain system represented by Bitcoin chooses to store all users’ unspent currency information in plain text. Moreover, the newly generated currency information in the transaction also needs to be clearly stated, so that nodes can verify the relationship between input and output of all UTXOs.

However, in the process of realizing the present invention, the inventor found that there are at least the following problems in the prior art: in real life, the point-to-point transaction amount between users (enterprises or individuals) generally has confidentiality requirements, and the total balance of users in the system also has Confidentiality needs. Traditional centralized solutions can easily set data access rights without cooperative bookkeeping, which can solve the privacy problem well, but users still hope to use the advantages of distributed technology such as blockchain to store multi-party data. Other documents and data of cooperation, however, a complete business closed loop requires funds to participate in real-time clearing and settlement, which leads to the problem that cooperation sharing and transaction privacy cannot coexist.

Contents of the invention

In view of this, the embodiments of the present invention provide a transaction method and device using digital currency, which can realize the encryption of the transaction amount during the transaction process using digital currency, so as to protect the privacy rights of users.

In order to achieve the above purpose, according to an aspect of the embodiment of the present invention, a transaction method using digital currency is provided, including:

The payment end encrypts the received plaintext transaction amount to obtain the ciphertext transaction amount, and generates first verification information for verifying the ciphertext transaction amount;

The payment end calculates the plaintext change amount according to the plaintext transaction amount and the currency list, and encrypts the plaintext change amount to obtain the ciphertext change amount, and then generates a second password for verifying the ciphertext change amount. verify message;

The payment terminal generates a payment request and broadcasts the payment request; the payment request includes the ciphertext transaction amount, the first verification information, the ciphertext change amount and the second verification information;

After receiving the payment request, the node confirms that the ciphertext transaction amount complies with the rules according to the first verification information, and confirms that the ciphertext change amount complies with the rules according to the second verification information, and then sends the Payment requests are stored to the blockchain.

In some optional embodiments, the step of the payment terminal encrypting the received plaintext transaction amount to obtain the ciphertext transaction amount includes:

The payment terminal generates the transaction private key used for this payment;

The payment end stores the base point value, and uses the base point encryption algorithm to encrypt and calculate the base point value to obtain the base point check value;

The payer calculates the ciphertext transaction amount according to the formula q=xG+mH; where, q is the ciphertext transaction amount, x is the transaction private key, m is the received plaintext transaction amount, and G is the The base point value, H is the check value of the base point.

In some optional embodiments,

The first verification information includes a first transaction certificate;

The step for the payment terminal to generate the first verification information for verifying the ciphertext transaction amount includes:

The payment side performs binary splitting of the plaintext transaction amount m according to the preset number of digits n to obtain Where m _i =2 ⁱ or m _i =0, i represents an index bit, and 0≤i<n;

The payment side randomly splits the transaction private key x according to the preset number of digits n to obtain Among them, x ₀ to x _n-2 are randomly generated,

For each index bit, the payer calculates according to P(x _i ,m _i )=x _i G+m _i H and P(x _i ,m _i -k _i )=x _i G+(m _i -k _i )H P(x _i , m _i ) and P(x _i , m _i -k _i ); where k _i =2 ⁱ ;

For each index bit, the payer uses the x _i , the P( _xi ,m _i ) and the P( _xi ,m _i -k _i ) to generate the ring signature S _i of the index bit;

The payer concatenates all the index bits, the P( _xi ,m _i ), the P( _xi ,m _i - _ki ) and the S _i to obtain the first transaction proof.

In some optional embodiments, the step of the node confirming that the encrypted transaction amount complies with the rules according to the first verification information includes:

The node disassembles the first transaction proof to obtain all the index bits, the P( _xi ,m _i ), the P( _xi ,m _{i -ki ) and the S i ;}

The node confirms that for each of the index bits, the S _i is the ring signature of the P( _xi ,m _i ) and the P( _xi ,m _i -ki ₎ , and confirms that for each of the Index bit, satisfy P( _xi ,m _i )-P( _xi ,m _i -k _i )=k _i H, and then confirm that To confirm that the ciphertext transaction amount complies with the rules; where k _i =2 ⁱ .

In some optional embodiments,

The first verification information includes a first communication message;

The step for the payment terminal to generate the first verification information for verifying the ciphertext transaction amount includes:

The payer generates the fixed private key of the payer, obtains the fixed public key of the payee, and uses the base point encryption algorithm to encrypt and calculate the product of the fixed private key of the payer and the fixed public key of the payee to obtain a shared secret key, and then concatenate the plaintext transaction amount with the transaction private key, and then use the shared key to encrypt and calculate the concatenated result to generate the first communication message.

In some optional embodiments, the step of calculating the clear text change amount according to the plain text transaction amount and the currency list at the payment end includes:

The payer selects the digital currency whose payee is the payer and the total plaintext amount is greater than or equal to the plaintext transaction amount from the currency list to form a currency subset, and then subtracts the plaintext transaction from the plaintext total amount Amount to get the change amount in plain text.

In some optional embodiments, the payment request includes transaction currency and change currency, the transaction currency includes the encrypted transaction amount and the first verification information, and the change currency includes the The ciphertext change amount and the second verification information;

The payment request also includes a transfer data structure;

Before the steps of generating a payment request on the payment side, it also includes:

The payment terminal generates a transfer data structure including the hash value of the transaction currency, the hash value of the change currency, and the hash values of each digital currency in the currency subset.

In some optional embodiments,

Before the step of the node updating the currency list according to the payment request, it also includes: the node establishes a currency list for storing currency, currency hash value and the corresponding relationship between the two; the currency list includes an unspent currency list and a confirmed currency list and a list of spent currencies;

Before the node stores the payment request in the block chain, it also includes: the node searches and confirms that the digital currency in the currency subset is stored in the currency subset according to the hash value of the digital currency in the currency subset A list of unspent currencies, and confirming that the sum of the ciphertext transaction amount and the ciphertext change amount is equal to the total ciphertext amount of digital currencies in the currency subset.

In order to achieve the above purpose, according to another aspect of the embodiments of the present invention, a transaction device using digital currency is provided, including:

The transaction amount encryption module is used to encrypt the received plaintext transaction amount to obtain the ciphertext transaction amount;

A first verification information generating module, configured to generate first verification information for verifying the encrypted transaction amount;

A change amount calculation module, configured to calculate the plaintext change amount according to the plaintext transaction amount and currency list;

The change amount encryption module is used to encrypt the plaintext change amount to obtain the ciphertext change amount;

A second verification information generating module, configured to generate second verification information for verifying the ciphertext change amount;

A payment request sending module, configured to generate a payment request and broadcast the payment request; the payment request includes the ciphertext transaction amount, the first verification information, the ciphertext change amount and the second verification information .

In some optional embodiments, the transaction amount encryption module is also used to: generate the transaction private key used in this payment; store the base point value, and use the base point encryption algorithm to encrypt and calculate the base point value to obtain the base point calibration check value; calculate the ciphertext transaction amount according to the formula q=xG+mH; wherein, q is the ciphertext transaction amount, x is the transaction private key, m is the received plaintext transaction amount, and G is The base point value, H is the base point check value.

In some optional embodiments,

The first verification information includes a first transaction certificate;

The first verification information generation module is also used to: perform binary splitting of the plaintext transaction amount m according to the preset number of digits n, to obtain Where m _i =2 ⁱ or m _i =0, i represents the index bit, and 0≤i<n; randomly split the transaction private key x according to the preset number of bits n to obtain Among them, x ₀ to x _n-2 are randomly generated, _{For each index bit , calculate P ( _ _ xi} , m _i ) and P( _xi , m _i -ki ); where _ki =2 _i ; for each index bit, use the ^xi , the P( _xi ,m _{i )} and the P( _xi ,m _{i -ki} ) to generate the ring signature S _i of the index bit; combine all the index bits, the P( _xi ,m _i ), the P( _xi , m _{i -ki ) and the S i are} spliced to obtain the first transaction proof.

In some optional embodiments,

The first verification information includes a first communication message;

The first verification information generation module is also used to: generate a fixed private key of the payment terminal, obtain a fixed public key of the payment terminal, and use the base point encryption algorithm to compare the fixed private key of the payment terminal with the fixed public key of the payment terminal. key product to obtain a shared key, then concatenate the plaintext transaction amount with the transaction private key, and then use the shared key to encrypt the concatenated result to generate the first communication information.

In some optional embodiments, the change amount calculation module is further configured to: select a digital currency whose payee is the payment terminal from the currency list and whose total plaintext amount is greater than or equal to the plaintext transaction amount, and then A currency subset is formed, and then the plaintext transaction amount is subtracted from the plaintext total amount to obtain the plaintext change amount.

In some optional embodiments, the payment request includes transaction currency and change currency, the transaction currency includes the encrypted transaction amount and the first verification information, and the change currency includes the The ciphertext change amount and the second verification information;

The payment request also includes a transfer data structure;

The device also includes:

A transfer data structure generation module, configured to generate a transfer data structure including the hash value of the transaction currency, the hash value of the change currency, and the hash values of each digital currency in the currency subset.

In order to achieve the above purpose, according to another aspect of the embodiment of the present invention, a transaction device using digital currency is provided, including:

A payment request receiving module, configured to receive a payment request; the payment request includes encrypted transaction amount, first verification information, encrypted change amount and second verification information;

A transaction amount verification module, configured to confirm that the ciphertext transaction amount complies with the rules according to the first verification information;

A change amount verification module, configured to confirm that the ciphertext change amount complies with the rules according to the second verification information;

The payment request chain entry module is used to store the payment request into the block chain.

In some optional embodiments,

The first verification information includes a first transaction certificate;

The transaction amount verification module is also used to: disassemble the first transaction certificate to obtain all index bits i, P( _xi ,m _i ), P( _xi ,m _i -k _i ) and S _i ; Confirm that for each of the index bits, the S _i is the ring signature of the P( _xi ,m _i ) and the P( _xi ,m _i -ki ₎ , and confirm that for each of the Index bit, satisfy P( _xi ,m _i )-P( _xi ,m _i -k _i )=k _i H, and then confirm that To confirm that the ciphertext transaction amount complies with the rules; where q is the ciphertext transaction amount, k _i =2 ⁱ .

In some optional embodiments, the device further includes a currency list establishment module and a currency list verification module, wherein,

The currency list establishment module is used to establish a currency list for storing currency, currency hash value and the corresponding relationship between the two; the currency list includes an unspent currency list, a confirmed currency list and a spent currency list;

The payment request includes transaction currency and change currency, the transaction currency includes the ciphertext transaction amount and the first verification information, and the change currency includes the ciphertext change amount and the Second authentication information;

The transfer data structure includes the hash value of the transaction currency, and the transfer data structure further includes the hash value of the change currency and the hash value of the digital currency in the currency subset;

The currency list verification module is used to: search and confirm that the transaction currency is stored in the currency list in the confirmation according to the hash value of the transaction currency, and then search and confirm according to the hash value of the digital currency in the currency subset Confirming that the currency in the currency subset is stored in the unspent currency list, and confirming that the sum of the encrypted transaction amount and the encrypted change amount is equal to the total encrypted amount of the digital currency in the currency subset .

In order to achieve the above object, according to still another aspect of the embodiments of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium stores computer instructions, which is characterized in that the computer instructions can be read by a computer or The computer system operates so that the computer or computer system can execute the described transaction method using digital currency.

An embodiment of the above invention has the following advantages or beneficial effects: Because in the process of using the payment transaction based on distributed ledger technology, the payment end encrypts the plaintext amount involved in the transaction to obtain the ciphertext amount, and generates the corresponding verification The message is a technical means for verifying or decrypting the ciphertext amount, so it overcomes the technical problem that the funds in the existing distributed ledger technology are difficult to keep secret, and then achieves the technical effect of ensuring cooperation and sharing and protecting transaction privacy.

The further effects of the above-mentioned non-conventional alternatives will be described below in conjunction with specific embodiments.

Description of drawings

The accompanying drawings are used to better understand the present invention, and do not constitute improper limitations to the present invention. in:

FIG. 1 is a schematic diagram of the main steps of a transaction method using digital currency according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of main modules of a transaction device using digital currency according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of main modules of a transaction device using digital currency according to another embodiment of the present invention.

detailed description

Exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, which include various details of the embodiments of the present invention to facilitate understanding, and they should be regarded as exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

Fig. 1 is a schematic diagram of main steps of a transaction method using digital currency according to an embodiment of the present invention.

As shown in Figure 1, the transaction method using digital currency provided according to the embodiment of the present invention includes:

S10. The payer encrypts the received plaintext transaction amount to obtain a ciphertext transaction amount, and generates first verification information for verifying the ciphertext transaction amount.

S11, the payer calculates the plaintext change amount according to the plaintext transaction amount and the currency list, and encrypts the plaintext change amount to obtain the ciphertext change amount, and then generates a password for verifying the ciphertext change amount Second authentication information.

S12. The payer generates a payment request and broadcasts the payment request; the payment request includes the ciphertext transaction amount, the first verification information, the ciphertext change amount, and the second verification information.

S13. After receiving the payment request, the node confirms that the ciphertext transaction amount complies with the rules according to the first verification information, and confirms that the ciphertext change amount complies with the rules according to the second verification information, and then sends Said payment request is stored to the blockchain.

In some optional embodiments, the payment request further includes a payment time stamp. In order to facilitate sending, receiving and recording, the payment request also includes the address of the payee and the address of the payer. In order to facilitate identification, the payment request is signed by the payer using the fixed private key of the payer before broadcasting.

It can be seen from the above that, in the embodiment of the present invention, during the payment transaction based on distributed ledger technology, the payer encrypts the plaintext amount involved in the transaction to obtain the ciphertext amount, and generates a corresponding verification message, It is a technical means to verify or decrypt the amount of ciphertext, so it overcomes the technical problem that the funds in the existing distributed ledger technology are difficult to keep secret, and then achieves the technical effect of ensuring cooperation and sharing and protecting transaction privacy.

In some optional embodiments, the step of the payment terminal encrypting the received plaintext transaction amount to obtain the ciphertext transaction amount includes:

The payment terminal generates the transaction private key used for this payment;

The payment end stores the base point value, and uses the base point encryption algorithm to encrypt and calculate the base point value to obtain the base point check value;

The payer calculates the ciphertext transaction amount according to the formula q=xG+mH; where, q is the ciphertext transaction amount, x is the transaction private key, m is the received plaintext transaction amount, and G is the The base point value, H is the check value of the base point.

The base point encryption algorithm may be, for example, SHA256 algorithm, RIPEMD-160 algorithm, or Base58 encoding. The purpose of the base point encryption algorithm is to calculate a public public key that no one knows the private key through the preset base point value G, that is, the base point check value H; and the base point check value H obtained by using a hash algorithm such as SHA256 It is more credible, and of course other algorithms that can achieve the same or similar effects can also be used. The base point encryption algorithm needs to ensure that there is no simple correspondence between the calculated H and G, such as H=kG, so that q=xG+mH when q, G, and H are all known, the values of x and m has a unique solution.

In some optional embodiments, the first verification information includes a first transaction certificate;

The step for the payment terminal to generate the first verification information for verifying the ciphertext transaction amount includes:

The payment side performs binary splitting of the plaintext transaction amount m according to the preset number of digits n to obtain Where m _i =2 ⁱ or m _i =0, i represents an index bit, and 0≤i<n;

The payment side randomly splits the transaction private key x according to the preset number of digits n to obtain Among them, x ₀ to x _n-2 are randomly generated, When splitting, the larger the preset number of bits n, the higher the degree of encryption, but it will also increase the calculation cost, and the extra number of bits does not have practical applicability, so the value of n is usually 64 is more appropriate, depending on the situation You can also choose 32 or 128;

For each index bit, the payer calculates according to P(x _i ,m _i )=x _i G+m _i H and P(x _i ,m _i -k _i )=x _i G+(m _i -k _i )H P(x _i , m _i ) and P(x _i , m _i -k _i ); where k _i =2 ⁱ ;

For each index bit, the payer uses the x _i , the P( _xi ,m _i ) and the P( _xi ,m _i -k _i ) to generate the ring signature S _i of the index bit;

The payer concatenates all the index bits, the P( _xi ,m _i ), the P( _xi ,m _i - _ki ) and the S _i to obtain the first transaction proof.

In some optional embodiments, the step of the node confirming that the encrypted transaction amount complies with the rules according to the first verification information includes:

The node disassembles the first transaction proof to obtain all the index bits, the P( _xi ,m _i ), the P( _xi ,m _{i -ki ) and the S i ;}

The node confirms that for each of the index bits, the S _i is the ring signature of the P( _xi ,m _i ) and the P( _xi ,m _i -ki ₎ , and confirms that for each of the Index bit, satisfy P( _xi ,m _i )-P( _xi ,m _i -k _i )=k _i H, and then confirm that To confirm that the ciphertext transaction amount complies with the rules; where k _i =2 ⁱ .

In some optional embodiments, the first verification information includes a first communication message;

The step for the payment terminal to generate the first verification information for verifying the ciphertext transaction amount includes:

The payer generates the fixed private key of the payer, obtains the fixed public key of the payee, and uses the base point encryption algorithm to encrypt and calculate the product of the fixed private key of the payer and the fixed public key of the payee to obtain a shared secret key, and then concatenate the plaintext transaction amount with the transaction private key, and then use the shared key to encrypt and calculate the concatenated result to generate the first communication message.

When the payment terminal needs to decrypt the ciphertext transaction amount according to the first verification information, store the base point value, and use the base point encryption algorithm to encrypt and calculate the base point value to obtain the base point check value; generate a fixed private key at the receiving end, obtain a fixed public key at the paying end, and use the base point encryption algorithm to encrypt and calculate the product of the fixed private key at the receiving end and the fixed public key at the paying end to obtain a shared secret key, and then split the result of decrypting and computing the first communication message using the shared key to obtain the plaintext transaction amount.

In some optional embodiments, the step of calculating the clear text change amount according to the plain text transaction amount and the currency list at the payment end includes:

The payer selects the digital currency whose payee is the payer and the total plaintext amount is greater than or equal to the plaintext transaction amount from the currency list to form a currency subset, and then subtracts the plaintext transaction from the plaintext total amount Amount to get the change amount in plaintext. It should be noted that if the total plaintext amount of the digital currency in the currency subset is equal to the plaintext transaction amount, the calculated plaintext change amount is zero; in this case, the plaintext change amount can still be used The method that is not 0 is used for subsequent processing, and a separate judgment condition can also be set, so that the amount of change in plain text and related content that appear later will not be processed. If the follow-up processing is carried out according to the method that the plaintext change amount is not 0, it can be consistent with the node’s verification of the ciphertext transaction amount, ciphertext change amount, and the total plaintext amount of the digital currency in the currency subset in the subsequent steps, which can improve Integrity and security of the method.

In some optional embodiments, the payment request includes transaction currency and change currency, the transaction currency includes the encrypted transaction amount and the first verification information, and the change currency includes the The ciphertext change amount and the second verification information;

The payment request also includes a transfer data structure;

Before the steps of generating a payment request on the payment side, it also includes:

The payment terminal generates a transfer data structure including the hash value of the transaction currency, the hash value of the change currency, and the hash values of each digital currency in the currency subset.

The generation and use of the second verification information refers to the first verification information. It should be noted that when generating the second verification information, the payment transaction private key used for this payment is generated by the payer. In some other embodiments, in order to meet the verification conditions, the payment transaction private key must also meet certain conditions , which will be described in subsequent embodiments; if the second communication message needs to be generated, the payer will encrypt and generate it according to the fixed private key of the payment slip and the fixed public key of the payer, referring to the generation method of the first verification message.

In some optional embodiments,

Before the step of the node updating the currency list according to the payment request, it also includes: the node establishes a currency list for storing currency, currency hash value and the corresponding relationship between the two; the currency list includes an unspent currency list and a confirmed currency list and a list of spent currencies;

Before the node stores the payment request in the block chain, it also includes: the node searches and confirms that the transaction currency is stored in the currency list in the confirmation according to the hash value of the transaction currency, and then according to the The hash value of the digital currency in the currency subset looks up and confirms that the digital currency in the currency subset is stored in the unspent currency list, and confirms that the sum of the ciphertext transaction amount and the ciphertext change amount is equal to The total amount of ciphertext of digital currency in the currency subset.

In this embodiment, because it is confirmed that the sum of the ciphertext transaction amount and the ciphertext change amount is equal to the total ciphertext amount of the digital currency in the currency subset, when the plaintext of the digital currency in the currency subset The total amount is equal to the plaintext transaction amount, that is, when the value of the plaintext change amount is 0, it is still necessary to encrypt the plaintext change amount by referring to the method for encrypting the plaintext transaction amount; When encrypting, the payment transaction private key is generated by the payer. The generation method of the payment transaction private key here is different from that of the payee. It is not randomly generated, but the transaction private key of the digital currency in the currency subset. The result obtained by subtracting the transaction private key of the payment terminal from the sum of the private keys of the payment terminal is used as the payment transaction private key of the payment terminal, so that when the plaintext change amount is 0, the relationship between the ciphertext transaction amount and the ciphertext change amount can still be satisfied. The sum is equal to the total amount of ciphertext of the digital currency in the currency subset, thus completing the verification process.

In some optional embodiments, after the node stores the payment request in the block chain, it also includes: the node stores the transaction currency and its hash value in the unspent currency list, and then according to the After finding the currency in the currency subset by the hash value of the digital currency in the currency subset, move the currency in the currency subset and its hash value from the unspent currency list to the spent currency list a list of currencies, and storing the change currency and its hash value in the list of unspent currencies.

It should be noted that if any client needs to query its own account balance, it can collect the currencies whose payee address is its own address in the unspent currency list of the currency list, and calculate each currency one by one according to the public key of the payment terminal of these currencies and use the shared key to decrypt the ciphertext amounts in these currencies respectively to obtain the plaintext amounts of each currency, and add these plaintext amounts to obtain their own account balances.

In some optional embodiments, the data structures of the transaction currency, change currency and digital currency are shown in Table 1:

Table 1 Currency data structure table

field abbreviation Types of Explanation AddressFrom _x address Payer's address AddressTo _x address Payee address Money q public key ciphertext amount Proof f Bytes proof of transaction message c Bytes communication message Timestamp the s time Timestamp in milliseconds

In some optional embodiments, the data structure of the transaction proof is shown in Table 2:

Table 2 Transaction proof data structure table

In some optional embodiments, the optional data structure of the transfer data structure is shown in Table 3:

Table 3 transfer data structure table

field Types of Explanation Inputs Hash list Enter a list of currency hashes Outputs Hash list Output currency hash list

Wherein, the input currency hash list includes the hash value of the digital currency in the currency subset; the output currency hash list includes the transaction currency hash value, and when there is change, it also includes the The hash value of the change currency.

Fig. 2 is a schematic diagram of main modules of a transaction device using digital currency according to an embodiment of the present invention.

As shown in Figure 2, the embodiment of the present invention provides a transaction device 200 using digital currency, which is mainly applied to a client terminal with a payment function, including:

The transaction amount encryption module 201 is used to encrypt the received plaintext transaction amount to obtain the ciphertext transaction amount;

A first verification information generating module 202, configured to generate first verification information for verifying the encrypted transaction amount;

A change amount calculation module 203, configured to calculate the clear text change amount according to the plain text transaction amount and currency list;

A change amount encryption module 204, configured to encrypt the plaintext change amount to obtain a ciphertext change amount;

A second verification information generating module 205, configured to generate second verification information for verifying the ciphertext change amount;

A payment request sending module 206, configured to generate a payment request and broadcast the payment request; the payment request includes the ciphertext transaction amount, the first verification information, the ciphertext change amount and the second verification information.

In some optional embodiments, the transaction amount encryption module 201 is also used for:

Generate the transaction private key used for this payment; store the base point value, and use the base point encryption algorithm to encrypt and calculate the base point value to obtain the base point check value; calculate the ciphertext transaction amount according to the formula q=xG+mH; where , q is the ciphertext transaction amount, x is the transaction private key, m is the received plaintext transaction amount, G is the base point value, and H is the base point check value.

In some optional embodiments, the first verification information includes a first transaction certificate;

The first verification information generating module 202 is further configured to: perform binary splitting of the plaintext transaction amount m according to a preset number of digits n, to obtain Where m _i =2 ⁱ or m _i =0, i represents the index bit, and 0≤i<n; randomly split the transaction private key x according to the preset number of bits n to obtain Among them, x ₀ to x _n-2 are randomly generated, _{For each index bit , calculate P ( _ _ xi} , m _i ) and P( _xi , m _i -ki ); where _ki =2 _i ; for each index bit, use the ^xi , the P( _xi ,m _{i )} and the P( _xi ,m _{i -ki} ) to generate the ring signature S _i of the index bit; combine all the index bits, the P( _xi ,m _i ), the P( _xi , m _{i -ki ) and the S i are} spliced to obtain the first transaction proof.

In some optional embodiments, the first verification information includes a first communication message;

The first verification information generation module 202 is further configured to: generate a fixed private key of the payment terminal, obtain a fixed public key of the payment terminal, and use the base point encryption algorithm to perform a fixed private key connection between the fixed private key of the payment terminal and the fixed public key of the payment terminal. The product of the public key is encrypted and calculated to obtain a shared key, and then the plaintext transaction amount is spliced with the transaction private key, and then the result after splicing is encrypted and calculated using the shared key to generate the first communication message.

In some optional embodiments, the change amount calculation module 203 is further configured to: select a digital currency whose payee is the payment terminal and whose total plaintext amount is greater than or equal to the plaintext transaction amount from the currency list Then a currency subset is formed, and the plaintext transaction amount is subtracted from the plaintext total amount to obtain the plaintext change amount.

In some optional embodiments, the payment request includes transaction currency and change currency, the transaction currency includes the encrypted transaction amount and the first verification information, and the change currency includes the The ciphertext change amount and the second verification information;

The payment request also includes a transfer data structure;

The device also includes:

A transfer data structure generation module 207, configured to generate a transfer data structure including the hash value of the transaction currency, the hash value of the change currency, and the hash values of each digital currency in the currency subset.

Fig. 3 is a schematic diagram of main modules of a transaction device using digital currency according to another embodiment of the present invention.

As shown in Figure 3, another embodiment of the present invention provides a transaction device 300 using digital currency, which is mainly applied to nodes with verification functions, including:

A payment request receiving module 301, configured to receive a payment request; the payment request includes encrypted text transaction amount, first verification information, encrypted text change amount and second verification information;

A transaction amount verification module 302, configured to confirm that the ciphertext transaction amount complies with the rules according to the first verification information;

A change amount verification module 303, configured to confirm that the ciphertext change amount complies with the rules according to the second verification information;

The payment request chaining module 304 is configured to store the payment request in the block chain.

In some optional embodiments, the first verification information includes a first transaction certificate;

The transaction amount verification module 302 is also used to: disassemble the first transaction certificate to obtain all index bits i, P( _xi ,m _i ), P( _xi ,m _{i -ki} ) and S _i ; Confirm that for each of the index bits, the S _i is the ring signature of the P( _xi ,m _i ) and the P( _xi ,m _i -ki ₎ , and confirm that for each of the The index bit, satisfy P( _xi ,m _i )-P( _xi ,m _i -k _i )=k _i H, and then confirm that To confirm that the ciphertext transaction amount complies with the rules; where q is the ciphertext transaction amount, k _i =2 ⁱ .

In some optional embodiments, the device further includes a currency list establishment module 305 and a currency list verification module 306, wherein,

The currency list establishment module 305 is used to establish a currency list for storing currency, currency hash value and the corresponding relationship between the two; the currency list includes an unspent currency list, a confirmed currency list and a spent currency list;

The payment request includes transaction currency and change currency, the transaction currency includes the ciphertext transaction amount and the first verification information, and the change currency includes the ciphertext change amount and the Second authentication information;

The transfer data structure includes the hash value of the transaction currency, and the transfer data structure further includes the hash value of the change currency and the hash value of the digital currency in the currency subset;

The currency list verification module 306 is configured to: find and confirm that the currency in the currency subset is stored in the unspent currency list according to the hash value of the digital currency in the currency subset, and confirm the encrypted transaction The sum of the amount and the ciphertext change amount is equal to the total ciphertext amount of the digital currency in the currency subset.

The above specific implementation methods do not constitute a limitation to the protection scope of the present invention. It should be apparent to those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (18)

1. use the method for commerce of digital cash, it is characterised in that including：

Payment end the plaintext dealing money received is encrypted to obtain ciphertext dealing money, and generates described for verifying First checking information of ciphertext dealing money；

End is paid the bill according to the plaintext dealing money and the currency table calculating plaintext small change amount of money, and to plaintext small change gold Volume is encrypted to obtain the ciphertext small change amount of money, then generates the second checking information for verifying the ciphertext small change amount of money；

Payment end generates payment request and broadcasts the payment request；The payment request include the ciphertext dealing money, First checking information, the ciphertext small change amount of money and second checking information；

Node confirms that the ciphertext dealing money meets rule after the payment request is received, according to first checking information Then, and according to second checking information confirm that the ciphertext small change amount of money meets rule, then deposit the payment request Store up block chain.

2. according to the method for claim 1, it is characterised in that payment end the plaintext dealing money received is encrypted with The step of obtaining ciphertext dealing money includes：

Payment end generates the transaction private key that this payment uses；

Payment end storage basic point value, and the basic point value is encrypted using basic point AES and calculates and then obtain basic point Check value；

End is paid the bill according to the formula q=xG+mH calculating ciphertext dealing money；Wherein, q is the ciphertext dealing money, and x is institute Transaction private key is stated, m is the plaintext dealing money received, and G is the basic point value, and H is the basic point check value.

3. according to the method for claim 2, it is characterised in that first checking information, which includes the first transaction, to be proved；

The step of payment end generates the first checking information for verifying the ciphertext dealing money includes：

The plaintext dealing money m is carried out binary system fractionation by payment end according to presetting digit capacity n, to obtain Wherein m_i=2ⁱOr m_i=0, i represent index bit, and 0≤i ＜ n；Payment end enters the transaction private key x according to presetting digit capacity n Row is random to be split, to obtainWherein x₀To x_n-2Random generation,

End is paid the bill for each index bit, according to P (x_i,m_i)=x_iG+m_iH and P (x_i,m_i-k_i)=x_iG+(m_i-k_i) H calculating P (x_i,m_i) and P (x_i,m_i-k_i)；Wherein k_i=2ⁱ；

End is paid the bill for index bit each described, uses the x_i, P (the x_i,m_i) and the P (x_i,m_i-k_i) generate the rope Draw the ring signatures S of position_i；

Pay the bill end by whole the index bit, the P (x_i,m_i), the P (x_i,m_i-k_i) and the S_iSpliced to obtain First transaction proves.

4. according to the method for claim 3, it is characterised in that node confirms the ciphertext according to first checking information The legal step of dealing money includes：

Node is disassembled first transaction and proved, to obtain whole index bits, the P (x_i,m_i), the P (x_i,m_i- k_i) and the S_i；

Node is confirmed for index bit each described, the S_iFor the P (x_i,m_i) and the P (x_i,m_i-k_i) ring signatures, And confirm for index bit each described, meet P (x_i,m_i)-P(x_i,m_i-k_i)=k_iH, then confirm to meetTo confirm that the ciphertext dealing money meets rule；Wherein k_i=2ⁱ。

5. according to the method for claim 2, it is characterised in that first checking information includes the first communication information；

The step of payment end generates the first checking information for verifying the ciphertext dealing money includes：

Payment end generation payment end fixed private, obtains gathering end fixed public, and use the basic point AES to institute Calculating is encrypted to obtain shared key in the product for stating payment end fixed private and the gathering end fixed public, then by institute State literary dealing money clearly with the transaction private key to be spliced, reuse the shared key and spliced result is encrypted Calculate to generate first communication information.

6. according to the method for claim 1, it is characterised in that payment end is according to the plaintext dealing money and currency table The step of calculating the plaintext small change amount of money includes：

Payment end selects beneficiary to be handed over for the payment end and plaintext total amount more than or equal to the plaintext from currency table The digital cash and then composition currency subset of the easy amount of money, then the plaintext dealing money is subtracted to obtain with the plaintext total amount The plaintext small change amount of money.

7. according to the method for claim 6, it is characterised in that

The payment request includes transaction currency and small change currency, in the transaction currency comprising the ciphertext dealing money and First checking information, the ciphertext small change amount of money and second checking information are included in the small change currency；

The payment request also includes transfer data structure；

Before the step of end generation payment request of paying the bill, in addition to：

It is each in cryptographic Hash of the end generation comprising the transaction currency, the cryptographic Hash of the small change currency and the currency subset of paying the bill The transfer data structure of the cryptographic Hash of digital cash.

8. according to the method for claim 7, it is characterised in that

Before the step of node updates currency table according to the payment request, in addition to：Node is established for storing currency, currency The currency table of cryptographic Hash and the two corresponding relation；The currency table includes not spending currency table in currency table, confirmation Currency table is spent；

Before the step of payment request storage is arrived the block chain by node, in addition to：Node is according in the currency subset The cryptographic Hash of digital cash is searched and confirms that the digital cash in the currency subset does not spend currency table described in being stored in, with And confirm the ciphertext dealing money and the ciphertext small change amount of money and the ciphertext equal to digital cash in the currency subset Total amount.

9. use the transaction system of digital cash, it is characterised in that including：

Dealing money encrypting module, for being encrypted the plaintext dealing money received to obtain ciphertext dealing money；

First checking information generation module, for generating the first checking information for being used for verifying the ciphertext dealing money；

Small change amount of money computing module, for calculating the plaintext small change amount of money according to the plaintext dealing money and currency table；

Small change amount of money encrypting module, for the plaintext small change amount of money to be encrypted to obtain the ciphertext small change amount of money；

Second checking information generation module, for generating the second checking information for being used for verifying the ciphertext small change amount of money；

Payment request sending module, for generating payment request and broadcasting the payment request；The payment request includes institute State ciphertext dealing money, first checking information, the ciphertext small change amount of money and second checking information.

10. device according to claim 9, it is characterised in that the dealing money encrypting module is additionally operable to：

Generate the transaction private key that this payment uses；Basic point value is stored, and the basic point value is entered using basic point AES Row computations are to obtain basic point check value；The ciphertext dealing money is calculated according to formula q=xG+mH；Wherein, q is described Ciphertext dealing money, x are the transaction private key, and m is the plaintext dealing money received, and G is the basic point value, and H is described Basic point check value.

11. device according to claim 10, it is characterised in that first checking information, which includes the first transaction, to be proved；

The first checking information generation module is additionally operable to：The plaintext dealing money m is subjected to binary system according to presetting digit capacity n Split, to obtainWherein m_i=2ⁱOr m_i=0, i represent index bit, and 0≤i ＜ n；The transaction is private Key x is split at random according to presetting digit capacity n, to obtainWherein x₀To x_n-2Random generation,For each index bit, according to P (x_i,m_i)=x_iG+m_iH and P (x_i,m_i-k_i)=x_iG+(m_i-k_i)H Calculate P (x_i,m_i) and P (x_i,m_i-k_i)；Wherein k_i=2ⁱ；For index bit each described, the x is used_i, P (the x_i, m_i) and the P (x_i,m_i-k_i) generate the ring signatures S of the index bit_i；By the index bit of whole, the P (x_i,m_i), it is described P(x_i,m_i-k_i) and the S_iSpliced is proved with obtaining first transaction.

12. device according to claim 10, it is characterised in that first checking information includes the first communication information；

The first checking information generation module is additionally operable to：Generation payment end fixed private, gathering end fixed public is obtained, and Meter is encrypted to the product of the payment end fixed private and the gathering end fixed public using the basic point AES Calculate to obtain shared key, then spliced the plaintext dealing money and the transaction private key, reuse described shared Key spliced result is encrypted calculating to generate first communication information.

13. device according to claim 9, it is characterised in that the small change amount of money computing module is additionally operable to：Arranged from currency In table select beneficiary for it is described payment end and plaintext total amount more than or equal to the plaintext dealing money digital cash it is right Currency subset is formed afterwards, then subtracts the plaintext dealing money with the plaintext total amount to obtain the plaintext small change amount of money.

14. device according to claim 13, it is characterised in that the payment request includes transaction currency and small change goods Coin, the ciphertext dealing money and first checking information are included in the transaction currency, institute is included in the small change currency State the ciphertext small change amount of money and second checking information；

The payment request also includes transfer data structure；

Described device also includes：

Transfer data structural generation module, for cryptographic Hash of the generation comprising the transaction currency, the Hash of the small change currency The transfer data structure of the cryptographic Hash of each digital cash in value and the currency subset.

15. use the transaction system of digital cash, it is characterised in that including：

Payment request receiving module, for receiving payment request；The payment request includes ciphertext dealing money, the first checking letter Breath, the ciphertext small change amount of money and the second checking information；

Dealing money authentication module, for confirming that the ciphertext dealing money meets rule according to first checking information；

Small change amount of money authentication module, for confirming that the ciphertext small change amount of money meets rule according to second checking information；

Payment request enters chain module, for payment request storage to be arrived into block chain.

16. device according to claim 15, it is characterised in that

First checking information, which includes the first transaction, to be proved；

The dealing money authentication module is additionally operable to：Disassembling first transaction proves, to obtain whole index bit i, P (x_i, m_i)、P(x_i,m_i-k_i) and S_i；Confirm for index bit each described, the S_iFor the P (x_i,m_i) and the P (x_i,m_i- k_i) ring signatures, and confirm for index bit each described, meet P (x_i,m_i)-P(x_i,m_i-k_i)=k_iH, then confirm MeetTo confirm that the ciphertext dealing money meets rule；Wherein q is the ciphertext dealing money, k_i=2ⁱ。

17. device according to claim 15, it is characterised in that described device also establishes module and goods including currency table Coin list verification module, wherein,

The currency table establish module be used for establish be used for store currency, currency cryptographic Hash and the two corresponding relation currency arrange Table；The currency table includes not spending currency table in currency table, confirmation and has spent currency table；

The payment request includes transaction currency and small change currency, in the transaction currency comprising the ciphertext dealing money and First checking information, the ciphertext small change amount of money and second checking information are included in the small change currency；

The transfer data structure, which includes the cryptographic Hash of the transaction currency, the transfer data structure, also includes small change currency The cryptographic Hash of digital cash in cryptographic Hash and the currency subset；

The currency table authentication module is used for：Searched according to the cryptographic Hash of digital cash in the currency subset and described in confirming Currency in currency subset does not spend currency table described in being stored in, and confirms that the ciphertext dealing money is looked for the ciphertext Fractionl amount and the ciphertext total amount equal to digital cash in the currency subset.

18. a kind of computer-readable recording medium, computer instruction is stored with the computer-readable recording medium, its feature It is, the computer instruction can be run by computer or computer system, so that the computer or computer system energy Enough perform claims require the method any one of 1-8.