Information processing system, information processing method, and node device

Abstract

In an information processing system 1, a plurality of node devices having a plurality of wallets communicate according to a peer-to-peer method, thereby recording, in a distributed ledger composed of a block chain, transaction information representing the transfer of a token associated with a coin between two wallets. A first node device having a first wallet generates new transaction information indicating the transfer of a token from the first wallet to a second wallet, and transmits, to a second node device having the second wallet, the new transaction information and transaction history information that includes a transaction information group corresponding to the history of transferring of the token from the issuance of the token to the transfer immediately before the transfer represented by the new transaction information. The second node device verifies, on the basis of the new transaction information and the transaction history information, that the transfer of the token is a valid transfer of the token issued by the genuine issuer.

Description

Technical Field

[0001] The present invention relates to an information processing system, an information processing method, and a node device.

Background Art

[0002] There is known an information processing system in which a plurality of node devices each having a plurality of wallets communicate according to a peer-to-peer method, and transaction information representing the transfer of tokens associated with coins between two of the plurality of wallets is recorded in a distributed ledger constituted by a blockchain.

[0003] By the way, when the transaction information is recorded in the distributed ledger, although it is verified that the transfer of the coins represented by the transaction information is a valid transfer of the coins issued by the true issuer, it is not verified that the transfer of the tokens represented by the transaction information is a valid transfer of the tokens issued by the true issuer (in other words, the validity of the token transfer).

[0004] Therefore, for example, the information processing system described in Patent Document 1 includes a management device that verifies the validity of token transfers.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the management device cannot verify the validity of token transfers unless it extracts the transaction information related to tokens from all the transaction information recorded in the distributed ledger.

[0007] Incidentally, the amount of transaction information recorded in a distributed ledger is considerably larger than the amount of transaction information related to tokens. Therefore, the burden of extracting token-related transaction information from all the transaction information recorded in the distributed ledger is excessive. Thus, the above information processing system had the problem of an excessive load on verifying the validity of token transfers. This problem could also arise if node devices were used to verify the validity of token transfers instead of the management device.

[0008] One of the objectives of the present invention is to reduce the burden of verifying the validity of token transfers. [Means for solving the problem]

[0009] In one aspect, the information processing system records transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, through peer-to-peer communication between multiple node devices, each having multiple wallets.

[0010] The first node device having the first wallet comprises a generation unit and a transmission unit. The generation unit generates new transaction information, which is transaction information representing the transfer of tokens from the first wallet to the second wallet. The transmitting unit transmits the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the token's transfers from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet.

[0011] The second node device comprises a receiving unit and a verification unit. The receiving unit receives new transaction information and transaction history information. The verification unit performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer.

[0012] In another aspect, the information processing method involves multiple node devices, each having multiple wallets, communicating in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets on a distributed ledger composed of a blockchain.

[0013] Information processing methods are The first node device having the first wallet generates new transaction information, which is transaction information representing the transfer of tokens from the first wallet to the second wallet. The first node device transmits to the second node device having the second wallet the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the token's transfers from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, associated with the order of transfers in that history. The second node device receives new transaction information and transaction history information. The second node device performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer. This includes the following.

[0014] In another aspect, a node device has a first wallet in an information processing system in which multiple node devices, each having multiple wallets, communicate in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain.

[0015] The node device comprises a generation unit and a transmission unit. The generation unit generates new transaction information, which is transaction information representing the transfer of tokens from the first wallet to the second wallet. The transmitting unit transmits the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the token's transfers from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet.

[0016] In another aspect, a node device has a second wallet in an information processing system in which multiple node devices, each having multiple wallets, communicate in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain.

[0017] The node device comprises a receiving unit and a verification unit. The receiving unit receives from the first node device having the first wallet new transaction information, which is transaction information representing the transfer of a token from the first wallet to the second wallet, and transaction history information, which includes a group of transaction information corresponding to the history of the transfer of the token from when the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history. The verification unit performs token transfer verification to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer, based on the received new transaction information and the received transaction history information.

Advantages of the Invention

[0018] It is possible to suppress the load for verifying the validity of the token transfer.

Brief Description of the Drawings

[0019] [Figure 1] It is a block diagram showing the configuration of the information processing system according to the first embodiment. [Figure 2] It is a block diagram showing the configuration of the node device according to the first embodiment. [Figure 3] It is a block diagram showing the functions of the node device according to the first embodiment. [Figure 4] It is a block diagram showing a part of the functions of the granting node device and a part of the functions of the receiving node device according to the first embodiment. <s [Figure 5] It is a sequence diagram showing an example of the operation of the information processing system according to the first embodiment. [Figure 6] It is a flowchart showing the granting time process executed by the granting node device according to the first embodiment. [Figure 7] It is a flowchart showing the receiving time process executed by the receiving node device according to the first embodiment. [Figure 8] It is a flowchart showing the token transfer verification executed by the receiving node device according to the first embodiment. [Figure 9] It is a flowchart showing the record verification executed by the receiving node device according to the first embodiment. [Figure 10] It is a flowchart showing the continuous verification executed by the receiving node device according to the first embodiment. [Figure 11] It is a flowchart showing the issuance verification executed by the receiving node device according to the first embodiment. [Figure 12]This is a flowchart illustrating the rule verification performed by the receiving node device in the first embodiment. [Figure 13] This is a block diagram showing the function of the node device of the first modified example of the first embodiment. [Figure 14] This is a flowchart showing the receiving process performed by the receiving node device of the first modified embodiment of the first embodiment. [Figure 15] This is a flowchart showing the issuance verification performed by the receiving node device in the first modified example of the first embodiment. [Figure 16] This is a flowchart illustrating the rule verification performed by the receiving node device in the first modified example of the first embodiment. [Figure 17] This is a block diagram showing the function of a node device in a second modified example of the first embodiment. [Figure 18] This is a flowchart showing the receiving process performed by the receiving node device of the second modified embodiment of the first embodiment. [Figure 19] This is a flowchart illustrating the token transfer verification performed by the receiving node device in the second modified example of the first embodiment. [Figure 20] This is a flowchart showing the verified determination performed by the receiving node device in the second modified example of the first embodiment. [Figure 21] This is a flowchart illustrating the record verification performed by the receiving node device in the second modified example of the first embodiment. [Figure 22] This is a flowchart showing the sequential verification performed by the receiving node device in the second modified example of the first embodiment. [Figure 23] This is a flowchart showing the issuance verification performed by the receiving node device in the second modified example of the first embodiment. [Figure 24] This is a flowchart illustrating the rule verification performed by the receiving node device in the second modified example of the first embodiment. [Figure 25] This is a sequence diagram illustrating an example of the operation of the information processing system in the second embodiment. [Figure 26] This is a flowchart showing the receiving process performed by the receiving node device of the second embodiment. [Modes for carrying out the invention]

[0020] Hereinafter, embodiments of the information processing system, information processing method, and node device of the present invention will be described with reference to Figures 1 to 26.

[0021] <First Embodiment> (overview) In the first embodiment, the information processing system records transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, by having multiple node devices, each having multiple wallets, communicate in a peer-to-peer manner.

[0022] The first node device having the first wallet comprises a generation unit and a transmission unit. The generation unit generates new transaction information, which is transaction information representing the transfer of tokens from the first wallet to the second wallet. The transmitting unit transmits the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the token's transfers from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet.

[0023] The second node device, which has a second wallet, comprises a receiving unit and a verification unit. The receiving unit receives new transaction information and transaction history information. The verification unit performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer.

[0024] According to this system, new transaction information and transaction history information are transmitted from the first node device to the second node device, and the second node device verifies that the token transfer is a valid transfer of tokens issued by the true issuer (in other words, the validity of the token transfer). This makes it possible to verify the validity of the token transfer without extracting transaction information related to tokens from all transaction information recorded in the distributed ledger. Therefore, the load required to verify the validity of the token transfer can be reduced.

[0025] Furthermore, the second node device can verify the validity of token transfers in response to the receipt of new transaction information and transaction history information from the first node device. Therefore, the second node device can quickly verify the validity of token transfers. Next, the information processing system of the first embodiment will be described in more detail.

[0026] (composition) As shown in Figure 1, the information processing system 1 comprises a plurality of node devices 10-1, 10-2, ..., 10-N (in this example, N nodes). N represents an integer greater than or equal to 2. The number of node devices 10-n (where n is an integer from 1 to N) that constitute the information processing system 1 may change over time.

[0027] N node devices 10-1, 10-2, ..., 10-N are connected to each other via a communication line NW so that they can communicate with one another. The communication line NW may include a wireless communication transmission path. In this example, each node device 10-n has at least one wallet. However, at least one of the N node devices 10-1, 10-2, ..., 10-N may not have a wallet.

[0028] A wallet is a device that stores crypto assets. A wallet may also be referred to as a digital wallet. In this example, crypto assets include coins and tokens. In this example, the coin is Bitcoin. However, the coin may be a different cryptocurrency from Bitcoin (for example, BTC, Litecoin, Bitcoin Cash, Bitcoin SV, Dash, Deogecoin, or Zcash).

[0029] In this example, a token is a crypto asset distinct from a coin. For example, a token may be a different virtual currency from a coin. Furthermore, a token may be issued on an existing blockchain and used to digitally represent or manage specific rights, attributes, values, data, or functions. A token may also represent the right to use a specific service, the right to own a specific item, or the right to purchase a specific item.

[0030] For example, a token may be called a Layer 0 token, a Layer 1 token, or a Layer 2 token. Also, for example, a token may be called an NFT (Non-Fungible Token) or an FT (Fungible Token).

[0031] Information processing system 1 records transaction information in a distributed ledger composed of a blockchain by having N node devices 10-1, 10-2, ..., 10-N communicate in a peer-to-peer manner. Transaction information represents the transfer of tokens associated with coins between two wallets out of several wallets (in other words, a transaction). Transaction information may also simply be referred to as "transaction." The distributed ledger is stored in a distributed state across N node devices 10⁻¹, 10⁻², ..., 10⁻N.

[0032] In this example, information processing system 1 uses a blockchain that follows the UTXO (Unspent Transaction Output) method. Alternatively, information processing system 1 may use a blockchain that follows a token-based method, an account-based method (in other words, an account-based method), or a hybrid method combining the UTXO and account methods. Furthermore, information processing system 1 may use DLT (Distributed Ledger Technology). In this case, information processing system 1 may use, for example, a Directed Acyclic Graph.

[0033] Each node device 10-n is an information processing device or a computer. For example, the computer may be a server computer, a desktop computer, a laptop computer, a tablet computer, or a smartphone. Alternatively, the computer may be at least part of a payment terminal, a stationary game console, a portable game console, or a television receiver. Each node device 10-n may be composed of multiple devices that are connected to each other in a manner that enables communication.

[0034] As shown in Figure 2, each node device 10-n comprises a processing unit 11, a storage device 12, an input device 13, an output device 14, and a communication device 15, all connected to each other via a bus BU. The processing unit 11 controls the storage device 12, the input device 13, the output device 14, and the communication device 15 by executing a program stored in the storage device 12. As a result, each node device 10-n realizes the functions described later.

[0035] In this example, the processing unit 11 is a CPU (Central Processing Unit). However, the processing unit 11 may also include, in addition to or instead of a CPU, an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field-Programmable Gate Array), an ASIC (Application-Specific Integrated Circuit), or a TPU (Tensor Processing Unit).

[0036] In this example, the storage device 12 includes volatile memory and non-volatile memory. For example, the storage device 12 includes at least one of RAM (Random Access Memory), ROM (Read Only Memory), semiconductor memory, organic memory, HDD (Hard Disk Drive), and SSD (Solid State Drive).

[0037] Input device 13 receives information from outside node device 10-n. In this example, input device 13 is equipped with a keyboard and a mouse. Input device 13 may also be equipped with a microphone. Output device 14 outputs information to the outside of node device 10-n. In this example, output device 14 is equipped with a display. Output device 14 may also be equipped with a speaker. Furthermore, node device 10-n may be equipped with a touch panel display that constitutes both the input device 13 and the output device 14.

[0038] The communication device 15 communicates with devices outside of the node devices 10-n. In this example, the communication device 15 includes a card-type or onboard network adapter or network interface.

[0039] (function) As shown in Figure 3, the functions of each node device 10-n include a granting function unit 110, a receiving function unit 120, and a transaction history information storage unit 130. Furthermore, at least one function among the N node devices 10-1, 10-2, ..., 10-N does not necessarily have to include either the awarding function unit 110 or the receiving function unit 120.

[0040] The granting function unit 110 includes a token transfer condition request transmission unit 111, a token transfer condition information reception unit 112, a transaction information generation unit 113, a transaction information transmission unit 114, and a transfer result notification reception unit 115.

[0041] The receiving function unit 120 includes a token transfer condition request receiving unit 121, a token transfer condition information transmission unit 122, a transaction information receiving unit 123, an issuance hash value information acquisition unit 124, a rule information acquisition unit 125, a transaction information verification unit 126, a broadcast transmission unit 127, a confirmation processing unit 128, and a transfer result notification transmission unit 129.

[0042] As shown in Figure 4 below, we will explain each functional part of node device 10-n, focusing on the function related to token issuance of node device 10-i (where i represents an integer from 1 to N) that is issuing tokens (in other words, the source of the token transfer), and the function related to token receipt of node device 10-j (where j represents an integer from 1 to N that is different from i) that is receiving the tokens (in other words, the destination of the token transfer).

[0043] In this example, the awarding node device 10-i corresponds to the first node device, and the wallet possessed by the awarding node device 10-i corresponds to the first wallet. Also in this example, the receiving node device 10-j corresponds to the second node device, and the wallet possessed by the receiving node device 10-j corresponds to the second wallet.

[0044] The token transfer condition request transmission unit 111 of the awarding node device 10-i transmits the token transfer condition request to the receiving node device 10-j. A token transfer condition request is information that indicates a request for token transfer condition information, which represents the conditions for the transfer of tokens.

[0045] The token transfer condition request receiving unit 121 of the receiving node device 10-j receives a token transfer condition request from the awarding node device 10-i. When the token transfer condition information transmission unit 122 of the receiving node device 10-j receives a token transfer condition request from the token transfer condition request receiving unit 121, it transmits the token transfer condition information to the awarding node device 10-i, which is the source of the token transfer condition request.

[0046] For example, token transfer condition information represents the token transfer conditions, which are the requirements for the tokens to be transferred. In this example, the token transfer conditions include information that identifies the token rule set of the tokens to be transferred, information that identifies the type of tokens to be transferred, information that represents the amount of tokens to be transferred, and information that represents the period during which the token transfer will be accepted.

[0047] A token ruleset is a set of rules for issuing and managing tokens. The token ruleset is determined by the token issuer. For example, it might specify the token supply, the token issuer, the token issuance method, the token price, how the tokens can be used, how the tokens can be stored, or how the tokens can be transferred.

[0048] For example, the token rule set may be defined using a token protocol such as Ordinals, BRC-20, BSV-20, 1-sat Ordinals, Stas Token, Run on Bitcoin, Bitcoin Computer Token, Sensible, Elas Token, Simple Fabriik Protocol for Tokens (SFP), CRC-20, Simple Ledger Protocol (SLP), Color Coin, Counterparty, Omni, or Open Asset Protocol.

[0049] The token transfer condition information receiving unit 112 of the awarding node device 10-i receives token transfer condition information from the receiving node device 10-j, which is the destination of the token transfer condition request.

[0050] When the token transfer condition information is received by the token transfer condition information receiving unit 112, the transaction information generation unit 113 of the awarding node device 10-i generates new transaction information that satisfies the token transfer conditions represented by the received token transfer condition information.

[0051] The new transaction information represents the transfer of coins and tokens from the first wallet to the second wallet. In this example, the token transfer occurs along with the coin transfer.

[0052] In this example, transaction information represents the exchange (in other words, transfer) of coins and tokens. In this example, transaction information includes at least one input piece of information and at least one output piece of information.

[0053] The input information identifies the output information from which the coins being transferred originated (in other words, from the previous transfer), and includes information that proves the right to use those coins. In this example, the input information includes the previous transfer information, the output identification information, and the restriction removal information.

[0054] The previous transfer information included in the input information is information that identifies the previous transfer transaction information, which is transaction information representing the transfer immediately preceding the transfer represented by the transaction information containing the input information. In this example, the previous transfer information is the previous transfer hash value information generated by inputting the previous transfer transaction information into a hash function.

[0055] In this example, the hash function is SHA-256 (Secure Hash Algolithm 256-bit). However, other hash functions (e.g., SHA-3) may also be used.

[0056] In this example, the previous transfer hash value information is the hash value information generated by inputting the previous transfer transaction information into a hash function, and then inputting that hash value information into the hash function again (in other words, double hash value information). Alternatively, the previous transfer hash value information may also be the hash value information generated by inputting the previous transfer transaction information into a hash function (in other words, single hash value information).

[0057] The output identification information included in the input information is information that identifies the output information included in the previous transfer transaction information, which is identified by the previous transfer information included in the input information. The restriction removal information included in the input information is information that proves the right to use the source coin represented by the output information identified by that input information.

[0058] The output information includes the amount of coins being transferred, as well as information restricting the use of those coins so that only the wallet to which they are being transferred has the right to use them. In this example, the output information includes information on the amount of coins transferred and information on usage restrictions.

[0059] The transfer amount information included in the output data represents the amount of coins being transferred. The usage restriction information included in the output information is information that restricts the use of the coin so that only the wallet to which the coin is transferred can prove its right to use it.

[0060] Furthermore, transaction information includes token transfer information, which represents the transfer of tokens associated with the coin. For example, token transfer information may include information representing the amount of tokens to be transferred. However, token transfer information does not necessarily have to include information representing the amount of tokens to be transferred. In this case, the amount of tokens to be transferred may be determined based on the information representing the amount of coins to be transferred. For example, token transfer information may include information identifying the wallet to which the tokens are being transferred. If the token transfer information does not include information identifying the wallet to which the tokens are being transferred, the destination of the tokens may be the same as the destination of the coins.

[0061] In this example, token transfer information is included in at least one of the restriction removal information and the usage restriction information. Note that token transfer information may also be included in information other than the restriction removal information and the usage restriction information.

[0062] The transaction information transmission unit 114 of the awarding node device 10-i transmits the new transaction information generated by the transaction information generation unit 113 and the transaction history information stored in the transaction history information storage unit 130 to the receiving node device 10-j. In this example, the transaction information transmission unit 114 corresponds to the transmission unit.

[0063] Transaction history information transmitted along with new transaction information representing the transfer of coins and tokens includes a set of transaction information (in other words, multiple transaction information) corresponding to the history of the transfer of the token from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history.

[0064] In this example, in the transaction history information, the transaction information group corresponding to the history of token transfers is arranged in the order of the transfers in that history. However, in the transaction history information, the transaction information group corresponding to the history of token transfers may also be arranged in the reverse order of the transfers in that history. Furthermore, in the transaction history information, each of the multiple transaction information items corresponding to the history of token transfers may be associated with information that identifies the order of the transfers in that history.

[0065] The transaction information receiving unit 123 of the receiving node device 10-j receives new transaction information and transaction history information from the awarding node device 10-i. In this example, the transaction information receiving unit 123 corresponds to the receiving unit.

[0066] The issued hash value information acquisition unit 124 of the receiving node device 10-j acquires the issued hash value information. In this example, the issued hash value information acquisition unit 124 corresponds to the acquisition unit. The issuance hash value information is generated by inputting transaction information representing the token issuance into a hash function. In this example, the issuance hash value information is a double hash value. However, the issuance hash value information may also be a single hash value.

[0067] Transaction information representing the issuance of a token may also be represented as token genesis. In this example, the transaction information representing the issuance of a token is generated by the token issuer. In this example, the issuance hash value information acquisition unit 124 obtains the issuance hash value information from the token issuer. For example, the issuance hash value information acquisition unit 124 may obtain the issuance hash value information by receiving the issuance hash value information from an information processing device managed by the token issuer.

[0068] The rule information acquisition unit 125 of the receiving node device 10-j acquires rule information. In this example, the rule information acquisition unit 125 corresponds to the acquisition unit. Rule information represents the rules that the token transfer information included in the transaction information follows. In this example, the rule information represents the token rule set.

[0069] Rule information is generated by the token issuer. In this example, the rule information acquisition unit 125 acquires rule information from the token issuer. For example, the rule information acquisition unit 125 may acquire rule information by receiving it from an information processing device managed by the token issuer.

[0070] The transaction information verification unit 126 of the receiving node device 10-j performs token transfer verification based on the new transaction information and transaction history information received by the transaction information receiving unit 123, verifying that the transfer of tokens from the first wallet to the second wallet is a valid transfer of tokens issued by the true issuer. In this example, the transaction information verification unit 126 corresponds to the verification unit.

[0071] In this example, token transfer verification includes record verification, sequential verification, issuance verification, and rule verification. Record verification verifies that the transaction information representing the transfer immediately preceding the transfer represented by the new transaction information, which is included in the transaction history information, is recorded in the distributed ledger.

[0072] Sequential verification verifies that for each pair of transaction information consisting of two transaction information items representing two consecutive transfers, which are comprised of new transaction information and a group of transaction information items included in the transaction history information, the hash value information generated by inputting the transaction information representing the preceding transfer into a hash function matches the hash value information of the previous transfer included in the transaction information representing the subsequent transfer (in this example, the previous transfer information).

[0073] Issuance verification involves verifying that the hash value information generated by inputting the transaction information representing the issuance of a token from the transaction information group included in the transaction history information into a hash function matches the issuance hash value information obtained by the issuance hash value information acquisition unit 124.

[0074] Rule verification verifies that for each of the multiple transaction information sets, which consist of new transaction information and transaction information sets included in transaction history information, the token transfer information included in the transaction information conforms to the rules (in this example, the token rule set) represented by the rule information acquisition unit 125.

[0075] If the token transfer verification by the transaction information verification unit 126 is successful, the broadcast transmission unit 127 of the receiving node device 10-j broadcasts the new transaction information received by the transaction information receiving unit 123 to the group of node devices other than the receiving node device 10-j among the N node devices 10-1, 10-2, ..., 10-N.

[0076] On the other hand, if the token transfer verification by the transaction information verification unit 126 fails, the broadcast transmission unit 127 does not transmit the new transaction information received by the transaction information receiving unit 123. In this example, the broadcast transmission unit 127 corresponds to the transmission unit.

[0077] When new transaction information is transmitted by the broadcast transmission unit 127, the confirmation processing unit 128 of the receiving node device 10-j sends a confirmation request to the group of node devices other than the receiving node device 10-j among the N node devices 10-1, 10-2, ..., 10-N. The confirmation request includes information that identifies the new transaction information and information that indicates a request for a confirmation response indicating whether or not the new transaction information has been recorded in the distributed ledger.

[0078] In this example, the node cluster verifies that the transfer of coins represented by the new transaction information is valid and records the new transaction information in the distributed ledger. In this example, the distributed ledger has multiple blocks, each containing information on multiple transactions. The process performed by the node cluster to record the new transaction information in the distributed ledger includes a process called mining.

[0079] The confirmation processing unit 128 receives confirmation responses sent from the node device group in response to the transmission of a confirmation request. The confirmation response to a confirmation request is information indicating whether or not the new transaction information identified by the confirmation request has been recorded in the distributed ledger.

[0080] The transfer result notification transmission unit 129 of the receiving node device 10-j transmits a transfer result notification to the awarding node device 10-i. The transfer result notification indicates the result of the transfer of coins and tokens. In this example, the transfer result notification is either a transfer approval notification or a transfer failure notification. A transfer approval notification indicates that the transfer of coins and tokens has been approved. A transfer failure notification indicates that the transfer of coins and tokens has not been approved (in other words, the transfer failed).

[0081] If the token transfer verification by the transaction information verification unit 126 is successful and the verification processing unit 128 receives a confirmation response indicating that the new transaction information has been recorded in the distributed ledger, the transfer approval notification unit 129 sends a transfer result notification to the awarding node device 10-i.

[0082] On the other hand, if the token transfer verification by the transaction information verification unit 126 fails, the transfer result notification transmission unit 129 sends a transfer failure notification as a transfer result notification to the awarding node device 10-i.

[0083] The transfer result notification receiving unit 115 of the awarding node device 10-i receives a transfer result notification from the receiving node device 10-j. If the transfer result notification is a transfer approval notification, the transfer result notification receiving unit 115 outputs transfer approval information. The transfer approval information is information indicating that the transfer of coins and tokens has been approved.

[0084] On the other hand, the transfer result notification receiving unit 115 outputs transfer failure information if the transfer result notification is a transfer failure notification. Transfer failure information indicates that the transfer of coins and tokens was not approved (in other words, the transfer failed).

[0085] When the transaction history information storage unit 130 of the receiving node device 10-j receives confirmation from the confirmation processing unit 128 that the token transfer verification by the transaction information verification unit 126 has been successful and that new transaction information has been recorded in the distributed ledger, it updates the transaction history information by adding the new transaction information to the transaction history information received by the transaction information receiving unit 123 along with the new transaction information, and stores the updated transaction history information.

[0086] (operation) Next, the operation of the information processing system 1 will be explained with reference to Figures 5 through 12. Figure 5 is a sequence diagram showing an example of the operation of the information processing system 1. Figure 6 is a flowchart showing an example of the awarding process performed by the awarding node device 10-i. Figure 7 is a flowchart showing an example of the receiving process performed by the receiving node device 10-j.

[0087] Figure 8 is a flowchart showing an example of token transfer verification performed by the receiving node device 10-j. Figure 9 is a flowchart showing an example of record verification performed by the receiving node device 10-j. Figure 10 is a flowchart showing an example of sequential verification performed by the receiving node device 10-j. Figure 11 is a flowchart showing an example of issuance verification performed by the receiving node device 10-j. Figure 12 is a flowchart showing an example of rule verification performed by the receiving node device 10-j.

[0088] In this example, the awarding node device 10-i performs the awarding process shown in Figure 6 in order to award coins and tokens. First, the awarding node device 10-i sends a token transfer condition request to the receiving node device 10-j (step S101 in Figure 5 and step S201 in Figure 6). Next, the awarding node device 10-i waits until it receives token transfer condition information from the receiving node device 10-j (the determination of "No" is repeated in step S202 in Figure 6).

[0089] In this example, the receiving node device 10-j executes the receiving process shown in Figure 7 in order to receive coins and tokens. The receiving node device 10-j waits until it receives a token transfer condition request (repeatedly determining "No" in step S301 of Figure 7).

[0090] Subsequently, the receiving node device 10-j receives a token transfer condition request from the issuing node device 10-i (step S101 in Figure 5). As a result, the receiving node device 10-j determines "Yes" in step S301 in Figure 7 and sends token transfer condition information to the issuing node device 10-i (steps S102 in Figure 5 and S302 in Figure 7). Next, the receiving node device 10-j waits until it receives new transaction information and transaction history information from the issuing node device 10-i (repeated determination of "No" in step S303 in Figure 7).

[0091] As a result, the awarding node device 10-i receives token transfer condition information from the receiving node device 10-j (step S102 in Figure 5). Therefore, the awarding node device 10-i determines "Yes" in step S202 in Figure 6 and generates new transaction information (steps S103 in Figure 5 and S203 in Figure 6).

[0092] Next, the awarding node device 10-i sends the newly generated transaction information and the transaction history information stored in the transaction history information storage unit 130 to the receiving node device 10-j (step S104 in Figure 5 and step S204 in Figure 6). Then, the awarding node device 10-i waits until it receives a transfer result notification from the receiving node device 10-j (the determination of "No" is repeated in step S205 in Figure 6).

[0093] As a result, the receiving node device 10-j receives new transaction information and transaction history information from the issuing node device 10-i (step S104 in Figure 5). Therefore, the receiving node device 10-j determines "Yes" in step S303 in Figure 7 and performs token transfer verification (step S105 in Figure 5 and step S304 in Figure 7).

[0094] The receiving node device 10-j performs the process shown in Figure 8 in order to perform token transfer verification. In the process shown in Figure 8, first, the receiving node device 10-j performs record verification (step S401 in Figure 8). To perform record verification, the receiving node device 10-j executes the process shown in Figure 9.

[0095] In the process shown in Figure 9, first, the receiving node device 10-j determines whether the Mth transaction information is recorded in the distributed ledger (in other words, whether it has been recorded) (step S501 in Figure 9). M represents the transaction number, which is the number of transaction information entries included in the transaction history information. In this example, the mth transaction information is the transaction information that is the mth in order from the beginning in the history of token transfers. m represents an integer from 1 to M+1. Therefore, in this example, the first transaction information is the transaction information representing the issuance of a token. Also, in this example, the M+1th transaction information is new transaction information.

[0096] If the receiving node device 10-j maintains a distributed ledger, it makes the above determination based on the distributed ledger it maintains. If the receiving node device 10-j does not maintain a distributed ledger, it makes the above determination by communicating with the group of node devices.

[0097] If the receiving node device 10-j has recorded the Mth transaction information in the distributed ledger, it determines "Yes" in step S501 of Figure 9, sets the record verification success information to true (step S502 of Figure 9), and terminates the process in Figure 9. The record verification success information indicates whether or not the record verification was successful.

[0098] Furthermore, if the Mth transaction information is not recorded in the distributed ledger, the receiving node device 10-j determines "No" in step S501 of Figure 9, sets the record verification success information to a false value (step S503 of Figure 9), and terminates the process shown in Figure 9.

[0099] Next, the receiving node device 10-j determines whether the record verification success information is set to a true value (step S402 in Figure 8). If the record verification success information is set to true, the receiving node device 10-j determines "Yes" in step S402 of Figure 8 and performs continuous verification (step S403 of Figure 8). In order to perform continuous verification, the receiving node device 10-j executes the process shown in Figure 10.

[0100] In the process shown in Figure 10, first, the receiving node device 10-j sets the counter information p to 1 (step S601 in Figure 10). The counter information p represents an integer. Next, the receiving node device 10-j determines whether the counter information p is less than M+1, which is the number of transactions M plus 1 (step S602 in Figure 10).

[0101] At this point, the counter information p is less than M+1. Therefore, the receiving node device 10-j determines "Yes" in step S602 of Figure 10 and generates hash value information (double hash value information in this example) by inputting the p-th transaction information into the hash function (step S603 of Figure 10).

[0102] Next, the receiving node device 10-j determines whether the hash value information generated in step S603 of Figure 10 matches the previous transfer hash value information (in this example, the previous transfer information) contained in the p+1th transaction information (step S604 of Figure 10).

[0103] If the generated hash value information matches the previously transferred hash value information contained in the p+1th transaction information, the receiving node device 10-j determines "Yes" in step S604 of Figure 10 and sets the counter information p to p+1 (in other words, increases the counter information p by 1) (step S605 of Figure 10). Then, the receiving node device 10-j returns to step S602 of Figure 10 and repeatedly executes the processes from step S602 to step S605.

[0104] Subsequently, if the receiving node device 10-j proceeds to step S602 in Figure 10 while the counter information p is equal to M+1, the receiving node device 10-j determines "No", sets the continuous verification success information to true (step S607 in Figure 10), and terminates the process in Figure 10. The continuous verification success information indicates whether or not the continuous verification was successful.

[0105] Furthermore, if the generated hash value information in step S604 of Figure 10 does not match the previously transferred hash value information contained in the p+1th transaction information, the receiving node device 10-j determines "No", sets the success of the continuous verification information to a false value (step S606 of Figure 10), and terminates the process in Figure 10.

[0106] Next, the receiving node device 10-j determines whether the continuous verification success information is set to a true value (step S404 in Figure 8). If the continuous verification success information is set to true, the receiving node device 10-j determines "Yes" in step S404 of Figure 8 and performs issuance verification (step S405 of Figure 8). In order to perform issuance verification, the receiving node device 10-j executes the process shown in Figure 11.

[0107] In the process shown in Figure 11, first, the receiving node device 10-j generates hash value information (in this example, double hash value information) by inputting the first transaction information into a hash function (step S701 in Figure 11).

[0108] Next, the receiving node device 10-j determines whether the hash value information generated in step S701 of Figure 11 matches the previously acquired issued hash value information (step S702 of Figure 11).

[0109] If the receiving node device 10-j finds that the generated hash value information matches the previously obtained issuance hash value information, it determines "Yes" in step S702 of Figure 11, sets the issuance verification success information to true (step S703 of Figure 11), and terminates the process in Figure 11. The issuance verification success information indicates whether or not the issuance verification was successful.

[0110] Furthermore, if the generated hash value information does not match the previously obtained issued hash value information, the receiving node device 10-j determines "No" in step S702 of Figure 11, sets the successful issuance verification information to a false value (step S704 of Figure 11), and terminates the process shown in Figure 11.

[0111] Next, the receiving node device 10-j determines whether the issuance verification success information is set to a true value (step S406 in Figure 8). If the issuance verification success information is set to true, the receiving node device 10-j determines "Yes" in step S406 of Figure 8 and performs rule verification (step S407 of Figure 8). In order to perform rule verification, the receiving node device 10-j executes the process shown in Figure 12.

[0112] In the process shown in Figure 12, first, the receiving node device 10-j sets the counter information p to 1 (step S801 in Figure 12). Next, the receiving node device 10-j determines whether the counter information p is less than the value M+2, which is the number of transactions M plus 2 (step S802 in Figure 12).

[0113] At this point, the counter information p is less than M+2. Therefore, the receiving node device 10-j determines "Yes" in step S802 in Figure 12 and determines whether the token transfer information contained in the p-th transaction information conforms to the rule (in this example, the token rule set) represented by the previously acquired rule information (step S803 in Figure 12).

[0114] If the token transfer information contained in the p-th transaction information conforms to the rule, the receiving node device 10-j determines "Yes" in step S803 of Figure 12 and sets the counter information p to p+1 (in other words, increases the counter information p by 1) (step S804 of Figure 12). Then, the receiving node device 10-j returns to step S802 of Figure 12 and repeatedly executes the processes from step S802 to step S804.

[0115] Subsequently, if the receiving node device 10-j proceeds to step S802 in Figure 12 while the counter information p is equal to M+2, the receiving node device 10-j determines "No", sets the rule verification success information to true (step S806 in Figure 12), and terminates the process in Figure 12. The rule verification success information indicates whether or not the rule verification was successful.

[0116] Furthermore, in step S803 of Figure 12, if the token transfer information included in the p-th transaction information does not conform to the rule, the receiving node device 10-j determines "No", sets the rule verification success information to a false value (step S805 of Figure 12), and terminates the process in Figure 12.

[0117] Next, the receiving node device 10-j determines whether the rule verification success information is set to true (step S408 in Figure 8). If the rule verification success information is set to true, the receiving node device 10-j determines "Yes" in step S408 of Figure 8, sets the token transfer verification success information to true (step S409 of Figure 8), and terminates the process in Figure 8. The token transfer verification success information indicates whether or not the token transfer verification was successful.

[0118] Furthermore, if the record verification success information is set to a false value in step S402 of Figure 8, if the continuous verification success information is set to a false value in step S404 of Figure 8, if the issuance verification success information is set to a false value in step S406 of Figure 8, or if the rule verification success information is set to a false value in step S408 of Figure 8, the receiving node device 10-j determines "No", sets the token transfer verification success information to a false value (step S410 of Figure 8), and terminates the process in Figure 8.

[0119] Next, the receiving node device 10-j proceeds to step S305 in Figure 7, where it determines whether the token transfer verification success information is set to true (step S305 in Figure 7). If the token transfer verification success information is set to true, the receiving node device 10-j determines "Yes" and broadcasts the new transaction information received in step S303 of Figure 7 to the node device group (step S106 in Figure 5 and step S306 in Figure 7).

[0120] Next, the receiving node device 10-j sends a confirmation request to the node device group (step S107 in Figure 5 and step S307 in Figure 7). Then, the receiving node device 10-j waits until it receives a confirmation response from the node device group (the determination of "No" is repeated in step S308 in Figure 7).

[0121] On the other hand, when the node group receives a confirmation request from the receiving node device 10-j, it sends a confirmation response to the receiving node device 10-j in response to the receipt of the confirmation request (step S108 in Figure 5). As a result, the receiving node device 10-j receives a confirmation response from the node group (step S108 in Figure 5). Therefore, the receiving node device 10-j determines "Yes" in step S308 in Figure 7 and determines whether the received confirmation response indicates that new transaction information has been recorded in the distributed ledger (step S309 in Figure 7).

[0122] At this point, no new transaction information has been recorded in the distributed ledger. Therefore, the receiving node device 10-j determines "No" in step S309 in Figure 7, returns to step S307 in Figure 7, and repeatedly executes the processes from step S307 to step S309.

[0123] Subsequently, the node devices verify that the coin transfer represented by the new transaction information is a valid transfer of coins issued by the true issuer, and record the new transaction information in the distributed ledger (step S109 in Figure 5).

[0124] Subsequently, the receiving node device 10-j sends a confirmation request to the node device group (step S110 in Figure 5 and step S307 in Figure 7). In response to receiving the confirmation request, the node device group sends a confirmation reply to the receiving node device 10-j (step S111 in Figure 5). As a result, the receiving node device 10-j receives the confirmation reply from the node device group (step S111 in Figure 5).

[0125] At this point, the new transaction information is recorded in the distributed ledger. Therefore, the receiving node device 10-j determines "Yes" in step S309 in Figure 7 and sends a transfer approval notice to the issuing node device 10-i (step S112 in Figure 5 and step S310 in Figure 7).

[0126] As a result, the awarding node device 10-i receives a transfer result notification, which is a transfer approval notification, from the receiving node device 10-j (step S112 in Figure 5). Therefore, the awarding node device 10-i determines "Yes" in step S205 in Figure 6 and determines whether the received transfer result notification represents approval of the transfer (in other words, it is a transfer approval notification) (step S206 in Figure 6).

[0127] At this point, the received transfer result notification indicates approval of the transfer. Therefore, the awarding node device 10-i determines "Yes" in step S206 of Figure 6, outputs the transfer approval information (step S207 of Figure 6), and terminates the process in Figure 6.

[0128] Meanwhile, the receiving node device 10-j sends a transfer approval notice to the awarding node device 10-i (step S112 in Figure 5 and step S310 in Figure 7). Then, in step S303 in Figure 7, it updates the transaction history information by adding the new transaction information received in step S303 in Figure 7 to the transaction history information received in step S303 in Figure 7, and stores the updated transaction history information (step S113 in Figure 5 and step S311 in Figure 7).

[0129] Next, the receiving node device 10-j returns to step S301 in Figure 7 and repeatedly executes the processes from step S301 to step S312.

[0130] Furthermore, if the token transfer verification success information is set to a false value in step S305 of Figure 7, the receiving node device 10-j determines "No", sends a transfer failure notification to the issuing node device 10-i (step S312 of Figure 7), and returns to step S301 of Figure 7.

[0131] In this case, if the awarding node device 10-i proceeds to step S206 in Figure 6, it determines "No", outputs transfer failure information (step S208 in Figure 6), and terminates the process in Figure 6. Note that the order in which record verification, serial verification, issuance verification, and rule verification are performed may differ from the order illustrated in Figure 8.

[0132] As described above, the information processing system 1 of the first embodiment records transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, by having multiple node devices 10-1, 10-2, ..., 10-N, each having multiple wallets, communicate in a peer-to-peer manner.

[0133] The first node device having the first wallet (in this example, the awarding node device 10-i) comprises a generation unit (in this example, the transaction information generation unit 113) and a transmission unit (in this example, the transaction information transmission unit 114).

[0134] The generation unit generates new transaction information, which is transaction information representing the transfer of tokens from the first wallet to the second wallet. The transmitting unit sends the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the token's transfers from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet (in this example, the receiving node device 10-j).

[0135] The second node device comprises a receiving unit (in this example, a transaction information receiving unit 123) and a verification unit (in this example, a transaction information verification unit 126). The receiving unit receives new transaction information and transaction history information. The verification unit performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer.

[0136] According to this system, new transaction information and transaction history information are transmitted from the first node device to the second node device, and the second node device verifies that the token transfer is a valid transfer of tokens issued by the true issuer (in other words, the validity of the token transfer). This makes it possible to verify the validity of the token transfer without extracting transaction information related to tokens from all transaction information recorded in the distributed ledger. Therefore, the load required to verify the validity of the token transfer can be reduced.

[0137] Furthermore, the second node device can verify the validity of token transfers in response to the receipt of new transaction information and transaction history information from the first node device. Therefore, the second node device can quickly verify the validity of token transfers.

[0138] Furthermore, in the information processing system 1 of the first embodiment, the transaction information includes the most recent transfer hash value information, which is generated by inputting the transaction information representing the transfer immediately preceding the transfer represented by the transaction information into a hash function. Furthermore, the verification unit performs token transfer verification by performing a sequential verification on each of the transaction information pairs, which consist of two transaction information items representing two consecutive transfers from among the multiple transaction information items, which consist of new transaction information and a group of transaction information items included in the transaction history information. This verification verifies that the hash value information generated by inputting the transaction information representing the preceding transfer into a hash function matches the hash value information of the previous transfer included in the transaction information representing the subsequent transfer.

[0139] According to this, it is possible to verify with high accuracy that multiple transfers represented by multiple transaction information, each consisting of new transaction information and transaction information included in the transaction history information, are consecutive. As a result, the validity of the token transfer to the second wallet can be verified with high accuracy.

[0140] Furthermore, in the information processing system 1 of the first embodiment, the second node device includes an acquisition unit (in this example, an issuance hash value information acquisition unit 124) that acquires issuance hash value information generated by inputting transaction information representing the issuance of a token into a hash function. Furthermore, the verification unit performs token transfer verification by executing issuance verification, which verifies that the hash value information generated by inputting transaction information, which is included in the transaction history information and represents the issuance of a token, into a hash function matches the obtained issuance hash value information.

[0141] This allows for highly accurate verification that the token was issued by the true issuer. As a result, the validity of the token transfer to the second wallet can be verified with high accuracy.

[0142] Furthermore, in the information processing system 1 of the first embodiment, transaction information includes token transfer information representing the transfer of tokens. Furthermore, the second node device includes an acquisition unit (in this example, a rule information acquisition unit 125) that acquires rule information representing the rules that the token transfer information included in the transaction information follows. Furthermore, the verification unit performs token transfer verification by executing rule verification on each of the multiple transaction information sets, which consist of new transaction information and a group of transaction information sets included in the transaction history information, to verify that the token transfer information included in the transaction information conforms to the rules represented by the acquired rule information.

[0143] According to this method, it is possible to verify with high accuracy that the token transfer information contained in each of the multiple transaction information sets, which consist of new transaction information and transaction information sets included in transaction history information, conforms to the rules. As a result, the validity of the token transfer to the second wallet can be verified with high accuracy.

[0144] Furthermore, in the information processing system 1 of the first embodiment, the verification unit performs token transfer verification by performing record verification, which verifies that transaction information included in the transaction history information and representing the transfer immediately preceding the transfer represented by the new transaction information is recorded in the distributed ledger.

[0145] According to this, the transaction information representing the token transfer immediately preceding the transfer of tokens from the first wallet to the second wallet can be verified with high accuracy as a valid transfer of coins issued by the true issuer. As a result, the validity of the token transfer to the second wallet can be verified with high accuracy.

[0146] Furthermore, in the information processing system 1 of the first embodiment, the second node device includes a transmission unit (in this example, a broadcast transmission unit 127) that transmits new transaction information by broadcast if token transfer verification is successful, and does not transmit new transaction information if token transfer verification fails.

[0147] According to this, it is possible to prevent transaction information where token transfer verification failed from being recorded in the distributed ledger.

[0148] <First modified example of the first embodiment> Next, the information processing system of the first modified example of the first embodiment will be described. The information processing system of the first modified example of the first embodiment differs from the information processing system of the first embodiment in that it omits the execution of the same verification on transaction information for which issuance verification or rule verification has already been successful. The following will focus on the differences. In the description of the first modified example of the first embodiment, parts that are given the same reference numerals as those used in the first embodiment are the same or substantially the same.

[0149] (function) As shown in Figure 13, the function of the node device 10A-n of the first modified example of the first embodiment is the function of the node device 10-n of the first embodiment in which the receiving function unit 120 is replaced by the receiving function unit 120A.

[0150] The receiving function unit 120A includes a verified transaction identification information storage unit 141A in addition to the functions of the receiving function unit 120 of the first embodiment, and the transaction information verification unit 126 in the receiving function unit 120 of the first embodiment is replaced by a transaction information verification unit 126A.

[0151] The verified transaction identification information storage unit 141A stores verified transaction identification information that identifies the transaction information if the issuance verification of the transaction information is successful. In this example, the verified transaction identification information that identifies the transaction information is hash value information (double hash value information in this example) generated by inputting the transaction information into a hash function.

[0152] Furthermore, the verified transaction identification information storage unit 141A stores verified transaction identification information that identifies the transaction information if rule verification of the transaction information is successful.

[0153] The transaction information verification unit 126A has the same functions as the transaction information verification unit 126 of the first embodiment. Furthermore, the transaction information verification unit 126A omits the execution of issuance verification for transaction information identified by verified transaction identification information stored in the verified transaction identification information storage unit 141A.

[0154] Furthermore, the transaction information verification unit 126A omits the execution of rule verification for transaction information identified by the verified transaction identification information stored in the verified transaction identification information storage unit 141A.

[0155] Furthermore, the transaction information verification unit 126A may omit either the execution of issuance verification or the execution of rule verification.

[0156] (operation) In the first modified example of the first embodiment, the receiving node device 10A-j performs the process shown in Figure 14 instead of the process shown in Figure 7. The process in Figure 14 is the same as the process in Figure 7, but with step S313A added immediately after step S311.

[0157] In the process shown in Figure 14, after the receiving node device 10A-j executes the process in step S311 of Figure 14, it generates hash value information (in this example, double hash value information) for each of the multiple transaction information items, which consist of the new transaction information received in step S303 of Figure 14 and the transaction information group included in the transaction history information received in step S303 of Figure 14, by inputting the transaction information into a hash function, and stores the generated hash value information as verified transaction identification information (step S313A of Figure 14). Subsequently, the receiving node device 10A-j returns to step S301 in Figure 14.

[0158] Note that the processing in step S313A in Figure 14 may be performed between steps S306 and S311 in Figure 14. Also, even if token transfer verification fails, the receiving node device 10A-j may store verified transaction identification information for the transaction information if issuance verification or rule verification for the transaction information is successful.

[0159] Furthermore, the receiving node device 10A-j of the first modified example of the first embodiment performs the process shown in Figure 15 instead of the process shown in Figure 11. The process in Figure 15 is the same as the process in Figure 11, but with step S705A added immediately before step S701.

[0160] In the process shown in Figure 15, the receiving node device 10A-j first determines whether the previous transfer hash value information (in this example, the previous transfer information) contained in the second transaction information matches one of the stored verified transaction identification information (step S705A in Figure 15).

[0161] If the immediately preceding transfer hash value information matches one of the stored verified transaction identification information, the receiving node device 10A-j determines "Yes" in step S705A of Figure 15 and proceeds to step S703 of Figure 15. As a result, the execution of steps S701 to S702 of Figure 15 is omitted.

[0162] On the other hand, if the immediately preceding transfer hash value information does not match any of the stored verified transaction identification information, the receiving node device 10A-j determines "No" in step S705A of Figure 15 and proceeds to step S701 of Figure 15.

[0163] Furthermore, the receiving node device 10A-j of the first modified example of the first embodiment performs the process shown in Figure 16 instead of the process shown in Figure 12. The process in Figure 16 is the same as the process in Figure 12, but with steps S807A to S808A added immediately after the "Yes" determination in step S802.

[0164] In the process shown in Figure 16, if the receiving node device 10A-j determines "Yes" in step S802 of Figure 16, it determines whether the counter information p is less than the transaction number M plus 1 (step S807A of Figure 16).

[0165] If the counter information p is less than M+1, the receiving node device 10A-j determines "Yes" in step S807A of Figure 16, and determines whether the previous transfer hash value information (in this example, the previous transfer information) contained in the p-th transaction information matches one of the stored verified transaction identification information (step S808A of Figure 16).

[0166] If the immediately preceding transfer hash value information matches one of the stored verified transaction identification information, the receiving node device 10A-j determines "Yes" in step S808A of Figure 16 and proceeds to step S804 of Figure 16. As a result, the execution of the process in step S803 of Figure 16 is omitted.

[0167] On the other hand, if the immediately preceding transfer hash value information does not match any of the stored verified transaction identification information, the receiving node device 10A-j determines "No" in step S808A in Figure 16 and proceeds to step S803 in Figure 16.

[0168] If the counter information p is equal to M+1, the receiving node device 10A-j determines "No" in step S807A of Figure 16 and proceeds to step S803 of Figure 16.

[0169] As described above, the information processing system 1 of the first modified example of the first embodiment provides the same functions and effects as the information processing system 1 of the first embodiment. Furthermore, in the information processing system 1 of the first modified example of the first embodiment, the second node device (in this example, the receiving node device 10A-j) includes a verified transaction identification information storage unit 141A that stores verified transaction identification information that identifies the transaction information when the issuance verification of the transaction information is successful. Furthermore, the verification unit (in this example, the transaction information verification unit 126A) omits the execution of issuance verification for the transaction information identified by the stored verified transaction identification information.

[0170] According to this, if the second node device receives transaction history information that includes transaction information for which issuance verification has already been successfully completed, the execution of issuance verification for that transaction information is omitted. This reduces the load required to verify the validity of token transfers. Furthermore, it enables rapid verification of the validity of token transfers.

[0171] Furthermore, in the information processing system 1 of the first modified example of the first embodiment, the second node device includes a verified transaction identification information storage unit 141A that stores verified transaction identification information that identifies the transaction information when rule verification of the transaction information is successful. Furthermore, the verification unit omits the execution of rule verification on the transaction information identified by the stored verified transaction identification information.

[0172] According to this, if the second node device receives transaction history information that includes transaction information for which rule verification has already been successfully performed, the execution of rule verification for that transaction information is omitted. This reduces the load required to verify the validity of token transfers. Furthermore, it enables rapid verification of the validity of token transfers.

[0173] <Second variation of the first embodiment> Next, the information processing system of the second modified example of the first embodiment will be described. The information processing system of the second modified example of the first embodiment differs from the information processing system of the first embodiment in that it omits the execution of the part of token transfer verification that corresponds to transaction history information for which token transfer verification has already been successful. The following will focus on the differences. In the description of the second modified example of the first embodiment, reference numerals used in the first embodiment are the same or substantially the same.

[0174] (function) As shown in Figure 17, the function of the node device 10B-n in the second modified example of the first embodiment is the function of the node device 10-n in the first embodiment in which the receiving function unit 120 is replaced by the receiving function unit 120B.

[0175] The receiving function unit 120B includes a verified transaction history identification information storage unit 142B in addition to the functions of the receiving function unit 120 of the first embodiment, and the transaction information verification unit 126 in the receiving function unit 120 of the first embodiment is replaced by a transaction information verification unit 126B.

[0176] In this example, the transaction information includes transfer history hash value information. The transfer history hash value information included in the transaction information representing the transfer of a token is generated by inputting the transaction history information, which includes the transaction information corresponding to the history of the token's transfers from the time the token was issued up to the transfer immediately preceding the transfer represented by the transaction information, in association with the order of transfers in that history, into a hash function.

[0177] In this example, the transfer history hash value information is a hash value information generated by inputting the transaction history information into a hash function, and then inputting that hash value information into the hash function again (in other words, double hash value information). Alternatively, the transfer history hash value information may also be a hash value information generated by inputting the transaction history information into a hash function (in other words, single hash value information).

[0178] The verified transaction history identification information storage unit 142B stores verified transaction history identification information for new transaction information and transaction history information received by the transaction information receiving unit 123 if the token transfer verification by the transaction information verification unit 126B is successful.

[0179] The verified transaction history identification information for new transaction information and transaction history information representing token transfers is information that identifies transaction history information that includes a group of transaction information corresponding to the history of token transfers from the time the token was issued up to the transfer represented by the new transaction information, in association with the order of transfers in that history.

[0180] In this example, the verified transaction history identifier for new transaction information and transaction history information representing a token transfer is hash value information (in this example, double hash value information) (in other words, transfer history hash value information) generated by inputting transaction history information, which includes a group of transaction information corresponding to the history of the token's transfer from the time the token was issued up to the transfer represented by the new transaction information, in association with the order of transfers in that history, into a hash function.

[0181] The transaction information verification unit 126B has the same functions as the transaction information verification unit 126 of the first embodiment. Furthermore, the transaction information verification unit 126B omits the execution of the portion of the token transfer verification for the new transaction information and transaction history information received by the transaction information receiving unit 123 that corresponds to the transaction history information identified by the verified transaction history identification information stored in the verified transaction history identification information storage unit 142B.

[0182] In this example, the transaction information verification unit 126B omits the execution of the portion of the token transfer verification for the new transaction information and transaction history information received by the transaction information receiving unit 123 that corresponds to the history of the token's transfer from the time the token was issued up to the transfer immediately preceding the transfer represented by the transaction information, which includes transfer history hash value information that matches the verified transaction history identification information stored in the verified transaction history identification information storage unit 142B.

[0183] (operation) In the second modified example of the first embodiment, the receiving node device 10B-j performs the process shown in Figure 18 instead of the process shown in Figure 7. The process shown in Figure 18 is the same as the process in Figure 7, but with step S313B added immediately after step S311.

[0184] In the process shown in Figure 18, the receiving node device 10B-j executes the process in step S311 of Figure 18, then inputs the transaction history information stored in step S311 of Figure 18 into a hash function to generate hash value information (double hash value information in this example), and stores the generated hash value information as verified transaction history identification information (step S313B of Figure 18). Subsequently, the receiving node device 10B-j returns to step S301 in Figure 18.

[0185] Note that the process in step S313B in Figure 18 may be performed between steps S306 and S311 in Figure 18.

[0186] Furthermore, the receiving node device 10B-j of the second modified example of the first embodiment performs the process shown in Figure 19 instead of the process shown in Figure 8. The process shown in Figure 19 is the same as the process in Figure 8, but with step S411B added immediately before step S401.

[0187] In the process shown in Figure 19, first, the receiving node device 10B-j performs a verification determination (step S411B in Figure 19). In order to perform the verification determination, the receiving node device 10B-j executes the process shown in Figure 20.

[0188] In the process shown in Figure 20, first, the receiving node device 10B-j sets the verified specific information q to -1 (step S901B in Figure 20). In this example, the verified specific information q represents an integer. Next, the receiving node device 10B-j sets the counter information p to M+1, which is the transaction number M plus 1 (step S902B in Figure 20).

[0189] Next, the receiving node device 10B-j determines whether the counter information p is greater than 0 (step S903B in Figure 20). At this point, the counter information p is greater than 0. Therefore, the receiving node device 10B-j determines "Yes" in step S903B of Figure 20 and determines whether the transfer history hash value information contained in the p-th transaction information matches one of the stored verified transaction history identification information (step S904B of Figure 20).

[0190] If the transfer history hash value information matches any one of the stored verified transaction history identification information, the receiving node device 10B-j determines "Yes" in step S904B of Figure 20, sets the verified identification information q to p-1 (step S905B of Figure 20), and terminates the process in Figure 20.

[0191] On the other hand, if the transfer history hash value information does not match any of the stored verified transaction history identification information, the receiving node device 10B-j determines "No" in step S904B of Figure 20 and sets the counter information p to p-1 (in other words, decreases the counter information p by 1) (step S906B of Figure 20). Next, the receiving node device 10B-j returns to step S903B of Figure 20 and repeatedly executes the processes from step S903B to step S906B.

[0192] Furthermore, in step S903B of Figure 20, if the counter information p is equal to 0, the receiving node device 10B-j determines "No" and terminates the process in Figure 20 without executing steps S904B to S906B.

[0193] Subsequently, in step S401 of Figure 19, the receiving node device 10B-j executes the process shown in Figure 21 instead of the process shown in Figure 9. The process shown in Figure 21 is the same as the process in Figure 9, but with step S504B added immediately before step S501.

[0194] In the process shown in Figure 21, first, the receiving node device 10B-j determines whether the number of transactions M is less than the value q+1, which is the verified specific information q plus 1 (step S504B in Figure 21).

[0195] If the number of transactions M is less than q+1, the receiving node device 10B-j determines "Yes" in step S504B of Figure 21 and proceeds to step S502 of Figure 21. As a result, the execution of the process in step S501 of Figure 21 is omitted.

[0196] On the other hand, if the number of transactions M is q+1 or greater, the receiving node device 10B-j determines "No" in step S504B of Figure 21 and proceeds to step S501 of Figure 21.

[0197] Subsequently, in step S403 of Figure 19, the receiving node device 10B-j executes the process shown in Figure 22 instead of the process shown in Figure 10. The process shown in Figure 22 is the same as the process in Figure 10, but with step S601 replaced by steps S608B to S610B.

[0198] In the process shown in Figure 22, first, the receiving node device 10B-j determines whether the verified specific information q is greater than 0 (step S608B in Figure 22).

[0199] If the verified specific information q is greater than 0, the receiving node device 10B-j determines "Yes" in step S608B of Figure 22 and sets the counter information p to the verified specific information q (step S609B of Figure 22). Next, the receiving node device 10B-j executes the processes from step S602 onwards in Figure 22. As a result, the execution of the processes in steps S602 to S605 when the counter information p is 1 to q-1 is omitted.

[0200] On the other hand, if the verified specific information q is 0 or less, the receiving node device 10B-j determines "No" in step S608B of Figure 22 and sets the counter information p to 1 (step S610B of Figure 22). Next, the receiving node device 10B-j executes the processing from step S602 onwards in Figure 22.

[0201] Subsequently, in step S405 of Figure 19, the receiving node device 10B-j executes the process shown in Figure 23 instead of the process shown in Figure 11. The process shown in Figure 23 is the same as the process in Figure 11, but with step S705B added immediately before step S701.

[0202] In the process shown in Figure 23, first, the receiving node device 10B-j determines whether the verified specific information q is greater than 0 (step S705B in Figure 23).

[0203] If the verified specific information q is greater than 0, the receiving node device 10B-j determines "Yes" in step S705B of Figure 23 and proceeds to step S703 of Figure 23. As a result, the execution of steps S701 to S702 of Figure 23 is omitted.

[0204] On the other hand, if the verified specific information q is 0 or less, the receiving node device 10B-j determines "No" in step S705B of Figure 23 and proceeds to step S701 of Figure 23.

[0205] Subsequently, in step S407 of Figure 19, the receiving node device 10B-j executes the process shown in Figure 24 instead of the process shown in Figure 12. The process shown in Figure 24 is the same as the process in Figure 12, but with step S801 replaced by steps S807B to S809B.

[0206] In the process shown in Figure 24, first, the receiving node device 10B-j determines whether the verified specific information q is greater than 0 (step S807B in Figure 24).

[0207] If the verified specific information q is greater than 0, the receiving node device 10B-j determines "Yes" in step S807B of Figure 24 and sets the counter information p to q+1, which is the value obtained by adding 1 to the verified specific information q (step S808B of Figure 24). Next, the receiving node device 10B-j executes the processing from step S802 onwards in Figure 24. As a result, the execution of the processing in steps S802 to S804 when the counter information p is between 1 and q is omitted.

[0208] On the other hand, if the verified specific information q is 0 or less, the receiving node device 10B-j determines "No" in step S807B of Figure 24 and sets the counter information p to 1 (step S809B of Figure 24). Next, the receiving node device 10B-j executes the processing from step S802 onwards in Figure 24.

[0209] As described above, the information processing system 1, a second modified example of the first embodiment, provides the same functions and effects as the information processing system 1 of the first embodiment. Furthermore, in the information processing system 1 of the second modified example of the first embodiment, the second node device (in this example, the receiving node device 10B-j) includes a verified transaction history identification information storage unit 142B.

[0210] The verified transaction history identification information storage unit 142B stores verified transaction history identification information that identifies the transaction history information, which includes a group of transaction information corresponding to the history of token transfers from the time the token is issued up to the transfer represented by the new transaction information, in association with the order of transfers in that history, when the token transfer verification for new transaction information and transaction history information is successful.

[0211] Furthermore, the verification unit (in this example, the transaction information verification unit 126B) omits the execution of the portion of the token transfer verification for the received new transaction information and the received transaction history information that corresponds to the transaction history information identified by the stored verified transaction history identification information.

[0212] According to this, if the second node device receives second transaction history information that includes first transaction history information for which token transfer verification has already been successful, the execution of the part of the token transfer verification corresponding to the first transaction history information is omitted. This reduces the load required to verify the validity of the token transfer. Furthermore, the validity of the token transfer can be verified quickly.

[0213] Furthermore, in the information processing system 1 of the second modified example of the first embodiment, the transaction information includes transfer history hash value information generated by inputting transaction history information, which includes a group of transaction information corresponding to the history of transfers of the token from the time the token is issued up to the transfer immediately preceding the transfer represented by the transaction information, in association with the order of transfers in the history, into a hash function.

[0214] Furthermore, the verified transaction history identification information storage unit 142B uses transfer history hash value information, which is generated by inputting the transaction history information into a hash function, as verified transaction history identification information to identify the transaction history information. Furthermore, the verification unit omits the execution of the portion of the token transfer verification for the received new transaction information and the received transaction history information that corresponds to the history of the token's transfer from the time the token was issued up to the transfer immediately preceding the transfer represented by the transaction information, which includes transfer history hash value information that matches the stored verified transaction history identification information.

[0215] According to this, the second node device can determine which parts of token transfer verification can be omitted by determining whether the received new transaction information, the received transaction history information, the transfer history hash value information contained in it, and the stored verified transaction history identification information match. Therefore, the load required to verify the validity of token transfers can be reduced. In addition, the validity of token transfers can be verified quickly.

[0216] <Second Embodiment> Next, the information processing system of the second embodiment will be described. The information processing system of the second embodiment differs from the information processing system of the first embodiment in that a transfer approval notice is sent from the receiving node device to the awarding node device before new transaction information is recorded in the distributed ledger. The following will focus on the differences. In the description of the second embodiment, reference numerals used in the first embodiment are the same or substantially the same.

[0217] In the information processing system 1 of the second embodiment, the wallet is an SPV (Simplified Payment Verification) wallet.

[0218] (operation) The operation of the information processing system 1 in the second embodiment will be described with reference to Figures 25 and 26. Figure 25 is a sequence diagram showing an example of the operation of the information processing system 1. Figure 26 is a flowchart showing an example of the receiving process performed by the receiving node device 10-j.

[0219] The awarding node device 10-i of the second embodiment performs the awarding process shown in Figure 6, similar to the awarding node device 10-i of the first embodiment. Furthermore, the receiving node device 10-j of the second embodiment performs the process shown in Figure 26 instead of the process shown in Figure 7.

[0220] In the process shown in Figure 26, steps S301 to S303 are the same as steps S301 to S303 in Figure 7. Therefore, the information processing system 1 of the second embodiment performs the processing of steps S101 to S104 in Figure 25 in the same manner as the first embodiment.

[0221] Next, the receiving node device 10-j performs coin transfer verification and token transfer verification (step S105C in Figure 25 and step S304C in Figure 26). In this example, coin transfer verification includes verifying that the coin transfer represented by the new transaction information is a valid transfer of coins issued by the true issuer.

[0222] In this example, the token transfer verification is the same process as the process shown in Figure 8, which is performed by the receiving node device 10-j in the first embodiment. Alternatively, the token transfer verification may be performed by the receiving node device 10A-j in the first modified example of the first embodiment. Furthermore, the token transfer verification may be performed by the receiving node device 10B-j in the second modified example of the first embodiment.

[0223] The receiving node device 10-j sets the transfer verification success information to true if both the coin transfer verification and the token transfer verification are successful, and sets the transfer verification success information to false if at least one of the coin transfer verification or token transfer verification fails. The transfer verification success information indicates whether both the coin transfer verification and the token transfer verification were successful or not.

[0224] Next, the receiving node device 10-j determines whether the transfer verification success information is set to a true value (step S305C in Figure 26). If the transfer verification success information is set to true, the receiving node device 10-j determines "Yes" and broadcasts the new transaction information received in step S303 of Figure 26 to the node device group (step S106 in Figure 25 and step S306 in Figure 26).

[0225] Next, the receiving node device 10-j waits until it receives a reception notification from the node device group (repeatedly determining "No" in step S321C of Figure 26). The reception notification is information indicating that the node device group has received new transaction information.

[0226] Meanwhile, when the node group receives new transaction information from the receiving node device 10-j, it sends a receipt notification to the receiving node device 10-j in response to the receipt of the new transaction information (step S107C in Figure 25). As a result, the receiving node device 10-j receives a receipt notification from the node group (step S107C in Figure 25). Therefore, the receiving node device 10-j determines "Yes" in step S321C in Figure 26 and sends a transfer approval notification to the issuing node device 10-i (step S108C in Figure 25 and step S310 in Figure 26).

[0227] Next, the receiving node device 10-j waits until it receives Merkle proof information from the node device group indicating that new transaction information has been recorded in the distributed ledger (the determination of "No" is repeated in step S322C in Figure 26). In this example, the Merkle proof information is generated using a data structure called a Merkle tree. The Merkle proof information may also be represented as a Merkle proof.

[0228] Subsequently, the node devices verify that the coin transfer represented by the new transaction information is a valid transfer of coins issued by the true issuer, and record the new transaction information in the distributed ledger (step S109C in Figure 25). Next, the node devices generate Merkle certificate information indicating that the new transaction information has been recorded in the distributed ledger, and transmit the generated Merkle certificate information to the receiving node device 10-j (step S110C in Figure 25).

[0229] As a result, the receiving node device 10-j receives Merkle certification information from the node device group (step S110C in Figure 25). Therefore, the receiving node device 10-j determines "Yes" in step S322C in Figure 26, and updates the transaction history information by adding the new transaction information received in step S303 of Figure 26 to the transaction history information received in step S303 of Figure 26, and stores the updated transaction history information (steps S113 in Figure 25 and S311 in Figure 26).

[0230] Next, the receiving node device 10-j returns to step S301 in Figure 26 and repeatedly executes the processes from step S301 onward.

[0231] Furthermore, if the transfer verification success information is set to a false value in step S305C of Figure 26, the receiving node device 10-j determines "No" and sends a transfer failure notification to the awarding node device 10-i (step S312 of Figure 26), and returns to step S301 of Figure 26.

[0232] As described above, the information processing system 1 of the second embodiment provides the same functions and effects as the information processing system 1 of the first embodiment, the first modified example of the first embodiment, or the second modified example of the first embodiment.

[0233] It should be noted that the present invention is not limited to the embodiments described above. For example, various modifications can be made to the embodiments described above that are understandable to those skilled in the art, without departing from the spirit of the present invention. [Explanation of Symbols]

[0234] 1. Information Processing System 10-1, 10-2, ..., 10-N node devices 10A-1, 10A-2, ..., 10A-N node devices 10B-1, 10B-2, ..., 10B-N node devices 10-i Award Node Device 10-j Receiving node device 11 Processing device 12 Memory device 13 Input device 14 Output device 15 Communication device 110 Grant function unit 111 Token transfer condition request transmission unit 112 Token transfer condition information reception unit 113 Transaction information generation unit 114 Transaction information transmission unit 115 Transfer result notification reception unit 120, 120A, 120B Receiving function unit 121 Token transfer condition request reception unit 122 Token transfer condition information transmission unit 123 Transaction information reception unit 124 Issued hash value information acquisition unit 125 Rule information acquisition unit 126, 126A, 126B Transaction information verification unit 127 Broadcast transmission unit 128 Confirmation processing unit 129 Transfer result notification transmission unit 130 Transaction history information storage unit 141A Verified transaction identification information storage unit 142B Verified transaction history identification information storage unit BU Bus NW Communication line

Claims

1. An information processing system in which multiple node devices, each having multiple wallets, communicate in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, The first node device having the first wallet is A generation unit generates new transaction information, which is transaction information representing the transfer of tokens from the first wallet to the second wallet, A transmission unit transmits the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the transfer of the token from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet. Equipped with, The aforementioned second node device, A receiving unit that receives the aforementioned new transaction information and the aforementioned transaction history information, A verification unit performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer. An information processing system equipped with the following features.

2. The information processing system according to claim 1, The transaction information includes the immediate prior transfer hash value information, which is generated by inputting the transaction information representing the transfer immediately preceding the transfer represented by the transaction information into a hash function. The verification unit, An information processing system that performs token transfer verification by performing a sequential verification for each pair of transaction information consisting of two transaction information representing two consecutive transfers, from among a plurality of transaction information consisting of the new transaction information and the group of transaction information included in the transaction history information, by verifying that the hash value information generated by inputting the transaction information representing the preceding transfer into a hash function matches the hash value information of the previous transfer included in the transaction information representing the subsequent transfer.

3. An information processing system according to claim 1 or claim 2, The aforementioned second node device, The system includes an acquisition unit that acquires issuance hash value information generated by inputting transaction information representing the issuance of the aforementioned token into a hash function. The verification unit, An information processing system that performs token transfer verification by performing issuance verification, which verifies that hash value information generated by inputting transaction information included in the transaction history information and representing the issuance of the token into a hash function matches the acquired issuance hash value information.

4. The information processing system according to claim 3, The aforementioned second node device, If the issuance verification of the transaction information is successful, the system includes a verified transaction identification information storage unit that stores verified transaction identification information that identifies the transaction information. The verification unit is an information processing system that omits the execution of the issuance verification for transaction information identified by the stored verified transaction identification information.

5. An information processing system according to claim 1 or claim 2, The transaction information includes token transfer information representing the transfer of the token, The aforementioned second node device, The system includes an acquisition unit that acquires rule information representing the rules followed by the token transfer information included in the transaction information, The verification unit is an information processing system that performs token transfer verification by performing rule verification on each of a plurality of transaction information, consisting of the new transaction information and the transaction information group included in the transaction history information, to verify that the token transfer information included in the transaction information conforms to the rules represented by the acquired rule information.

6. The information processing system according to claim 5, The aforementioned second node device, If the rule validation against the transaction information is successful, the system includes a validated transaction identification information storage unit that stores validated transaction identification information that identifies the transaction information. The verification unit is an information processing system that omits the execution of rule verification on transaction information identified by the stored verified transaction identification information.

7. An information processing system according to claim 1 or claim 2, The verification unit is an information processing system that performs token transfer verification by performing record verification, which verifies that transaction information included in the transaction history information and representing the transfer immediately preceding the transfer represented by the new transaction information is recorded in the distributed ledger.

8. An information processing system according to claim 1 or claim 2, The aforementioned second node device, If the token transfer verification for the new transaction information and the transaction history information is successful, the system includes a verified transaction history identification information storage unit that stores verified transaction history identification information that identifies transaction history information including a group of transaction information corresponding to the history of the transfer of the token from the time the token was issued up to the transfer represented by the new transaction information, in association with the order of transfers in the history. The verification unit is an information processing system that omits the execution of the portion of the token transfer verification for the received new transaction information and the received transaction history information that corresponds to the transaction history information identified by the stored verified transaction history identification information.

9. The information processing system according to claim 8, The transaction information includes a transfer history hash value information generated by inputting transaction history information, which includes a set of transaction information corresponding to the transfer history of the token from the time the token was issued up to the transfer immediately preceding the transfer represented by the transaction information, in association with the order of transfers in that history, into a hash function. The verified transaction history identification information storage unit uses, as the verified transaction history identification information for identifying the transaction history information, transfer history hash value information generated by inputting the transaction history information into a hash function, The verification unit is an information processing system that omits the execution of the portion of the token transfer verification for the received new transaction information and the received transaction history information that corresponds to the history of the token's transfer from the time the token was issued up to the transfer immediately preceding the transfer represented by the transaction information including the transfer history hash value information that matches the stored verified transaction history identification information.

10. An information processing system according to claim 1 or claim 2, The aforementioned second node device, An information processing system comprising a transmission unit that, if the token transfer verification is successful, transmits the new transaction information by broadcast, while, if the token transfer verification fails, does not transmit the new transaction information.

11. An information processing method in which multiple node devices having multiple wallets communicate in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, A first node device having a first wallet generates new transaction information, which is transaction information representing the transfer of a token from the first wallet to the second wallet. The first node device transmits the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the transfer of the token from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet. The second node device receives the new transaction information and the transaction history information, The second node device performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer. Information processing methods, including the act of processing information.

12. In an information processing system in which multiple node devices having multiple wallets communicate in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, the first node device having a first wallet, A generation unit that generates new transaction information which is transaction information representing the transfer of tokens from the first wallet to the second wallet, A transmission unit transmits the newly generated transaction information and transaction history information, which includes a group of transaction information corresponding to the history of the transfer of the token from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, to the second node device having the second wallet. A first node device equipped with the following:

13. In an information processing system in which multiple node devices having multiple wallets communicate in a peer-to-peer manner to record transaction information representing the transfer of tokens associated with coins between two of the multiple wallets in a distributed ledger composed of a blockchain, the second node device having a second wallet, A receiving unit that receives from a first node device having the first wallet new transaction information which is transaction information representing the transfer of a token from the first wallet to the second wallet, and transaction history information which includes a group of transaction information corresponding to the history of the transfer of the token from the time the token was issued up to the transfer immediately preceding the transfer represented by the new transaction information, in association with the order of transfers in that history, A verification unit performs token transfer verification based on the received new transaction information and the received transaction history information to verify that the transfer of the token to the second wallet is a valid transfer of the token issued by the true issuer. A second node device equipped with the following.

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