WO2021144888A1

WO2021144888A1 - Settlement processing device, settlement processing program, and settlement processing system

Info

Publication number: WO2021144888A1
Application number: PCT/JP2020/001114
Authority: WO
Inventors: 玲大塚; 大成高橋
Original assignee: 株式会社ＦｉｎａｌｉｔｙＴｅｃｈｎｏｌｏｇｉｅｓ
Priority date: 2020-01-15
Filing date: 2020-01-15
Publication date: 2021-07-22

Abstract

A settlement processing device according to one embodiment of the present invention comprises a generation unit, a signature unit, and a certification unit. The generation unit generates a transaction relating to a deal. The signature unit affixes a digital signature to the transaction using a first secret key. The certification unit certifies authenticity of the transaction by affixing a digital signature using a second secret key corresponding to a second public key authenticated by a reliable third party in the deal.

Description

Payment processing device, payment processing program and payment processing system

The present invention relates to a payment processing device, a payment processing program, and a payment processing system.

In a transaction using a blockchain represented by a cryptocurrency, it takes a considerable amount of time from the occurrence of the transaction to the approval of the transaction, that is, the completion of settlement. In the case of Bitcoin (registered trademark), there is a time lag of nearly one hour from the time a transaction is generated until the settlement is completed. Therefore, for example, assuming that a cryptocurrency is used for payment for purchasing a product at a physical store, a cryptocurrency that takes one hour to settle is not realistic as a payment method. That is, there is a problem that it is difficult to introduce the daily use of settlement transactions using the blockchain.
Therefore, it is desirable to shorten the time to payment and realize immediate payment with cryptocurrency, but with the above-mentioned blockchain mechanism, if you try to make immediate payment forcibly, the same coin will be used twice. Payment problems may occur.
As a countermeasure against the double payment problem that is conscious of such immediate settlement, there is a method of extracting the area around the block including the deposit transaction of the main blockchain as a subchain and having the wallet side of the cryptocurrency confirm the deposit (for example). Non-Patent Document 1).

However, in Non-Patent Document 1, it is necessary to accurately measure the time required to generate the subchain, and a reliable time stamp server is required. Alternatively, there is a method of setting an expiration date for the deposited coins and making the deposited coins unusable after a certain period of time, thereby eliminating the need for a reliable time stamp server, but in this case, there is a problem of lack of usability. ..

The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to be able to execute an immediate settlement or an immediate contract using a blockchain.

In order to solve the above-mentioned problems, the payment processing device according to the present embodiment includes a generation unit, a signature unit, and a certification unit. The generator generates a transaction related to the transaction. The signing unit digitally signs the transaction using the first private key. The proof unit certifies the authenticity of the transaction by digitally signing it with a second private key corresponding to the second public key authenticated by a trusted third party in the transaction.

According to the payment processing device of the present invention, immediate payment or immediate contract using the blockchain can be executed.

The block diagram which shows the payment processing apparatus of the payment side which concerns on this embodiment. The block diagram which shows the payment processing apparatus of the receiving side which concerns on this Embodiment. The flowchart which shows the payment processing in the payment processing apparatus of the payment side which concerns on this embodiment. The sequence diagram which shows the payment processing in the payment processing apparatus of the receiving side which concerns on this Embodiment. The sequence diagram which shows the redemption processing of the cryptocurrency in the payment processing apparatus of the receiving side which concerns on this Embodiment.

Settlements and contracts using blockchain (so-called smart contracts) represented by cryptocurrencies are in a state where transactions are not overturned through the following two events after an agreement is reached between the parties and issued. It has reached (also called finality), and this state is said to be the state in which the transaction has been approved (also called confirmation).
The first event is that the transaction related to the transaction is captured in the block. The second event is that a sufficient number or more of new blocks are added after the block. In the case of Bitcoin, which is a type of cryptocurrency, the sufficient number of blocks of a predetermined number or more may be 5 or 6 blocks. This is because Bitcoin adds one block to the blockchain every 10 minutes, so considering the current difficulty of mining and the computing power of the computer used for mining, it is safe enough to prevent fraud. No, it can be considered as a sufficient number of blocks. On the other hand, assuming that the transaction is approved when 6 blocks are added, it takes 10 minutes x 6 = 60 minutes to settle, so it is difficult to introduce it as a daily settlement method as it is.
According to the payment processing device, the payment processing program, and the payment processing system according to the present embodiment, it is possible to make an immediate payment or an immediate contract with almost no change in the existing blockchain mechanism.

Hereinafter, the payment processing device, the payment processing program, and the payment processing system according to the embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, it is assumed that the same operation is performed for the parts with the same number, and the description thereof will be omitted.

In this embodiment, a case where a cryptocurrency represented by Bitcoin (registered trademark) is settled using a blockchain network in which a transaction history is recorded will be described as an example. The payment method is not limited to cryptocurrency, and may be a payment method that can be converted into money such as electronic money, virtual money, and points provided by each company's point service. Similarly, the payment processing device, payment processing program, and payment processing system according to the present embodiment can be applied to smart contracts that realize transactions such as transfer of real estate such as land and insurance contracts on the blockchain.

The payment processing device on the payment side of the cryptocurrency according to the present embodiment will be described with reference to the block diagram of FIG. The payment processing device on the payment side is also called a payment device.

The payment processing device 1 on the paying side according to the present embodiment may have tamper resistance due to hardware and / or software. Having tamper resistance by hardware includes a case where only the payment processing device 1 is configured to have tamper resistance and a case where the device having tamper resistance includes the payment processing device 1.
For example, the payment processing device 1 may be stored in tamper-resistant hardware represented by a secure element such as SIM (Subscriber Identity Module) or USIM (Universal SIM). In addition to secure elements, there are secure mechanisms such as TrustZone (registered trademark) of ARM (registered trademark) and Intel SGX of Intel (registered trademark). The payment processing device 1 may be stored in the hardware having the payment processing device 1.
When the software is considered to have tamper resistance due to obfuscation or the like, the payment processing device 1 may be realized by the software.

The payment processing device 1 includes a processing circuit 11, a memory 12, and a communication interface 13. The processing circuit 11 includes a management unit 111, a generation unit 112, a signature unit 113, a certification unit 114, and a transmission / reception unit 115. The processing circuit 11 is composed of one processing circuit such as a CPU (Central Processing Unit) or GPU (Graphics Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). The processing circuit 11, the memory 12, and the communication interface 13 are connected to each other via a bus so that data can be transmitted and received. Not limited to this, each part may be configured as a single processing circuit or a single integrated circuit.

The management unit 111 includes a private key (also referred to as a first private key) generated by the user and a public key (first public key) corresponding to the first private key included in the cryptographic currency wallet stored in the memory 12 described later. Manage one or more pairs (also called keys). The management unit 111 manages one or more accounts based on the public key and the balance corresponding to each of the one or more accounts. In the case of a system such as Bitcoin that does not allow division of the balance (UTXO: Unspent Transaction Output), the balance takes only two values, the deposit amount (unused) and 0 (used). The management unit 111 trusts the public key (also referred to as the second public key) authenticated by a third party trusted in the transaction and the private key corresponding to the second public key (the second private key or the transaction of the cryptocurrency). It manages a pair with a private key authenticated by a third party.
The trusted third party in the transaction is, in the present embodiment, the third party trusted in the cryptocurrency transaction, for example, the manufacturer of hardware or software that realizes the tamper resistance as described above. A service provider. In the case of a transaction other than cryptocurrency, for example, a smart contract assuming a real estate transaction, the third party trusted in the transaction may be a management company that manages the tokenized real estate.
In the authentication of the second public key by a third party trusted in the transaction, for example, in the payment processing device 1, the user generates the second private key and the corresponding second public key, and the second public key is encrypted. Authentication may be realized by issuing a certificate of a trusted third party in currency transactions.
In addition, a third party (for example, a manufacturer) trusted in the transaction generates a second private key and a corresponding second public key in advance, and issues a third party certificate at the same time. A trusted third party in the transaction stores the second private key, the corresponding second public key and the certificate in the tamper-resistant hardware in advance, so that the trusted third party can perform the second. Public key authentication may be realized.

The generation unit 112 generates a transaction related to a cryptocurrency transaction.
The signing unit 113 digitally signs the transaction using the first private key.
The proof unit 114 proves the authenticity of the transaction by digitally signing it with the second private key. The specific processing of the certification unit 114 will be described later.
The transmission / reception unit 115 receives information such as a public key and a requested amount from the receiving side, and transmits a transaction or the like.

The memory 12 stores the wallet of the paying user. The wallet includes a pair of a first private key and a first public key, and a pair of a second private key and a second public key. The memory 12 is composed of a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), and an integrated circuit storage device.

The communication interface 13 is an interface for transmitting and receiving data between the payment processing device 1 and the external device, which conforms to a predetermined communication standard. Communication standards include mobile networks such as 4G and 5G, wireless LANs such as Wi-Fi (registered trademark), wireless networks such as Bluetooth (registered trademark) and NFC (Near Field Communication), or LAN and USB (Universal Serial Bus). ) And other wired networks are assumed.

Next, the payment processing device on the receiving side of the cryptocurrency according to the present embodiment will be described with reference to the block diagram of FIG. The payment processing device on the receiving side is also called a payment device.
The payment processing device 2 on the receiving side may also have tamper resistance like the payment processing device 1 on the payment side.

The payment processing device 2 on the receiving side includes a processing circuit 21, a memory 22, and a communication interface 23. The processing circuit 21 includes a management unit 211, a transmission / reception unit 212, a verification unit 213, a reception unit 214, a generation unit 215, and a signature unit 216.

Management unit 211 manages the local blockchain, which is all or part of the blockchain. The local blockchain is the latest blockchain at the time when the payment processing device 2 is last connected to the network. In general, the latest blockchain may not reach an agreement from the latest block to a predetermined number of past blocks due to a phenomenon called a fork. However, if the blockchain is operating normally, it can be considered that a complete agreement has been reached for the blockchain (prefix) obtained by excluding a predetermined number of past blocks from the latest block.
The transmission / reception unit 212 receives the second public key and the payment transaction related to the payment transaction. Further, in the case of the redemption process described later, a redemption transaction for compensating for the loss is transmitted.

The verification unit 213 verifies whether the balance of the payment source is equal to or greater than the payment amount, the payment transaction is valid, and the source of the payment transaction is reliable.
The receiving unit 214 can determine that the payment transaction is subsequently approved by the blockchain if the payment source balance is greater than or equal to the payment amount, the payment transaction is valid, and the payment transaction is reliable to prove the source of the payment transaction. , Accept the transaction shown in the payment transaction. After being accepted by the receiving unit 214, the user on the receiving side of the cryptocurrency may execute the contract according to the transaction content of the payment transaction, or the external executing unit executes the accepted transaction. You may.

The generation unit 215 generates a redemption transaction in the redemption process described later.
The signing unit 216 digitally signs the redemption transaction with the private key contained in the wallet stored in the memory 22.

The memory 22 stores the blockchain acquired at the time of the latest network connection with the wallet of the receiving user as a local blockchain. The wallet contains a pair of a private key (also referred to as a third private key) generated by the receiving user and a public key (also referred to as a third public key) corresponding to the third private key.
Since the communication interface 23 is the same as the communication interface 13, a specific description thereof will be omitted.

The payment processing device on the payment side shown in FIG. 1 and the payment processing device on the receiving side shown in FIG. 2 may be configured as one payment processing device including the respective configurations shown in FIGS. 1 and 2. In this case, if the payment processing device operates as the paying side, the configuration shown in FIG. 1 may function, and if the payment processing device operates as the receiving side, the configuration shown in FIG. 2 may function.

Next, the payment processing of the cryptocurrency related to the payment processing device 1 on the payment side according to the present embodiment will be described with reference to the flowchart of FIG.
In the present embodiment, the wallet W may be stored in the memory 12 of the payment processing device 1 or may be stored in an external device (not shown). In the following, it is assumed that the cryptocurrency is transferred from the user's wallet W to the new account w, and the balance of the wallet W is assumed to be zero or more.

In step S301, the generation unit 112 generates an account w corresponding to a new pair of the first private key and the first public key. The account w is an address represented by a character string. For example, if the hash value of the first public key is calculated and the hash value is encoded into a character string in an encoding format such as Base58Check, the character string is defined as the account w. good.
In step S302, the wallet W generates a _{deposit transaction τ l} relating to a deposit transaction for transferring a _{cryptocurrency of an amount bl to a new account w.} The deposit transaction τ _l provides information on the source account of the cryptocurrency (here, the address of the wallet W), the destination account of the cryptocurrency (here, the address of the account w), and the amount to be transferred (here, b _l ). include.

In step S303, the wallet W _{digitally signs the deposit transaction τ l} with the first private key. By digitally signing with the first private key, the deposit transaction τ _l becomes valid.
In step S304, the wallet W _{broadcasts the deposit transaction τ l} to the blockchain network.
In step S305, the wallet W acquires _{block B i from the blockchain network.}

In step S306, determines wallet W is, whether the payment transaction tau _l is approved, that is, whether the acquired block B _i in the deposit transaction tau _l is incorporated. Specifically, for example, if the block B _i is only to include the transaction set information Merkle tree, by calculating the Merkle root and Makurupasu blocks B _i, the existing method, payment transactions in the block B _i It can be determined whether or not _{τ l is included.}
If taken by the obtained block B _i in the deposit transaction tau _l, the process proceeds to step S307, if not captured payment transaction tau _l to the obtained block B _i, and repeats the same processing returns to step S305.

In step S307, the wallet W is credited transaction tau _l to produce a deposit certificate tau _l ^* to indicate that are incorporated in the block B _i. Deposit credentials tau _l ^* is an auxiliary information to prove that tau _l is included in the set of transactions with block B _i (witness).
The deposit proof information τ _l ^* is, for example, a set of hash values of the clauses that are siblings in each clause in the route from the Merkle root in the Merkle tree to the Merkle _{leaf indicating the deposit transaction τ l.} The deposit proof information τ _l ^* may be Witness in the zero-knowledge proof. By using the deposit proof information τ _l ^* , the membership check function of Eq. (1) can be defined, and the membership proof indicating that the transaction is included in the block can be realized.

member (B, τ _l , τ _l ^* ) = 1 (if τ _l ∈ B) otherwise 0 (1)
In step S308, the payment processing device 1 receives (B, τ _l , τ _l ^* ) at the transmission / reception unit 115 via the communication interface 13, and member (B, τ _l , τ _l ^* ) = at the proof unit 114. Only when 1 is confirmed, the management unit 111 stores the pair (τ _l , τ _l ^* _{) of the deposit transaction τ l} and the deposit proof information τ _l ^* in the memory 12.
In step S309, the management unit 111 updates the balance of the account w. Here, in accordance with the payment transaction τ _l, the balance of the account w is set to b _l.

Note that the cryptocurrency deposit for one account is not limited to one time, and the cryptocurrency may be deposited multiple times for one account. Also, withdrawal of cryptocurrency from one account is not limited to those that can be withdrawn multiple times as long as there is a balance, and even if withdrawal of cryptocurrency from one account is limited to only once. good.

Next, the payment processing of the payment processing device 2 on the receiving side according to the present embodiment will be described with reference to the flowchart of FIG. The payment process shown in FIG. 4 can be executed offline between the payment processing device 1 (X) on the paying side and the payment processing device 2 (Y) on the receiving side. A payment processing system can be realized by the payment processing device 1 and the payment processing device 2 shown in FIG.

In step S401, for example, from the transmission / reception unit 212 of the payment processing device 2 on the receiving side, the account y corresponding to the third public key PKy on the receiving side and the requested amount b _{0 of the} cryptocurrency are set on the paying side via the communication interface 13. Is transmitted to the payment processing device 1.
In step S402, the management unit 111 of the payment processing device 1 on the payment side confirms the balance of the account w. In this case, the balance _{b l} of account w is _{b 0} or more, and that is, _{_b l} ≧ _b _0. If the balance is _{less than b 0} , the process ends. However, if the payment processing device 1 manages a plurality of accounts and the total balance is b ₀ or more, the payment is processed as payment from the plurality of accounts.

In step S403, the management unit 111 of the payment processing device 1 on the payment side calculates a new balance obtained by subtracting _{b 0 from the balance of the account w.}
In step S404, the generation unit 112 of the payment processing device 1 on the paying side generates _{a payment transaction τ 0} indicating the content of paying the _{cryptocurrency} of bo from the account w to the receiving side. Further, the generation unit 112 generates payment proof information including payment information regarding the account w. The payment proof information may be a pair of _{deposit transaction τ l} and deposit proof information τ _l ^* _{(τ l} , τ _l ^* ), and further includes _{payment transaction τ 0} when efficiency is required on the receiving side. It may be a set (τ ₀ , τ _l , τ _l ^*).

In step S405, the signature unit 113 of the payment processing device 1 on the payment side digitally signs _{the payment transaction τ 0} with the first private key sk _w.
In step S406, the proof unit 114 of the payment processing device 1 on the payment side digitally signs _{the payment proof information with the second private key sk T.}

_{In step S407, the digitally signed payment transaction τ 0} and the digitally signed payment proof information are transmitted to the receiving side payment processing device 2 via the transmission / reception unit 115 and the communication interface 13 of the payment processing device 1 on the paying side. do. Incidentally, from the settlement processing unit 1 of the payment side, with respect to the payment processing apparatus 2 receiving the certificate for the second public key PK _T of a trusted third party issues the transaction encryption currencies are transmitted together You may.

In step S408, the verification unit 213 of the payment processing device 2 on the receiving side executes the verification process. Specifically, it is determined whether or not all of the following three requirements are satisfied.
(A) The deposit transaction τ _l is taken into the block B, and the deposit transaction τ _l is approved by the blockchain network.
(B) The payment transaction τ ₀ digitally signed with the first private key sk _w is valid.
(C) The payment proof information digitally signed with the second private key sk _T is valid as proof from a device authenticated by a trusted third party in cryptocurrency transactions.

The requirement (a), the verification unit 213, in the block chain C _Y in the local settlement processing unit 2, whether or not include blocks including the payment transaction tau _l (i.e., tau _l ∈ C _Y ^{" k} is whether) to confirm. in this case, if holding the blocks of the block chain C _Y to include a hash value indicating the Merkle root represent the transaction in the form of a Merkle tree, block chain Therefore, it is not necessary to maintain all transactions of the deposit transaction τ _{l in} terms of memory and processing amount. For example, the verification unit 213 can verify the hash value of the Merkle tree of the block and the payment proof. It can be determined that the requirement (a) is satisfied by comparing and calculating the hash values from the Merkle root included in the information to the Merkle _{leaf indicating the deposit transaction τ l, which are concatenated and summarized.}

In (b), the digital signature is performed by the first secret key sk _w, and, if so account balance w does not become negative in the light of the block chain C _Y in the payment transaction tau ₀ local, of (b) It can be determined that the requirements are met.

(C), the digital signature of the second secret key sk _T can be verified by the second public key PK _T, and certificate for the second public key PK _T a third party is issued that is trusted in the transaction of encryption currency such as If it can be verified that the second public key PK _T is valid, it can be determined that the requirement (c) is satisfied.

When the verification unit 213 can verify that all the above requirements (a) to (c) are satisfied, the payment source account also has a balance, and the payment transaction τ ₀ generated from a reliable wallet. , It can be determined that the payment transaction τ ₀ is a transaction that is subsequently approved in the blockchain. That is, it can be determined that the payment transaction τ ₀ can be accepted immediately.

On the other hand, if even one of the above requirements (a) to (c) is not satisfied, it cannot be determined that the payment transaction τ ₀ is legitimate but immediately acceptable, or it is considered to be a fraudulent transaction. .. Therefore, immediate acceptance is abandoned, and if the payment transaction τ ₀ is a legitimate transaction, it is broadcast to the blockchain network as a normal transaction. Here, it is assumed that the payment transaction τ ₀ can be immediately accepted, and then it is determined that the transaction is approved in the blockchain.

In step S409, the receiving unit 214 of the payment processing device 2 on the receiving side accepts the transaction _{shown in the payment transaction τ 0} , and the immediate settlement or the immediate contract is executed. For example, the vending machine may be set to discharge the goods specified by the user after the payment in the cryptocurrency is received in the vending machine in step S409.

When the receiving side payment processing device 2 accepts the transaction, the paying side payment processing device 1 may notify the payment side payment processing device 1 that the transaction has been accepted and the payment or contract has been completed. Further, the payment processing device 2 on the receiving side may notify that the payment transaction τ ₀ cannot be immediately accepted when the transaction is not accepted, that is, when the payment transaction τ _{0 is determined to be unacceptable immediately.}

Incidentally, the verification unit 213, when verifying the requirements of (1) in step S408, block the latest block of a predetermined number of blocks of the block chain C _Y in the local k (k is a natural number) (end of block) It may be confirmed by the deposit proof information that the _{deposit transaction τ l} is included in the remaining blockchain removed from. This processing in step S408 is because it is assumed the process off-line, block chain C _Y are acquired locally might not be up to date. Also, a few blocks at the end of the block chain C _Y are acquired locally, depending on the state of the block chain network because it may not have been achieved agreed influence of forks, it is included in the block deposit This is because the transaction τ _l may not be approved.

_{On the other hand, if the deposit transaction τ l} is included in the block before a predetermined period from the present, the _{probability that the deposit transaction τ l} is not approved without overturning the transaction can be reduced as much as possible according to k. _{That is, if the block containing the deposit transaction τ l} is incorporated in the remaining blockchain from which k blocks have been removed, it can be said that the reliability of the transaction is sufficiently high. The value of the predetermined number k may be set to "k = 6", which is the number of blocks generally considered to maintain the main chain of the blockchain in Bitcoin, or a transaction. It may be decided according to the amount of. For example, k may be set to a large value so that the larger the transaction amount of the payment transaction, the higher the possibility that the block is incorporated into the blockchain (transaction reliability).

Next, the redemption process of the cryptocurrency in the payment processing device 2 on the receiving side will be described with reference to the flowchart of FIG. Here, even though the payment transaction τ ₀ is actually invalid, the condition in step S408 described above is satisfied. Therefore, if the receiving side makes an immediate settlement or an immediate contract and a loss occurs, the loss is compensated. If this is the case. Here, the company that compensates for the loss may be a third party trusted in a transaction such as a manufacturer that manufactures a device for storing a wallet, or a company such as an insurance company that specializes in compensation.

In step S501, the transmission / reception unit 212 of the payment processing device 2 on the receiving side broadcasts the _{payment transaction τ 0 to the blockchain network.}
In step S502, the management unit 211 of the payment processing device 2 on the receiving side monitors the blockchain network and updates the block B of the local blockchain it owns.

At step S503, determines the verification unit 213 of the recipient of the payment processing apparatus 2, or payment transaction tau ₀ is approved at block chain network, or payment transaction tau ₀ is invalid. If the payment transaction τ ₀ is approved in the blockchain network, it becomes the process of receiving the cryptocurrency by the normal transaction. Here, it is assumed that the payment transaction τ ₀ is invalid.
In step S504, generation unit 215 of the settlement processing unit 2 of the receiving side, for performing the redemption process to generate a redemption transaction tau _r. The redemption transaction τ _r includes payment proof information and payment transaction τ ₀ , and proves the validity that the payment processing device 2 immediately accepts the payment transaction τ _0.

In step S505, generation unit 215 of the settlement processing unit 2 of the receiving side, digitally signed with the third secret key to the redemption transaction tau _r.
At step S506, the settlement processing unit 2 of the transmitting and receiving unit 212 of the receiving side transmits a digitally signed redeemed transaction tau _r to compensate skilled T.

In step S507, the compensation trader T is, to investigate the redemption transaction τ _r. Here, the contents of the redemption transaction tau _r is determined to be valid.
In step S508, the compensating _{transaction T} generates a compensating transaction τ _{T to compensate for the receiving loss bo.}
In step S509, the compensating transaction _T broadcasts the compensating transaction τ T to the blockchain network. If the compensating transaction τ _T is authentic, then the compensating transaction τ _T is approved by the blockchain network and the cryptocurrency is compensated to the recipient.

According to the present embodiment shown above, the payer pays using a second private key authenticated by a trusted third party in the transaction, such as the manufacturer of the tamper resistant device that stores the wallet. Digitally sign the credentials. The recipient accepts the payer's transaction if it is confirmed that the payment proof information is signed with a key authenticated by a trusted third party in the transaction and meets certain conditions.
This makes it possible to execute instant payments and instant contracts without modifying the blockchain network represented by cryptocurrencies such as Bitcoin. In addition, since the authenticity of the transaction is verified by the receiving side, the wallet on the paying side does not need to store the blockchain for verification in the wallet. Therefore, on the payment side, a time stamp server for verifying the blockchain is unnecessary, and a lightweight tamper-resistant wallet can be realized without the restriction that the wallet cannot be used after a certain period of time has passed since the payment was made.

In addition to the above-mentioned examples of use of the payment processing device 1, the payment processing device 2, and the payment processing system according to the present embodiment, a cryptocurrency can be used for payment at a convenience store cash register. It can also be applied when receiving digital contents or digital services via the Internet.
In addition, even when securities transactions or derivative transactions are conducted via the Internet, immediate transactions can be completed without depositing deposits with a securities company. It is also possible to purchase insurance products via the Internet immediately before the user's actions. It can also be applied to the purchase of speed lottery, etc., where the winning is found on the spot. In addition, the settlement processing system according to the present embodiment can be introduced for transactions that require immediate completion.

The instructions given in the processing procedure shown in the above-described embodiment can be executed based on a program that is software. It is also possible for a general-purpose computer system to store this program in a recording medium in advance and read the stored program to obtain an effect similar to the effect of the identification device described above. Further, the recording medium in the present embodiment is not limited to a medium independent of the computer or the embedded system, but also includes a recording medium in which a program transmitted by a LAN, the Internet, or the like is downloaded and stored or temporarily stored.

The invention of the present application is not limited to the above-described embodiment, and can be variously modified at the implementation stage without departing from the gist thereof. In addition, each embodiment may be carried out in combination as appropriate as possible, and in that case, the combined effect can be obtained. Further, the above-described embodiment includes inventions at various stages, and various inventions can be extracted by an appropriate combination in a plurality of disclosed constitutional requirements.

1, 2, ...

Payment processing device

11, 21, ... Processing

circuit

12, 22 ...

Memory

13, 23 ...

Communication interface

111, 211 ...

Management unit

112, 215 ...

Generation unit

113, 216 ... Signature unit 114 ...

Certification unit

115, 212 ... Transmission / reception unit 213 ... Verification unit 214 ... Reception unit

Claims

A generator that generates transactions related to transactions, and
A signature unit that digitally signs the transaction using the first private key,
A proof unit that proves the authenticity of the transaction by digitally signing it with a second private key that corresponds to the second public key authenticated by a trusted third party in the transaction.
A payment processing device comprising.
When the transaction is a payment transaction related to a payment transaction from the first account, the signing unit digitally signs the payment transaction using the first private key.
The payment processing device according to claim 1, wherein the proof unit digitally signs payment proof information including payment information related to the first account using the second private key.
The payment proof information includes information including a deposit transaction related to a deposit transaction to the first account and deposit proof information indicating that the deposit transaction is incorporated in a block of a blockchain in which a transaction history is recorded, or information. The payment processing device according to claim 2, which is information including a payment transaction digitally signed with the first private key, the deposit transaction, and the deposit proof information.
It further has a management unit that manages one or more accounts and the balance corresponding to each of the one or more accounts.
The management department
If there is a deposit transaction related to the deposit transaction to the first account, the set of the deposit proof information indicating that the deposit transaction is incorporated in the block of the blockchain in which the transaction history is recorded and the deposit transaction are retained. ,
The settlement processing device according to any one of claims 1 to 3, which updates the balance of the first account based on the content of the deposit transaction.
The block contains Merkle tree format information that identifies a set of transactions contained within the block.
The deposit transaction is one of the Merkle leaves in the Merkle tree.
The payment processing device according to claim 4, wherein the deposit proof information includes a set of hash values in the route from the Merkle leaf to the Merkle route corresponding to the deposit transaction.
The payment processing device according to any one of claims 1 to 5, which has tamper resistance.
A management department that manages all or part of the blockchain where transaction history is recorded,
A trusted third party public key in a transaction, a digitally signed payment transaction for a payment transaction from the payment source's first account, and a digitally signed deposit information for the payment source account of the payment transaction. A receiver that receives payment proof information, including
If the payment transaction is valid in the light of the blockchain, the digital signature of the payment transaction is valid, and the digital signature on the payment proof information can be verified to be authentic based on the public key, then the payment transaction The receiving department that accepts the transactions shown in
A payment processing device comprising.
The payment proof information includes a deposit transaction related to a deposit transaction to the first account and a deposit proof information indicating that the deposit transaction is incorporated in a block of the blockchain.
Further provided is a verification unit that verifies that the deposit transaction is included in the remaining blockchain obtained by removing a predetermined number of blocks from the end of the blockchain managed by the management unit by using the deposit proof information. death,
The settlement processing device according to claim 7, wherein the receiving unit accepts the transaction shown in the payment transaction when it can be verified that the deposit transaction is included in the remaining blockchain.
On the computer
A generation function that generates transactions related to transactions, and
A signature function that digitally signs the transaction using the first private key,
A proof function that proves the authenticity of the transaction by using the second private key corresponding to the second public key authenticated by a trusted third party in the transaction.
Payment processing program to realize.
On the computer
The acquisition function to acquire the public key of a third party trusted in the transaction and the digitally signed payment transaction related to the payment transaction from the first account of the payment source.
A payment proof that includes payment information about the payment transaction is valid, the digital signature of the payment transaction is valid, and the account from which the payment transaction is paid is in light of all or part of the blockchain in which the transaction history is recorded. A verification function that verifies whether the digital signature of the information is authentic based on the public key,
If the verification by the verification function is successful, the acceptance function for accepting the transaction shown in the payment transaction and the acceptance function
Payment processing program to realize.
A payment processing system that includes a payment device on the paying side and a payment device on the receiving side.
The payment device
A generator that generates payment transactions related to payment transactions from the first account,
A signature unit that digitally signs the payment transaction using the first private key,
A proof unit that digitally signs payment proof information including payment information related to the first account using a second private key corresponding to a second public key authenticated by a third party trusted in the transaction.
Equipped with
The payment device is
A management department that manages all or part of the blockchain where transaction history is recorded,
A receiving unit that receives the public key corresponding to the second private key, the digitally signed payment transaction, and the digitally signed payment proof information.
If the payment transaction is valid in the light of the blockchain, the digital signature of the payment transaction is valid, and the digital signature on the payment proof information can be verified to be authentic based on the public key, then the payment transaction The receiving department that accepts the transactions shown in
A payment processing system equipped with.