Patent Publication Number: US-2021182861-A1

Title: Method and system for fraud control of blockchain-based transactions

Description:
FIELD (P02012/419) 
     The present disclosure relates to the linking of blockchain transactions to privately verified identities, specifically the association of a blockchain transaction to a consumer or merchant associated with a transaction account based on transaction data and stored account profiles. 
     BACKGROUND 
     In recent times, blockchain currencies have seen increased usage over traditional fiat currencies by consumers who value anonymity and security. Currencies that use a blockchain, such as cryptographic currencies (“cryptocurrencies”), offer consumers a currency that is decentralized and relatively anonymous and secure in its use. For example, a transaction that is posted to a blockchain may not require any information regarding the sender or recipient of the currency, and thus may enable the payer and payee of a transaction to retain anonymity. Such an aspect of blockchain transactions may be highly desirable for consumers that wish to maintain their privacy, and may help reduce the likelihood of fraud due to theft of their information. 
     However, while blockchain currencies can often provide such safety and security for the payer&#39;s information, such security may be limited for payees, particularly due to the limitations of the blockchain. For example, it often takes a significant amount of time, around ten minutes, for a blockchain-based transaction to be processed, due to the computer processing time and resources required to verify and update the blockchain. Conversely, traditional fiat payment transactions that are processed using payment networks often have processing times that are measured in nanoseconds. As a result, consumers and merchants that are accustomed to fast transaction times are often either forced to wait a significant amount of time for a blockchain transaction to be conducted, or the payee must rely on the payer&#39;s good faith that their transfer will be valid. In such latter instances, the anonymity of the blockchain may leave the payee at a disadvantage, because the inability for the payee to identify the payer may prohibit the payee from utilizing various risk or fraud detection methods. Therefore, many entities, particularly merchants, retailers, service providers, and other purveyors of goods and services, may be wary of accepting blockchain currency for products and participating in blockchain transactions. 
     In addition, the consumers themselves may often be reluctant to using blockchain currencies. Because blockchain currencies are decentralized and rely on the blockchain to keep track of what accounts have access to what amount of currency, it can be difficult for consumers to adopt, or even understand, blockchain currencies, particularly in relation to well-known and understood traditional fiat currencies and accounts. This may be particularly troublesome for consumers that are accustomed to having financial institutions hold their currency in an account. The nature of blockchain currencies is that the access to any given address to which currency is associated is controlled based on possession of electronic credentials, often referred to as an electronic wallet, e-wallet, or simply “wallet.” As such, if the wallet is lost, discarded, or stolen, the associated currency often cannot be recovered by the rightful owner and may be used without their knowledge and permission. Furthermore, because of the anonymous nature of the blockchain, the consumer may be unable to prove their identity and ownership of a wallet, and thereby have little recourse if their wallet and/or associated currency is stolen. 
     Thus, there is a need to improve on the storage and processing of transactions that utilize blockchain currencies. Existing payment networks and payment processing systems that utilize fiat currency are specially designed and configured to safely store and protect consumer and merchant information and credentials and to transmit sensitive data between computing systems. In addition, existing payment systems are often configured to perform complex calculations, risk assessments, and fraud algorithm applications extremely fast, as to ensure quick processing of fiat currency transactions. Accordingly, the use of traditional payment networks and payment systems technologies in combination with blockchain currencies may provide consumers and merchants the benefits of the decentralized blockchain while still maintaining security of account information and provide a strong defense against fraud and theft. 
     SUMMARY 
     The present disclosure provides a description of systems and methods for linking blockchain transactions to privately verified identities. 
     A method for linking blockchain transactions to privately verified identities includes: storing, in an account database, a plurality of account profiles, wherein each account profile includes data related to a transaction account including at least an account identifier and account data; receiving, by a receiving device, a transaction message, wherein the transaction message is formatted based on one or more standards and includes a plurality of data elements including at least a first data element configured to store a personal account number, a second data element configured to store a merchant identifier, and a third data element configured to store at least a blockchain network identifier; identifying, by a processing device, a first account profile stored in the account database where the included account identifier corresponds to the personal account number stored in the first data element included in the received transaction message; identifying, by the processing device, a second account profile stored in the account database where the included account identifier corresponds to the merchant identifier stored in the second data element included in the received transaction message; receiving, by the receiving device, a transaction notification, wherein the transaction notification indicates a transaction processed using a blockchain network associated with the blockchain network identifier stored in the third data element included in the received transaction message and includes at least a transaction identifier and an address identifier associated with one of the first account profile and the second account profile; and storing, by the processing device, a linkage between the transaction identifier included in the received transaction notification and at least one of: the address identifier, the personal account number, and the merchant identifier. 
     A system for linking blockchain transactions to privately verified identities includes an account database, a receiving device, and a processing device. The account database is configured to store a plurality of account profiles, wherein each account profile includes data related to a transaction account including at least an account identifier and account data. The receiving device is configured to receive a transaction message, wherein the transaction message is formatted based on one or more standards and includes a plurality of data elements including at least a first data element configured to store a personal account number, a second data element configured to store a merchant identifier, and a third data element configured to store at least a blockchain network identifier. The processing device is configured to: identify a first account profile stored in the account database where the included account identifier corresponds to the personal account number stored in the first data element included in the received transaction message; and identify a second account profile stored in the account database where the included account identifier corresponds to the merchant identifier stored in the second data element included in the received transaction message. The receiving device is further configured to receive a transaction notification, wherein the transaction notification indicates a transaction processed using a blockchain network associated with the blockchain network identifier stored in the third data element included in the received transaction message and includes at least a transaction identifier and an address identifier associated with one of the first account profile and the second account profile. The processing device is further configured to store a linkage between the transaction identifier included in the received transaction notification and at least one of: the address identifier, the personal account number, and the merchant identifier. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The scope of the present disclosure is best understood from the following detailed description of exemplary embodiments when read in conjunction with the accompanying drawings. Included in the drawings are the following figures: 
         FIG. 1  is a block diagram illustrating a high level system architecture for managing blockchain currency storage and linkage thereof to privately verified identifies and use thereof in the processing of blockchain transactions using payment networks in accordance with exemplary embodiments. 
         FIG. 2  is a block diagram illustrating the processing server of  FIG. 1  for authorizing blockchain transactions and linking blockchain transactions to privately verified identifies in accordance with exemplary embodiments. 
         FIG. 3  is a block diagram illustrating the issuer of  FIG. 1  for managing fractional reserves of fiat and blockchain currency in accordance with exemplary embodiments. 
         FIG. 4  is a flow diagram illustrating a process for authorizing a blockchain transaction using a transaction message and a payment network in accordance with exemplary embodiments. 
         FIG. 5  is a flow diagram illustrating a process for the authorization of a blockchain transaction using the processing server of  FIG. 2  in accordance with exemplary embodiments. 
         FIG. 6  is a diagram illustrating the generation of an invoice for inclusion in a reserve data element of a transaction message containing blockchain transaction details in accordance with exemplary embodiments. 
         FIG. 7  is a flow diagram illustrating a process for linking blockchain transaction data to privately verified identities in accordance with exemplary embodiments. 
         FIG. 8  is a flow diagram illustrating a process for the management of fractional reserves of fiat and blockchain currency in accordance with exemplary embodiments. 
         FIG. 9  is a flow diagram illustrating a process for authorization of a blockchain transaction based on an identified risk value in accordance with exemplary embodiments. 
         FIG. 10  is a flow chart illustrating an exemplary method for authorization of a blockchain-based transaction in accordance with exemplary embodiments. 
         FIG. 11  is a flow chart illustrating an exemplary method for linking blockchain transactions to privately verified identifies in accordance with exemplary embodiments. 
         FIG. 12  is a flow chart illustrating an exemplary method for managing fractional reserves of blockchain currency in accordance with exemplary embodiments. 
         FIG. 13  is a flow chart illustrating an exemplary method for authorizing a blockchain transaction using risk values in accordance with exemplary embodiments. 
         FIG. 14  is a block diagram illustrating a computer system architecture in accordance with exemplary embodiments. 
     
    
    
     Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description of exemplary embodiments are intended for illustration purposes only and are, therefore, not intended to necessarily limit the scope of the disclosure. 
     DETAILED DESCRIPTION 
     Glossary of Terms 
     Payment Network—A system or network used for the transfer of money via the use of cash-substitutes. Payment networks may use a variety of different protocols and procedures in order to process the transfer of money for various types of transactions. Transactions that may be performed via a payment network may include product or service purchases, credit purchases, debit transactions, fund transfers, account withdrawals, etc. Payment networks may be configured to perform transactions via cash-substitutes, which may include payment cards, letters of credit, checks, transaction accounts, etc. Examples of networks or systems configured to perform as payment networks include those operated by MasterCard®, VISA®, Discover®, American Express®, PayPal®, etc. Use of the term “payment network” herein may refer to both the payment network as an entity, and the physical payment network, such as the equipment, hardware, and software comprising the payment network. 
     Transaction Account—A financial account that may be used to fund a transaction, such as a checking account, savings account, credit account, virtual payment account, etc. A transaction account may be associated with a consumer, which may be any suitable type of entity associated with a payment account, which may include a person, family, company, corporation, governmental entity, etc. In some instances, a transaction account may be virtual, such as those accounts operated by PayPal®, etc. 
     Blockchain—A public ledger of all transactions of a blockchain-based currency. One or more computing devices may comprise a blockchain network, which may be configured to process and record transactions as part of a block in the blockchain. Once a block is completed, the block is added to the blockchain and the transaction record thereby updated. In many instances, the blockchain may be a ledger of transactions in chronological order, or may be presented in any other order that may be suitable for use by the blockchain network. In some configurations, transactions recorded in the blockchain may include a destination address and a currency amount, such that the blockchain records how much currency is attributable to a specific address. In some instances, additional information may be captured, such as a source address, timestamp, etc. 
     System for Use of Blockchain Currency in a Payment Network 
       FIG. 1  illustrates a system  100  for the managing of blockchain and fiat currency and use thereof in payment transactions using a traditional payment network, including the linkage of verified identifies to blockchain-based transactions and assessing of risk in blockchain-based transactions. 
     In the system  100 , a blockchain transaction may occur between the computing device of a payer  102  and the computing device of a payee  104 . As used herein, “payer” may refer to a computing device and/or a consumer that is funding a payment transaction, and “payee” may refer to a computing device and/or a consumer that is receiving payment in a payment transaction. The blockchain transaction may be processed by one or more computing devices that comprise a blockchain network  106 . The blockchain network may receive at least a destination address (e.g., associated with the payer  104 ) and an amount of blockchain currency and may process the transaction by generating a block that is added to a blockchain that includes a record for the transaction. 
     The computing device of the payer  102  may digitally sign the transaction request using an encryption key stored in the computing device, such as stored in an electronic wallet. The digital signature may be, include, or otherwise be associated with an address that is generated using the encryption key, which may be associated with blockchain currency in the blockchain, and may be used to transfer blockchain currency to an address associated with the payee  104  and/or their computing device. In some embodiments, the address may be encoded using one or more hashing and/or encoding algorithms, such as the Base 58 Check encoding algorithm. The generation and use of addresses for the transfer of blockchain currency in blockchain-based transactions using the blockchain network  106  will be apparent to persons having skill in the relevant art. 
     The system  100  may also include a payment network  108 . The payment network  108  may be configured to process payment transactions using methods and systems that will be apparent to persons having skill in the relevant art. In the system  100 , the payment network  108  may also include a processing server  110 . The processing server  110 , discussed in more detail below, may be configured to authorize blockchain-based transactions using the payment network  108  and traditional payment rails, may be configured to link blockchain transactions with privately verified identities including fiat and/or blockchain transaction accounts, and may be configured to provide risk and sanction assessments for blockchain transactions. 
     The payer  102  may be associated with an issuer  112 . The issuer  112 , discussed in more detail below, may be a computing system of a financial institution, such as an issuing bank, that issues one or more transaction accounts to the payer  102 . The transaction accounts may include one or more fiat currency transaction accounts, one or more blockchain currency transaction accounts, one or more combined currency transaction accounts, or any combination thereof. For example, the payer  102  may have a transaction account with the issuer  112  for both fiat and blockchain currency, and an additional fiat currency transaction account. 
     The payee  104  may be associated with an acquirer  114 . The acquirer  114  may be a computing system of a financial institution, such as an acquiring bank, that issues one or more transaction accounts to the payee  104 . The acquirer  114  may be the equivalent of the issuer  112 , but with respect to the payee  104  rather than the payer  102 . In some instances, the issuer  112  and the acquirer  114  may be the same financial institution. For example, the issuer  112  may provide transaction accounts to both the payer  102  and the payee  104 . 
     The payer  102  may conduct a blockchain transaction with the payee  104 . As part of the blockchain transaction, the payee  104  may generate a destination address for receipt of payment of blockchain currency. The destination address may be generated using an encryption key stored in the computing device of the payee  104 . The encryption key may be part of a key pair, such as a public key corresponding to a private key stored in the computing device. In some instances, the payee  104  may provide the public key to the payer  102 , and the payer  102  may generate the destination address. A transaction request may then be submitted by the payer  102  for payment of an agreed-upon blockchain currency amount to the destination address provided by the payee  104 . In a traditional blockchain transaction, the transaction request may be submitted by the computing device to the blockchain network  106 . In the present system  100 , the transaction request may be submitted to the processing server  110  of the payment network  108 . 
     The transaction request may be a transaction message and may be formatted based on one or more standards for the governance thereof, such as the International Organization for Standardization&#39;s ISO 8583 standard. In some instances, the processing server  110  may receive the transaction request and may generate a subsequent transaction message. The transaction message may include a plurality of data elements, which may be associated with specific usage based on the one or more standards. For example, the data elements may include a data element for the storage of transaction amount and also include at least one data element reserved for private use. In the system  100 , the transaction message submitted to the processing server  110  may include a data element reserved for private use that includes data associated with the desired blockchain transaction. 
     For instance, the data element reserved for private use may include a network identifier, a transaction amount, and at least one of: a public key and an address identifier. The network identifier may be associated with a blockchain network  106  associated with the blockchain currency being transferred in the transaction. The network identifier may be used by the processing server  110  to identify the associated blockchain network  106  for posting of the eventual blockchain transaction. In addition, by using different identifiers, the processing server  110  may be configured to perform the functions discussed herein for a plurality of different blockchain currencies and associated blockchain networks  106 . 
     The transaction amount may be an amount of blockchain currency being transferred as a result of the transaction. The address identifier may be the destination address for the blockchain currency, as provided by the payee  104  or generated by the payer  102  using information provided by the payee  104  (e.g., their public key). In instances where the data element includes a public key (e.g., associated with the payee  104 ) instead of an address identifier, the processing server  110  may be configured to generate an address identifier using the public key. In some instances, the address identifier may be encoded using one or more hashing and/or encoding algorithms, such as the Base 58 Check algorithm. 
     In some embodiments, the transaction message may include information for multiple payees  104 . In such an embodiment, the data element reserved for private use may include multiple transaction amounts and associated address identifiers and/or public keys. In another embodiment, the transaction message may include multiple data elements reserved for private use, with each one including a transaction amount and a different address identifier and/or public key associated with a payee  104 . In some instances, one of the payees  104  may be the payer  102 . For example, the blockchain transaction may include a remainder amount of blockchain currency to be retained by the payer  102 , and may thereby include a transfer from an input address to a destination address of the payer  102 , as will be apparent to persons having skill in the relevant art. 
     In some embodiments, the data element reserved for private use, or an alternative data element reserved for private use in the transaction message, may include input information associated with the payer  102 . The input information may include a transaction identifier associated with a prior blockchain transaction as well as a public key associated with the payer  102  and a digital signature. The digital signature may be generated using a private key corresponding to the public key and may be used for verification of ownership of a blockchain currency amount associated with the transaction identifier by the payer  102 , such that the payer  102  is authorized to transfer the blockchain currency in the requested transaction. 
     In some instances, the transaction message may be submitted to the processing server  110  by the payer  102 . In other instances, the payer  102  may provide the transaction information to the issuer  112 , which may generate and submit the transaction message to the processing server  110 . Once the transaction message is received by the processing server  110 , the processing server  110  may perform additional functions, such as an assessment of risk or sanctions as discussed in more detail below. A corresponding blockchain transaction may then be processed using the blockchain network  106  based on the information included in the data element(s) reserved for private use. In some embodiments, the blockchain transaction may be initiated by the processing server  110 . In other embodiments, the processing server  110  may provide the transaction message or data included therein to the issuer  112 , which may initiate the blockchain transaction, such as after evaluating risk for the transaction, assessing if the payer  102  has sufficient blockchain currency for the transaction, and etc., as discussed below. 
     For instance, as discussed in more detail below, the issuer  112  may manage fractional reserves of fiat and blockchain currency, which may include the storage of currencies associated with the payer  102 . The issuer  112  may store a transaction account of blockchain currency associated with the payer  102  such that, when a transaction is attempted by the payer  102 , the issuer  112  may verify the available funds of the payer  102  prior to initiating the blockchain transaction, which may be before submitting the transaction message to the processing server  110  and/or before submitting a transaction request to the blockchain network  106 . 
     In another example, the issuer  112  may assess a risk for the transaction based on an evaluation provided by the processing server  110  or performed by the issuer  112 , such as based on the payer&#39;s available funds, credit history, or other fraud, sanction, and/or risk considerations that will be apparent to persons having skill in the relevant art. In some embodiments, the acquirer  114  may assess a risk for the transaction prior to processing by the blockchain network  106 . For instance, the acquirer  114  may evaluate the reliability of the payer  102 , an expectation of fraud, etc. based on data provided by the issuer  112 , processing server  110 , or third party entity, as discussed in more detail below. In some instances, the payer  102  may decline the use of chargeback or payment protection in exchange for a discount offered by the payee  104  (e.g., a merchant), which may be beneficial for the merchant  104  as a result of reduced fees. In other instances, the payee  104  may decline the use of risk assessments and other protections for a transaction. 
     In some embodiments, the issuer  112  and/or processing server  110  may be further configured to store private keys on behalf of payers  102  and/or payees  104 . In such embodiments, the private key may be stored such that the issuer  112  and/or processing server  110  may initiate and digitally sign blockchain transactions on behalf of a payer  102  such that the payer  102  does not need to retain possession of a computing device for use in blockchain transactions. For example, the issuer  112  may store the private key on behalf of the payer  102  and any transaction identifiers associated with the payer  102  (e.g., in their blockchain currency account) and may be configured to generate the digital signature and include the generated signature and transaction identifier in transaction messages for blockchain transactions involving the payer  102 . 
     In some embodiments, the processing server  110  may be further configured to link blockchain transactions with privately verified identities, such as with the payer  102 , payee  104 , or transaction accounts associated thereof. For example, the processing server  110  may store account information for transaction accounts associated with the payer  102  (e.g., held by the issuer  112 ) and the payee  104  (e.g., held by the acquirer  114 ), which may include address identifiers. The processing server  110  may then associate blockchain transactions with the stored account information using the account identifiers included therein and account identifiers included in data elements in received transaction messages. The processing server  110  may thereby store historical transaction data for individuals for blockchain transactions. In instances where an individual may have a combined fiat and blockchain currency account, the processing server  110  may, as a result, store transaction history for a consumer&#39;s fiat and blockchain transactions. 
     The methods and systems discussed herein accordingly provide for the processing of blockchain transactions using transaction messaging and traditional payment networks, which may be provide significant benefits to consumers and financial institutions that are currently unavailable in blockchain transactions. By using traditional payment rails and transaction messages, which are highly regulated and secure, transaction information may be transmitted at a higher level of security than methods currently used in blockchain transactions. In addition, the storage of private keys in financial institutions and/or payment networks may enable consumers to engage in blockchain transactions without being in constant possession of a computing device that stores their private keys. This may reduce the risk of theft of the consumer&#39;s blockchain currency by trusting the data to financial institutions and payment networks that already specialize in the storage of sensitive financial information, and that are well equipped to transmit and analyze transaction messages. 
     In addition, by processing blockchain transactions using payment networks, payment networks may be able to evaluate the likelihood of fraud and assess risk for blockchain transactions using existing fraud and risk algorithms and information that is available to payment networks, such as historical fiat and blockchain transaction data, credit bureau data, demographic information, etc., that is unavailable for use in blockchain networks  106 . As a result, payers  102  and payees  104  may engage in blockchain transactions with added safeguards against fraud and risk. In addition, the evaluation of risk may be used by a financial institution to provide the consumer with funds or an indication of thereof to a payee (e.g., a merchant supplying a product to the payer) without waiting for the significantly long processing time of traditional blockchain transactions. 
     For example, a consumer may want to use a blockchain currency to pay for a product at a merchant. In a traditional blockchain transaction, the merchant must wait at least ten minutes for the transaction to be verified (e.g., and the merchant assured of the consumer&#39;s ability to pay) or risk providing the product and not receiving payment. By using the methods and systems discussed herein, the merchant&#39;s acquirer may be able to evaluate the risk of the transaction to determine if the product should be provided prior to waiting for verification of the blockchain transaction. In addition, if a financial institution stores the blockchain currency for the consumer, the financial institution, a trusted and verified entity, can ensure to the acquirer that the consumer has sufficient funds, so that the merchant can provide the product to the consumer immediately. Furthermore, if the financial institution manages fractional reserves for the blockchain currency, the financial institution can immediately update the consumer&#39;s available currency accordingly, such that the consumer can engage in a series of transactions without waiting for blockchain network verification. 
     Therefore, the methods and systems discussed herein can provide for significant improvement over the traditional processing of blockchain transactions via the use of fractional reserves, transaction messages, risk evaluation, and payment network processing, by increasing consumer security, significantly decreasing processing time, and providing significantly increased defense against fraud. 
     Processing Server 
       FIG. 2  illustrates an embodiment of the processing server  110  of the system  100 . It will be apparent to persons having skill in the relevant art that the embodiment of the processing server  110  illustrated in  FIG. 2  is provided as illustration only and may not be exhaustive to all possible configurations of the processing server  110  suitable for performing the functions as discussed herein. For example, the computer system  1400  illustrated in  FIG. 14  and discussed in more detail below may be a suitable configuration of the processing server  110 . 
     The processing server  110  may include a receiving unit  202 . The receiving unit  202  may be configured to receive data over one or more networks via one or more network protocols. The receiving unit  202  may be configured to receive transaction messages from issuers  112 , acquirers  114 , payers  102 , and other entities that are formatted pursuant to one or more standards for the interchange of transaction messages, such as the ISO 8583 standard, and using communication protocols associated thereby. The receiving unit  202  may also receive transaction requests from issuers  112 , acquirers  114 , and/or payers  102 . The receiving unit  202  may also be configured to receive account information for transaction accounts, which may include fiat currency and blockchain currency accounts, from financial institutions, such as the issuer  112  and the acquirer  114 . The receiving unit  202  may be further configured to receive any additional data suitable for performing the functions disclosed herein, such as data that may be used in the risk assessment of a blockchain transaction, such as credit bureau information, demographic characteristics, etc. 
     The processing server  110  may also include a processing unit  204 . The processing unit  204  may be configured to perform the functions of the processing server  110  discussed herein as will be apparent to persons having skill in the relevant art. When a transaction request for a blockchain transaction is received by the receiving unit  202 , the processing unit  204  may be configured to identify data included in the transaction request and generate a transaction message based thereon. The transaction message may be generated for compliance with one or more standards, such as the ISO 8583 standard, and may include a plurality of data elements. The data elements may include a data element configured to store a transaction amount and a data element reserved for private use. The processing unit  204  may be configured to store a zero value in the data element configured to store a transaction amount, and may be configured to store at least a network identifier or encoded value based thereon, an address identifier, and a transaction amount in the data element reserved for private use. 
     In some embodiments, the processing unit  204  may be further configured to generate the address identifier. In such an embodiment, the processing unit  204  may use a public key included in the received transaction request to generate a destination address. The destination address may be the address identifier, or, in some instances, the destination address may be encoded using one or more hashing and/or encoding algorithms, such as Base 58 Check encoding, to generate the address identifier. 
     The processing server  110  may also include a transmitting unit  206 . The transmitting unit  206  may be configured to transmit data over one or more networks via one or more network protocols. The transmitting unit  206  may transmit data requests to the issuer  112 , acquirer  114 , payer  102 , or other entities. The transmitting unit  206  may also be configured to transmit generated transaction messages to financial institutions, such as the issuer  112  and the acquirer  114 , using the payment network  106 . In some embodiments, the transmitting unit  206  may also transmit blockchain transaction requests to blockchain networks  106  based on information received by the receiving unit  202  and generated by the processing unit  204  for use in blockchain transactions. For example, the transmitting unit  206  may transmit a transaction message to the issuer  112 , which may approve the corresponding blockchain transaction as indicated in an approval received by the receiving unit  202 . The transmitting unit  206  may then transmit the blockchain transaction to the blockchain network  106  using methods and systems that will be apparent to persons having skill in the relevant art. 
     In some embodiments, the processing server  110  may also include an account database  208 . The account database  208  may be configured to store a plurality of account profiles  210 . Each account profile  210  may include data related to a consumer (e.g., the payer  102 , payee  104 , etc.) or a transaction account associated thereof, including at least an account identifier, a fiat currency amount, and one or more blockchain currency amounts. Each blockchain currency amount may be associated with a blockchain network  106 . The account identifier may be a unique value associated with the account profile  210  used for identification thereof, such as a transaction account number, wallet identifier, device identifier, username, e-mail address, phone number, etc. In some embodiments, the account identifier may be a private key. The account profile  210  may also include a plurality of associated address identifiers used in blockchain transactions associated with the related consumer and/or transaction account. 
     In such an embodiment, the receiving unit  202  may be further configured to receive a transaction message for a blockchain transaction. The transaction message may include a data element configured to store a personal account number that includes a specific account identifier and a data element reserved for private use that includes at least a network identifier and a transaction amount. The processing unit  204  may be configured to identify a specific account profile  210  stored in the account database  208  that includes the specific account identifier. The processing unit  204  may be further configured to identify a risk value for the blockchain transaction. The risk value may be based on the transaction amount included in the data element reserved for private use and data included in the identified specific account profile  210 . 
     For example, the risk value may be based on a correspondence between the transaction amount and a blockchain currency amount of the specific account profile  210  that is associated with a blockchain network  106  corresponding to the network identifier included in the data element reserved for private use. In some instances, the risk value may also be based on a corresponding amount of fiat currency, such as based on one or more conversion rates associated with conversion of the fiat currency to/from the respective blockchain currency. 
     The processing unit  204  may be further configured to determine authorization of the blockchain transaction based on the identified risk value. For example, if the processing unit  204  identifies that the blockchain transaction has a high risk value (e.g., indicating a high likelihood of fraud, sanctions, inability to pay, etc.), the processing unit  204  may determine that the transaction should be denied. The processing unit  204  may modify the transaction message to include the determination, and the transmitting unit  206  may be configured to transmit the transaction message to the issuer  112  and/or acquirer  114 . The financial institution may then proceed in the processing of the transaction accordingly based on the determination. As part of the processing, the receiving unit  202  may receive an authorization response from the financial institution, and the transmitting unit  206  may forward the response as a reply to the received transaction message, and may also (e.g., if the transaction is approved) initiate the blockchain transaction with the blockchain network  106 . 
     In some embodiments, the processing unit  204  may be further configured to link blockchain transactions with account profiles  210  stored in the account database  208 . In such an embodiment, transaction messages received by the receiving unit  202  for blockchain transactions may include at least a first data element configured to store a personal account number, a second data element configured to store a merchant identifier, and a third data element, which may be reserved for private use, configured to store at least blockchain network identifier. The processing unit  204  may identify a first account profile  210  where the included account identifier corresponds to the personal account number and a second account profile  210  where the included account identifier corresponds to the merchant identifier. 
     The receiving unit  202  may also receive a transaction notification indicative of a blockchain transaction processed using a blockchain network  106  associated with the blockchain network identifier included in the third data element of the received transaction message. The transaction notification may include at least a transaction identifier and an address identifier. The address identifier may be associated with the identified first account profile  210  or the identified second account profile  210 . The processing unit  204  may then store a linkage between the transaction identifier and the account identifier included in the account profile  210  associated with the address identifier. In some instances, the linkage may be stored via storage of the transaction identifier in the corresponding account profile  210 , which may thereby be used in future blockchain transactions involving the associated transaction account. In some instances, the transmitting unit  206  may transmit the transaction identifier to a financial institution associated with the linked account, such that the financial institution may store the transaction identifier for use in future blockchain transactions. In some cases, the processing unit  204  may store transaction data included in the transaction message in the first and/or second account profiles  210 . 
     In some embodiments, the processing server  110  may further include a transaction database  212 . The transaction database  212  may be configured to store a plurality of transaction data entries  214 . Each transaction data entry  214  may include data related to a payment transaction, which may be a fiat currency transaction or a blockchain currency transaction. Each transaction data entry  214  may include a transaction message, transaction notification, and/or data included therein, such as transaction times and/or dates, transaction identifiers, source addresses, destination addresses, transaction amounts, merchant data, consumer data, product data, loyalty data, reward data, etc. In some instances, transaction data entries  214  may be stored in an account profile  210  related to a transaction account involved in the associated payment transaction. 
     The processing server  110  may also include a memory  216 . The memory  216  may be configured to store data suitable for use by the processing server  110  in performing the functions disclosed herein. For example, the memory  216  may store one or more hashing algorithms for encoding address identifiers, one or more rules for the generation of address identifiers, blockchain network data, rules and/or algorithms for calculating risk values, fiat and blockchain currency conversion algorithms or data, etc. Additional data that may be stored in the memory  216  will be apparent to persons having skill in the relevant art. 
     Financial Institution 
       FIG. 3  illustrates an embodiment of a financial institution of the system  100 , such as the issuer  112 . It will be apparent to persons having skill in the relevant art that the embodiment of the issuer  112  illustrated in  FIG. 3  is provided as illustration only and may not be exhaustive to all possible configurations of the issuer  112  suitable for performing the functions as discussed herein. For example, the computer system  1400  illustrated in  FIG. 14  and discussed in more detail below may be a suitable configuration of the issuer  112 . 
     The issuer  112  may include a central database  308 . The central database  308  may be configured to store a plurality of central accounts  310 . Each central account  310  may be associated with a type of currency and may include a corresponding currency amount. For instance, the issuer  112  may include at least a first central account  310  associated with a fiat currency and including a fiat currency amount and a second central account  310  associated with a blockchain currency and including a blockchain currency amount. 
     The issuer  112  may also include an account database  312 . The account database  312  may be configured to store a plurality of account profiles  314 . Each account profile  314  may be configured to store data related to a consumer (e.g., the payer  102 ) or a transaction account including at least a fiat currency amount, a blockchain currency amount, an account identifier, and one or more addresses. Each address may be associated with the account profile  314  and used as a destination address in the transfer of blockchain currency to the related consumer and/or transaction account. 
     The issuer  112  may further include a receiving unit  302 . The receiving unit  302  may be configured to receive data over one or more networks via one or more network protocols. The receiving unit  302  may receive addresses from payers  102 , payees  104 , acquirers  114 , processing servers  110 , etc., which may be stored in respective account profiles  314 . The receiving unit  302  may also be configured to receive transaction messages related to payment transactions. The transaction messages may be formatted pursuant to one or more standards, such as the ISO 8583 standard, and may be communicated to the issuer  112  using associated communication protocols and communication channels, such as the payment network  108  and/or associated payment rails. The transaction messages may include a plurality of data elements, including at least a data element reserved for private use that includes a specific address and a transaction amount. 
     The issuer  112  may also include a processing unit  304 . The processing unit  304  may be configured to perform the functions of the issuer  112  discussed herein as will be apparent to persons having skill in the relevant art. The processing unit  304  may identify a specific account profile  314  stored in the account database that includes the address included in the received transaction message. The processing unit  304  may then update the blockchain currency amount included in the identified account profile  314  based on the transaction amount included in the data element reserved for private use in the received transaction message. The processing unit  304  may also update the blockchain currency amount in the central account  310  in the central database  308  associated with the blockchain currency. 
     In instances where a transaction account related to an account profile  314  that is stored in the account database  312  may be used to fund a blockchain transaction, the processing unit  304  may be configured to deduct the transaction amount from the blockchain currency amount in the identified account profile  314 . The processing unit  304  may also update the blockchain currency amount included in the corresponding central account  310  stored in the central database  308 . The processing unit  304  may be further configured to perform the same functions using fiat currencies or additional numbers and/or types of blockchain currencies. 
     In some embodiments, each account profile  314  may be further configured to store one or more encryption keys, such as a private and public key pair. In such an embodiment, the processing unit  304  may be configured to generate addresses using the public key stored in an account profile  314 , for use as a destination address in a blockchain transaction. The processing unit  304  may also be configured to provide digital signatures for the transfer of blockchain currency from a specific account profile  314  using the private key included therein. 
     In some embodiments, the issuer  112  may be further configured to initiate blockchain transactions using the payment network  108 . In such an embodiment, the receiving unit  302  may receive a transaction request from a payer  102 . The transaction request may include at least a destination address (e.g., associated with the payee  104 ), a network identifier, a blockchain currency amount, and an account identifier. The processing unit  304  may identify an account profile  314  that includes the account identifier. In some instances, the processing unit  304  may verify that the account profile  314  includes a sufficient amount of blockchain currency to support the transaction prior to proceeding. The processing unit  304  may identify a transaction identifier, address, or other identifier for use in providing funding in the blockchain transaction, based on the data stored in the identified account profile  314 . The processing unit  304  may also generate a digital signature using the private key stored therein. In some instances, the digital signature may be included in the received transaction request. 
     The processing unit  304  may then generate a transaction message. The transaction message may include a data element reserved for private use that may include the destination address, the network identifier, and the blockchain currency amount. The data element, or an alternate data element reserved for private use, may include the digital signature and transaction identifier or other identifier. In some instances, the transaction message may include a data element configured to store a transaction amount, which may include a zero amount, indicating that the transaction is not for fiat currency, and is instead a blockchain transaction. In some cases, a separate data element may indicate the transaction as a blockchain or non-fiat currency transaction. 
     The issuer  112  may include a transmitting unit  306  configured to transmit data over one or more networks via one or more network protocols. The transmitting unit  206  may submit the generated transaction message to the processing server  110  for processing the blockchain transaction using the methods and systems discussed herein. In some instances, the receiving unit  302  may receive a modified transaction message from the processing server  110 . For example, the processing server  110  may perform a risk assessment and may modify the transaction message to include an identified risk value and/or an authorization determination based thereon. The processing unit  304  may then approve or deny the transaction based on the data included in the modified transaction message using methods or systems that will be apparent to persons having skill in the relevant art. The processing unit  304  may generate an authorization response, which may be submitted, by the transmitting unit  306 , to the processing server  110  and processed accordingly. For instance, if the authorization response indicates approval, the processing server  110  may initiate the blockchain transaction at the blockchain network  106  and inform the payee  104  of the transaction approval. 
     The issuer  112  may also include a memory  316 . The memory  316  may be configured to store data suitable for use by the issuer  112  in performing the functions disclosed herein. For example, the memory  316  may be configured to store rules or algorithms for authorizing transactions, for converting fiat currency to/from blockchain currency, for generating blockchain addresses, for generating digital signatures, etc. Additional data that may be stored in the issuer  112  will be apparent to persons having skill in the relevant art. 
     Process for Authorizing a Blockchain Transaction in a Payment Network 
       FIG. 4  illustrates a process  400  for the authorization of a blockchain transaction in a traditional payment network using the system  100 . 
     In step  402 , the processing server  110  of the payment network  108  may generate a transaction message for a blockchain transaction. As discussed above, the transaction message may be formatted based on one or more standards and include a plurality of data elements, including at least a first data element configured to store a transaction amount and a second data element reserved for private use. The first data element may store a zero amount and the second data element may store a blockchain network identifier, a transaction amount of blockchain currency, and an address identifier associated with a payee  104 . 
     In step  404 , the transmitting unit  206  of the processing server  110  may transmit the transaction message to the issuer  112  via the payment network  108 . The receiving unit  302  of the issuer  112  may receive the transaction message using associated protocols, and, in step  406 , the processing unit  304  of the issuer  112  may check for authorization of the blockchain transaction. Authorization may be based on, for example, sufficient funding of the payer  102 , such as based on a stored currency amount, based on a blockchain currency amount associated with a transaction identifier associated with the payer  102 , etc., or other criteria that will be apparent to persons having skill in the relevant art. The processing unit  304  may generate an authorization response based on the determination, such as an authorization response that indicates approval or denial of the transaction. 
     In step  408 , the transmitting unit  306  of the issuer may transmit the authorization response message to the processing server  110  via the payment network  108 . The receiving unit  202  of the processing server  110  may receive the authorization response, which may be a transaction message formatted based on the one or more standards and transmitted using associated protocols, and, in step  410 , the processing unit  204  of the processing server  110  may evaluate the response code. Evaluation of the response code may include, for example, checking for approval or denial, checking for a reference identifier (e.g., referring to a corresponding blockchain transaction, such as a transaction identifier), verifying transaction details, etc. 
     In step  412 , the transmitting unit  206  of the processing server  110  may forward the response message on to the acquirer  114  via the payment network  108  and protocols associated with the transmission of transaction messages. In step  414 , the issuer  112  may conduct the blockchain transaction, such as by submitting, using the transmitting unit  306 , a transaction request to the appropriate blockchain network  106  using the details included in the data element reserved for private use in the received transaction message. In some instances, the issuer  112  may receive a transaction identifier from the blockchain network  106 , and the processing unit  304  may include the transaction identifier in the authorization response message provided to the processing server  110 , such as in a data element configured to store a reference identifier. In such instances, step  414  may be performed prior to steps  408  through  412 . In step  416 , the acquirer  114  may verify that the blockchain transaction has occurred, such as by verifying the receipt of blockchain currency, validating the transaction using the transaction identifier, etc. 
     Processing of a Blockchain-Based Transaction Message 
       FIG. 5  illustrates the processing of a transaction message associated with a blockchain transaction in the processing server  110  of the payment network  108 . 
     In step  502 , the receiving unit  202  of the processing server  110  may receive a transaction request, such as from the payer  102  or an issuer  112 . The transaction request may include at least a network identifier associated with a blockchain network  106 , a transaction amount for a blockchain currency associated with the blockchain network  106 , and a public key and/or an address identifier associated with a payee  104 . In some embodiments, the transaction request may also include a transaction identifier and digital signature associated with a private key associated with the payer  102 . In other embodiments, the transaction request may include an account identifier, such as in instances where the processing server  110  may store a private key associated with the payer  102 , such as in an account profile  210  in the account database  208 . 
     In step  504 , the processing unit  204  of the processing server  110  may determine if the received transaction request includes an address identifier. If the transaction request does not include an address identifier, and, for instance, includes a public key associated with the payee  104 , then, in step  506 , the processing unit  204  may generate an address identifier for the payee  104 . In some instances, step  506  may include transmitting, by the transmitting unit  206  of the processing server, the generated address identifier to the payee  104 . 
     Once the address identifier has been generated and/or identified, then, in step  508 , the processing unit  204  may determine if the network identifier included in the received transaction request is encoded. If the network identifier is not encoded, then, in step  510 , the processing unit  204  may encode the network identifier. The network identifier may be encoded by applying the network identifier included in the received transaction request to one or more algorithms configured to generate an encoded value, such as a hexadecimal value. 
     Once the network identifier is encoded, in step  512 , the processing unit  204  may generate a transaction message. The transaction message may be formatted based on one or more standards associated with transaction messages, such as the ISO 8583 standard. The transaction message may include a plurality of data elements. For instance, data elements may include a data element configured to store a transaction amount, which may include a zero amount or other value indicative of a blockchain transaction, a data element configured to store a personal account number, which may include an account identifier associated with the payer  102 , a data element configured to store a merchant identifier, which may include an account identifier associated with the payee  104  (e.g., which may be the address identifier), and a data element reserved for private use. The data element reserved for private use may include at least the encoded network identifier, the address identifier, and the transaction amount of blockchain currency. In some embodiments, the data element reserved for private use, or an additional data element reserved for private use, may also include payer information, such as a transaction identifier and digital signature associated with the payer  102  to verify a source of the blockchain currency used to fund the transaction. In some instances, the transaction message may also include a message type indicator, which may be indicative of an authorization message. 
     In step  514 , the transmitting unit  206  of the processing server  110  may transmit the transaction message to the issuer  112  associated with the payer  102  via the payment network  108 . The issuer  112  may then authorize and conduct the blockchain transaction using the data included in the transaction message. In some embodiments, the process  500  may further include receiving, by the receiving unit  202 , an authorization response from the issuer  112  and processing, by the processing unit  204 , the transaction accordingly. For example, if the authorization response indicates approval of the transaction, the processing unit  204  of the processing server  110  may initiate a blockchain transaction with the blockchain network  106  using the associated transaction information. 
     Blockchain Transaction Invoice 
       FIG. 6  illustrates a process  600  for the generation of an invoice for a blockchain transaction. An invoice may be a data value, container, element, or other data storage type that may include data suitable for use in the initiation and processing of a blockchain transaction. The invoice, as discussed herein, may be stored in a data element of a transaction message, such as a data element reserved for private use based on one or more standards, such as the ISO 8583 standard. 
     As illustrated in  FIG. 6 , an invoice may be comprised of a network identifier  602 , a payee public key  604 , and a transaction value  606 . The network identifier  602  may be associated with a blockchain network  106  used to process blockchain transactions of the respective blockchain currency. The network identifier  602  may be, for example, a unique value associated with the blockchain network  106 , such as an alphanumeric name, a numerical value, an internet protocol address, a media access control address, etc. The payee public key  604  may be a public key of a key pair associated with a payee  104  to whom blockchain currency is to be transferred as a result of the blockchain transaction. The transaction value  606  may be a transaction amount of blockchain currency that is to be transferred as a result of the blockchain transaction. 
     The network identifier  602  may be encoded via the use of one or more encoding algorithms  608  to obtain an encoded network value  612 . The encoded network value  612  may be a hexadecimal value associated with the blockchain network  106 . The encoded network value  612  may be used, for instance, in the identification of the blockchain network  106  to be used to conduct the blockchain transaction. In some instances, the encoded network value  612  may be comprised of data used in the communication of a transaction request to the blockchain network  106 , such as a destination address (e.g., an internet protocol address), or information usable by a processing device (e.g., of the processing server  110  or issuer  112 ) in the identification of a destination address for the blockchain network  106 , such as by using a lookup table. 
     The payee public key  604  may be used to generate a payee address  614  via the use of one or more hashing algorithms  610 . The payee address  614  may be a unique value associated with the payee  104  and may be used as a destination address for currency being transferred in a subsequent blockchain transaction. The hashing algorithms  610  may, in some embodiments, additionally and/or alternatively use encoding, such as Base 58 Check encoding, to generate a payee address  614  that is a string of alphanumeric characters that consists of only characters that are easily distinguished. 
     The encoded network value  612 , payee address  614 , and transaction value  606  may be combined (e.g., in a string of characters, in an array of values, or other suitable type of data storage) in a transaction message data element  616 . The data element  616  may be, for example, a data element reserved for private use in the one or more standards on which transaction messages are based, such as the ISO 8583 standard. The invoice may be included in the data element  616 , which may be included in a transaction message and used to initiate a blockchain transaction to be carried out by the blockchain network  106  associated with the network identifier  602 , to pay the transaction value  606  to a payee  104  associated with the generated payee address  614 . 
     Process for Linking Blockchain Transactions to Verified Identities 
       FIG. 7  illustrates a process  700  for the linking of blockchain transactions to privately verified identities using the processing server  110  of the payment network  108 . It will be apparent to persons having skill in the relevant art that the process  700  illustrated in  FIG. 7  and discussed herein may be performed by any entity configured to receive and analyze transaction messages and receiving and verify blockchain transactions using privately and/or publicly available sources of blockchain transaction information (e.g., by analysis of the blockchain itself), such as the issuer  112 . For example, the steps of the process  700  as performed by the components of the processing server  110 , as discussed below, may be performed by corresponding components of the issuer  112  in performing the process  700  by the issuer  112 . 
     In step  702 , the receiving unit  202  of the processing server  110  may receive a transaction message. The transaction message may be formatted based on one or more standards, such as the ISO 8583 standard, and may include a plurality of data elements. The data elements may include at least a first data element configured to store a personal account number, a second data element configured to store a merchant identifier, and a third data element configured to store at least a blockchain network identifier associated with a blockchain network  106 . In some embodiments, the data included in each of the data elements may be included in a single data element, such as a data element reserved for private use. 
     In step  704 , the processing unit  204  of the processing server  110  may identify account profiles  210  stored in the account database  208  that correspond to entities involved in the associated payment transaction. For example, the processing server  110  may identify a first account profile associated with a payer  102  that includes an account identifier included in the first data element configured to store a personal account number, and may identify a second account profile associated with a payee  104  that includes an account identifier included in the second data element configured to store a merchant identifier. In some instances, the account identifiers may be address identifiers, such as generated using public keys of a key pair associated with the respective entity. 
     In step  706 , the processing unit  204  may determine if a fraud score for the corresponding payment transaction is requested. For instance, a fraud score may be requested by an issuer  112  associated with the payer  102  or an acquirer  114  associated with the payee  104 , such as in instances where the transaction message is received by the processing server  110  prior to processing of the corresponding blockchain transaction. If a fraud score is not requested, the process  700  may proceed to step  712 . If a fraud score is requested, then, in step  708 , the processing unit  204  may apply fraud rules (e.g., as stored in the memory  216 ) to data included in the received transaction message, and, in some instances, the identified account profiles, to generate a fraud score. In step  710 , the transmitting unit  206  of the processing server  110  may transmit the fraud score to the appropriate entity, such as the issuer  112  and/or the acquirer  114 . 
     In step  712 , the processing unit  204  may determine if a blockchain transaction associated with the received transaction message occurred. The determination may either be: (1) based on the receipt of a transaction notification from the blockchain network  106  or from an entity configured to initiate the blockchain transaction (e.g., the issuer  112 ); (2) inherent to the processing server  110  in instances where the processing server  110  initiates the blockchain transaction; or (3) based on verification of the blockchain transaction by analysis of the blockchain itself (e.g., using the payee address, transaction amount, and other information included in the transaction message). If the blockchain transaction did not occur, then the process  700  may be completed, as no linkage may be necessary. 
     If the blockchain transaction did occur, then, in step  714 , the receiving unit  202  of the processing server  110  may receive a transaction notification associated with the blockchain transaction. The transaction notification may be provided by, for example, the blockchain network  106 , the issuer  112 , the acquirer  114 , the payer  102 , the payee  104 , or an entity configured to verify blockchain transactions using the blockchain, such as the payment network  108  (e.g., using the processing unit  204 ) or a third party. The transaction notification may include at least a transaction identifier and an address identifier. The transaction identifier may be a unique value associated with the blockchain transaction. The address identifier may include an address associated with the payee  104 . In some instances, the transaction notification may also include a payer address associated with the payer  102 , and any additional information, such as a transaction amount. In some cases, the processing unit  204  may identify such information from the received transaction message. 
     In step  716 , the processing unit  204  may identify any applicable linkages based on the information included in the received transaction notification. For instance, the processing unit  204  may identify a linkage between the blockchain transaction and the second account profile identified in step  704  associated with the payee  104  of the transaction based on a correspondence with the included account and/or address identifier and the address identifier included in the received transaction notification. In instances where the transaction notification may include a payer address, the processing unit  204  may identify a linkage between the first account profile identified in step  704  and the blockchain transaction using the payer address. 
     In step  718 , the processing unit  204  may storage linkage data in the processing server  110 . For example, the linkage data may be stored as a linkage between each applicable account profile and the transaction identifier in the memory  216 , may be stored in a transaction data entry  214  in the transaction database  212  associated with the blockchain transaction (e.g., as account identifiers for linked account profiles  210 ), or may be stored in account profiles  210  that are identified as linked to the transaction, such as by storage of the transaction identifier for the linked transaction in the account profile  210 . In some instances, storage of linkage data may include transmitting, by the transmitting unit  206 , linkage data to an external entity for storage, such as to the issuer  112  for storage in an account profile  314  for use in future blockchain transactions. 
     Process for Management of Fractional Reserves 
       FIG. 8  illustrates a process  800  for the management of fractional reserves of fiat and blockchain currency in an issuer  112  or other financial institution configured to issue transaction accounts using a combination of fiat and one or more blockchain currencies. 
     In step  802 , the receiving unit  302  of the issuer  112  may receive a transaction message. The transaction message may be associated with a payment transaction and may be formatted based on one or more standards, such as the ISO 8583, and received using associated communication protocols. The transaction message may include a plurality of data elements, including at least a data element reserved for private use that includes at least a specific address associated with an entity involved in the related transaction and a transaction amount. In some instances, the data element reserved for private use, or another data element in addition thereto, may include additional addresses. 
     In step  804 , the processing unit  304  of the issuer  112  may identify account profiles  314  stored in the account database  312  involved in the related payment transaction. The account profiles  314  may be identified based on addresses included therein that correspond to addresses included in data elements included in the received transaction message. In instances where multiple involved account profiles  314  may be identified, the remaining steps of the process  800  may be performed for each of the identified account profiles  314 . 
     In step  806 , the processing unit  304  may identify if the identified account profile  314  corresponds to a payer  102  or payee  104  for the transaction. The determination may be based on the data element in which the associated address is stored, a location within the data element (e.g., in the invoice stored therein), a source of the transaction message, or other suitable value. 
     If the account profile  314  is associated with a payee  104  for the transaction, then, in step  808 , the processing unit  304  may determine if fiat currency is involved in the transaction. The determination may be based on data elements included in the received transaction message. For example, if fiat currency is involved, each data element included in the transaction message may include data as specified based on the one or more standards, including a transaction amount having a non-zero value. In another example, if fiat currency is not involved, a data element configured to store a transaction amount may have a zero amount, a data element reserved for private use may include a blockchain transaction invoice, and/or an additional data element may include data indicating that the transaction is a blockchain or otherwise non-fiat transaction. 
     If the transaction involves the use of fiat currency, then, in step  810 , the processing unit  304  may add fiat currency to a fiat currency amount in the corresponding account profile  314 . The currency amount added may be based on an amount included in a data element configured to store a transaction amount in the received transaction message. In step  812 , a fiat currency amount in a central account  310  associated with the fiat currency stored in the central database  308  may be updated (e.g., increased) by the same or a related (e.g., due to a fee) currency amount. 
     If the transaction does not involve the use of a fiat currency, then, in step  814 , the processing unit  304  may add blockchain currency to a blockchain currency amount in the corresponding account profile  314 . The currency amount added may be based on an amount included in a data element reserved for private use in the received transaction message, or as included in a transaction notification associated with the corresponding blockchain transaction, such as via analysis of the blockchain. In step  816 , a blockchain currency amount in a central account  310  associated with the blockchain currency may be updated (e.g., increased) by the same or a related (e.g., due to a fee) currency amount. 
     If, in step  806 , the processing unit  304  determines that the involved account profile  314  corresponds to a payer  102  for the transaction, then, in step  818 , the processing unit  304  may determine if fiat currency is involved in the transaction. Similar to the determination made in step  808  for a payee  104 , the determination may be based on data elements included in the received transaction message. If the transaction involves fiat currency, then, in step  820 , fiat currency may be deducted from the account profile  314  based on a currency amount. In step  822 , fiat currency may be deducted from the fiat currency central account  310  of the central database  308 , based on a currency amount (e.g., with an additional fee removed). If the transaction involves blockchain currency, then the account profile  314  and a blockchain currency central account  310  may both be updated via deductions of blockchain currency based on a currency amount. 
     Process for Authorization of Blockchain-Based Transactions Based on Risk 
       FIG. 9  illustrates a process  900  for the authorization of blockchain transactions based on risk using the processing server  110  of the payment network  108 . It will be apparent to persons having skill in the relevant art that the process  900  illustrated in  FIG. 9  and discussed herein may be performed by any entity configured to receive and analyze transaction messages and determine risk, such as the issuer  112 . For example, the steps of the process  900  as performed by the components of the processing server  110 , as discussed below, may be performed by corresponding components of the issuer  112  in performing the process  900  by the issuer  112 . 
     In step  902 , the receiving unit  202  of the processing server  110  may receive a transaction message. The transaction message may be formatted based on one or more standards, such as the ISO 8583 standard, and may include a plurality of data elements. The data elements may include a first data element configured to store a personal account number that includes a specific account identifier and a second data element reserved for private use that includes at least a blockchain network identifier and a transaction amount. In step  904 , the processing unit  204  of the processing server  110  may identify an account profile  210  associated with a payer  102  involved in the payment transaction. The account profile  210  may be identified based on a correspondence between the included account identifier and the specific account identifier included in the data element configured to store a personal account number. 
     In step  906 , the processing unit  204  may determine if the identified account profile  210  includes sufficient blockchain currency to fund the blockchain transaction. If the account includes sufficient currency, then, in step  908 , a risk value for the transaction may be determined based on the sufficiency of currency. In some instances, the risk value may be based on a difference in the available currency (e.g., as indicated in the account profile  210 ) and the transaction amount. For example, there may be a higher risk indicated if the transaction is barely covered such that a concurrent transaction could result in the payer  102  being unable to afford the amount. 
     If, in step  906 , the processing unit  204  determines that there is not sufficient blockchain currency in the account profile  210 , then, in step  910 , the processing unit  204  may calculate an equivalent amount of fiat currency. The calculation may use one or more conversion rates, such as may be stored in the memory  216 , or retrieved via use of the transmitting unit  206  and receiving unit  202 , such as by requesting a conversion rate from the blockchain network  106 , a financial institution, or other third party. In step  912 , the processing unit  204  may determine if the identified account profile  210  includes a sufficient amount of fiat currency to cover the equivalent amount for the transaction. 
     If the processing unit  204  determines that the account does not include a sufficient amount of blockchain or fiat currency, then, in step  914 , the processing unit  204  may decline the payment transaction due to insufficient funds. The decline of the payment transaction may include modifying the transaction message to indicate that the transaction is declined, such as by modification of a message type indicator and/or one or more data elements. In step  916 , the transmitting unit  206  may transmit the modified transaction message as an authorization response to the received transaction message. 
     If the processing unit  204  determines, in step  912 , that there is sufficient fiat currency to cover the transaction amount, then the process  900  may proceed to step  908  where a risk value is determined. In some instances, the risk value may be affected by the availability of each specific type of currency. For instance, if the payer  102  has insufficient blockchain currency, but a sufficient equivalent amount of fiat currency, the risk value may indicate a higher risk than a sufficient amount of blockchain currency in the same proportion. Risk values based on availability of blockchain and fiat currency may be similar to risk values based on availability of multiple types of currency in traditional transactions where multiple fiat currencies may be involved. 
     In step  918 , the processing unit  204  may determine if the risk value that is determined is an acceptable level. The acceptance of a risk value may be based on criteria set forth by the issuer  112  associated with the payer  102 , by the payer  102 , by the payment network  108 , by a payee  104  involved in the transaction, by an acquirer  114  associated with the payee  104 , or by a combination thereof. If the risk value is not acceptable, then, in step  920 , the processing unit  204  may decline the payment transaction due to the high risk. The declining of the transaction may include modifying the transaction message to indicate that the transaction is declined, such as by modification of a message type indicator and/or one or more data elements. In some instances, the modification may include an indication of the reason for denial, such as, in this case, the high risk. In step  924 , the transmitting unit  206  may transmit the modified transaction message as an authorization response to the received transaction message via the payment network  108 . 
     If, in step  918 , the processing unit  204  determines that the risk value is acceptable, then, in step  922 , the transaction may be authorized. Authorization of the transaction may include modifying the transaction message to indicate approval of the transaction, such as by modification of a message type indicator and/or one or more data elements. In step  924 , the modified transaction message may be transmitted via the payment network  108 . In some instances, a transaction message for a denied transaction may be transmitted to the payer  102  and/or payee  104 , while a transaction message for an approved transaction may be transmitted to the issuer  112  or other entity for further authorization. 
     Exemplary Method for Authorizing a Blockchain-Based Transaction 
       FIG. 10  illustrates a method  1000  for authorizing a blockchain-based transaction using a transaction message generated by and transmitted via a payment network  108 . 
     In step  1002 , a transaction request may be received by a receiving device (e.g., the receiving unit  202 ), wherein the transaction request includes at least a network identifier associated with a blockchain network (e.g., the blockchain network  106 ), a transaction amount, and one of: a public key and an address identifier. In step  1004 , an address identifier may be generated by a processing device (e.g., the processing unit  204 ) using at least the public key included in the received transaction request and one or more hashing and/or encoding algorithms if the received transaction request does not include an address identifier. In one embodiment, the one or more hashing and/or encoding algorithms includes the use of Base 58 Check encoding. 
     In step  1006 , a transaction message may be generated by the processing device, wherein the transaction message is formatted based on one or more standards and includes a plurality of data elements, including at least a first data element configured to store a transaction amount and a second data element reserved for private use, and the first data element includes a zero value and the second data element includes at least (i) the network identifier or an encoded value based on the network identifier, (ii) the address identifier, and (iii) the transaction amount. In one embodiment, the one or more standards may include at least the ISO 8583 standard. In some embodiments, the transaction message may include a message type indicator indicative of an authorization message. In one embodiment, the encoded value based on the network identifier is a hexadecimal value generated using at least the network identifier and one or more algorithms. In some embodiments, the transaction message may include a third data element configured to store a processing code indicative of a non-currency transaction. 
     In step  1008 , the transaction message may be transmitted by a transmitting device (e.g., the transmitting unit  206 ) to a financial institution (e.g., the issuer  112 ) using a payment network (e.g., the payment network  108 ). In one embodiment, the method  1000  may further include receiving, by the receiving device  202 , a return transaction message from the financial institution  112  using the payment network  108 , wherein the return transaction message includes a third data element configured to store a response code. In a further embodiment, the method  1000  may even further include transmitting, by the transmitting device  206 , the return transaction message in response to the received transaction request. In another further embodiment, the response code may be indicative of approval of the transaction associated with the generated transaction message, and the second data element may further include a reference identifier. In an even further embodiment, the reference identifier may be at least one of: a value associated with a transaction conducted using the associated blockchain network  106  and a digital signature generated based on at least a portion of the data included in the second data element included in the generated transaction message. 
     Exemplary Method for Linking Blockchain Transactions to Private Verified Identities 
       FIG. 11  illustrates a method  1100  for the linking of blockchain transactions to privately verified identities based on the use of standardized transaction messages and data elements included therein. 
     In step  1102 , a plurality of account profiles (e.g., account profiles  210 ) may be stored in an account database (e.g., the account database  208 ), wherein each account profile  210  includes data related to a transaction account including at least an account identifier and account data. In one embodiment, the account data may include at least one of: transaction data, location data, characteristic data, and fraud data. 
     In step  1104 , a transaction message may be received by a receiving device (e.g., the receiving unit  202 ), wherein the transaction message is formatted based on one or more standards and includes a plurality of data elements including at least a first data element configured to store a personal account number, a second data element configured to store a merchant identifier, and a third data element configured to store a blockchain network identifier. In one embodiment, the transaction message may include a fourth data element configured to store a processing code indicative of a non-currency transaction. In some embodiments, the transaction message may include a message type indicator indicative of an authorization message. 
     In step  1106 , a first account profile  210  stored in the account database  208  may be identified by a processing device (e.g., the processing unit  204 ) where the included account identifier corresponds to the personal account number stored in the first data element included in the received transaction message. In step  1108 , a second account profile  210  stored in the account database  208  may be identified by the processing device  204  where the included account identifier corresponds to the merchant identifier stored in the second data element included in the received transaction message. 
     In step  1110 , a transaction notification may be received by the receiving device  202 , wherein the transaction notification indicates a transaction processed using a blockchain network (e.g., the blockchain network  106 ) associated with the blockchain network identifier stored in the third data element included in the received transaction message and includes at least a transaction identifier and an address identifier associated with one of the first account profile  210  and the second account profile  210 . In one embodiment, the address identifier may be a hash generated using a public key associated with one of the first account profile  210  and the second account profile  210 . 
     In step  1112 , a linkage between the transaction identifier included in the received transaction notification and at least one of: the address identifier, the personal account number, and the merchant identifier may be stored by the processing device  204 . In one embodiment, the linkage may be stored in a transaction database (e.g., the transaction database  212 ), as a linkage profile, the linkage profile including at least the transaction identifier and the at least one of: the address identifier, the personal account number, and the merchant identifier. In some embodiments, the linkage may be stored in the first account profile  210 . In one embodiment, the linkage may be stored in the second account profile  210 . 
     Exemplary Method for Managing Fractional Reserves of Blockchain Currency 
       FIG. 12  illustrates a method  1200  for the management of fractional reserves of blockchain and fiat currency for use by a financial institution in a payment network. 
     In step  1202 , at least a fiat amount associated with a fiat currency may be stored in a first central account (e.g., central account  310 ). In step  1204 , at least a blockchain amount associated with a blockchain currency may be stored in a second central account  310 . In step  1206 , a plurality of account profiles (e.g., account profiles  314 ) may be stored in an account database (e.g., the account database  312 ), wherein each account profile  314  may include data associated with a consumer (e.g., the payer  102 , payee  104 , a transaction account, etc.) including at least a fiat currency amount, a blockchain currency amount, an account identifier, and an address. In one embodiment, the blockchain amount stored in the second central account  310  is based on a sum of the blockchain currency amounts included in each account profile  314  stored in the account database  312 . 
     In step  1208 , a transaction message associated with a payment transaction may be received by a receiving device (e.g., the receiving unit  302 ), wherein the transaction message is formatted based on one or more standards and includes a plurality of data elements, including at least a data element reserved for private use including a specific address and a transaction amount. In one embodiment, the one or more standards may include at least the ISO 8583 standard. In step  1210 , a specific account profile  314  stored in the account database  312  may be identified by a processing device (e.g., the processing unit  304 ) where the included address corresponds to the specific address included in the data element in the received transaction message. 
     In step  1212 , the blockchain currency amount included in the identified specific account profile  314  may be updated by the processing device  304  based on the transaction amount included in the data element in the received transaction message. In one embodiment, the method  1200  may further include updating, by the processing device  304 , the blockchain amount stored in the second central account  310  based on the transaction amount included in the data element in the received transaction amount. In some embodiments, the method  1200  may also include initiating, by the processing device  304 , a blockchain transaction using a blockchain network (e.g., the blockchain network  106 ) associated with the blockchain currency amount, wherein the blockchain transaction is for the transaction amount to or from the specific address. 
     In one embodiment, the second central account  310  is further configured to store a plurality of keys, each key associated with an account profile  314  stored in the account database  312 . In a further embodiment, the method  1200  may further include generating, by the processing device  304 , the address stored in each account profile  314  of the account database  312  based on application of the associated key to one or more hashing and/or encoding algorithms. In an even further embodiment, the one or more hashing and/or encoding algorithms may include the use of Base 58 Check encoding. 
     In one embodiment, the transaction message may further include a data element configured to store a personal account number that includes a funding address. In a further embodiment, the method  1200  may also include: identifying, by the processing device  304 , a funding account profile  314  stored in the account database  312  where the included address corresponds to the funding address; and deducting, by the processing device  304 , the blockchain currency amount included in the identified funding account profile  314  based on the transaction amount included in the data element in the received transaction message, wherein updating the blockchain currency amount included in the identified specific account profile  314  includes adding to the blockchain currency amount based on the transaction amount included in the data element in the received transaction message. 
     Exemplary Method for Authorizing a Blockchain Transaction Using Risk Values 
       FIG. 13  illustrates a method  1100  for the authorization of blockchain transactions in a payment network using risk values based on available blockchain and/or fiat currency. 
     In step  1302 , a plurality of account profiles (e.g., account profiles  210 ) may be stored in an account database (e.g., the account database  208 ), wherein each account profile  210  includes data related to a consumer (e.g., the payer  102 , payee  104 , a transaction account, etc.) including at least an account identifier, a fiat currency amount, and one or more blockchain currency amounts, each blockchain currency amount being associated with a blockchain network (e.g., the blockchain network  106 ). 
     In step  1304 , a transaction message for a payment transaction may be received by a receiving device (e.g., the receiving unit  202 ), wherein the transaction message is formatted based on one or more standards and includes a plurality of data elements, including a first data element configured to store a personal account number that includes a specific account identifier and a second data element reserved for private use that includes at least a network identifier and a transaction amount. In one embodiment, the one or more standards may include at least the ISO 8583 standard. 
     In step  1306 , a specific account profile  210  stored in the account database  208  may be identified by a processing device (e.g., the processing unit  204 ) where the included account identifier corresponds to the specific account identifier included in the first data element of the received transaction message. In step  1308 , a risk value may be identified by the processing device  204  for the payment transaction, wherein the risk value is based on at least the transaction amount included in the second data element of the received transaction message and at least one of: the fiat currency amount and a blockchain currency amount associated with a blockchain network  106  corresponding to the network identifier included in the second data element of the received transaction message included in the identified specific account profile  210 . 
     In one embodiment, the transaction amount may be an amount of blockchain currency and identifying a risk value for the payment transaction may be based on the transaction amount included in the second data element of the received transaction message and the blockchain currency amount associated with a blockchain network  106  corresponding to the network identifier included in the second data element of the received transaction message included in the identified specific account profile. In some embodiments, the transaction amount may be an amount of blockchain currency and identifying a risk value for the payment transaction may be based on the transaction amount included in the second data element of the received transaction message, the fiat currency amount included in the identified specific account profile, and an exchange rate for exchange of blockchain currency to and/or from fiat currency. 
     In step  1310 , authorization of the payment transaction may be determined by the processing device  204  based on at least the identified risk value. In step  1312 , the received transaction message may be modified by the processing device  204  based on the authorization determination. In one embodiment, modifying the received transaction message may include storing, in a third data element of the transaction message, a response code indicative of the authorization determination. In step  1314 , a transmitting device (e.g., the transmitting unit  206 ) may transmit the modified transaction message. 
     In one embodiment, the method  1300  may further include: generating, by the processing device  204 , an address identifier for each account profile  210  using at least the account identifier included in the respective account profile  210  and one or more hashing and/or encoding algorithms. In a further embodiment, the specific account identifier may have a value equivalent to the address identifier generated using the account identifier included in the identified specific account profile  210 . In another further embodiment, the one or more hashing and/or encoding algorithms may include the use of Base 58 Check encoding. 
     In some embodiments, the method  1300  may also include initiating, by the processing device  204 , a blockchain transaction using the blockchain network  106  corresponding to the network identifier included in the second data element of the received transaction message for the transaction amount from the specific account identifier. In a further embodiment, modifying the received transaction message may further include adding, to the second data element, a reference identifier generated as a result of initiating the blockchain transaction. 
     Computer System Architecture 
       FIG. 14  illustrates a computer system  1400  in which embodiments of the present disclosure, or portions thereof, may be implemented as computer-readable code. For example, the processing server  110  and issuer  112  of  FIG. 1  may be implemented in the computer system  1400  using hardware, software, firmware, non-transitory computer readable media having instructions stored thereon, or a combination thereof and may be implemented in one or more computer systems or other processing systems. Hardware, software, or any combination thereof may embody modules and components used to implement the methods of  FIGS. 4, 5, and 7-13 . 
     If programmable logic is used, such logic may execute on a commercially available processing platform or a special purpose device. A person having ordinary skill in the art may appreciate that embodiments of the disclosed subject matter can be practiced with various computer system configurations, including multi-core multiprocessor systems, minicomputers, mainframe computers, computers linked or clustered with distributed functions, as well as pervasive or miniature computers that may be embedded into virtually any device. For instance, at least one processor device and a memory may be used to implement the above described embodiments. 
     A processor unit or device as discussed herein may be a single processor, a plurality of processors, or combinations thereof. Processor devices may have one or more processor “cores.” The terms “computer program medium,” “non-transitory computer readable medium,” and “computer usable medium” as discussed herein are used to generally refer to tangible media such as a removable storage unit  1418 , a removable storage unit  1422 , and a hard disk installed in hard disk drive  1412 . 
     Various embodiments of the present disclosure are described in terms of this example computer system  1400 . After reading this description, it will become apparent to a person skilled in the relevant art how to implement the present disclosure using other computer systems and/or computer architectures. Although operations may be described as a sequential process, some of the operations may in fact be performed in parallel, concurrently, and/or in a distributed environment, and with program code stored locally or remotely for access by single or multi-processor machines. In addition, in some embodiments the order of operations may be rearranged without departing from the spirit of the disclosed subject matter. 
     Processor device  1404  may be a special purpose or a general purpose processor device. The processor device  1404  may be connected to a communications infrastructure  1406 , such as a bus, message queue, network, multi-core message-passing scheme, etc. The network may be any network suitable for performing the functions as disclosed herein and may include a local area network (LAN), a wide area network (WAN), a wireless network (e.g., WiFi), a mobile communication network, a satellite network, the Internet, fiber optic, coaxial cable, infrared, radio frequency (RF), or any combination thereof. Other suitable network types and configurations will be apparent to persons having skill in the relevant art. The computer system  1400  may also include a main memory  1408  (e.g., random access memory, read-only memory, etc.), and may also include a secondary memory  1410 . The secondary memory  1410  may include the hard disk drive  1412  and a removable storage drive  1414 , such as a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, etc. 
     The removable storage drive  1414  may read from and/or write to the removable storage unit  1418  in a well-known manner. The removable storage unit  1418  may include a removable storage media that may be read by and written to by the removable storage drive  1414 . For example, if the removable storage drive  1414  is a floppy disk drive or universal serial bus port, the removable storage unit  1418  may be a floppy disk or portable flash drive, respectively. In one embodiment, the removable storage unit  1418  may be non-transitory computer readable recording media. 
     In some embodiments, the secondary memory  1410  may include alternative means for allowing computer programs or other instructions to be loaded into the computer system  1400 , for example, the removable storage unit  1422  and an interface  1420 . Examples of such means may include a program cartridge and cartridge interface (e.g., as found in video game systems), a removable memory chip (e.g., EEPROM, PROM, etc.) and associated socket, and other removable storage units  1422  and interfaces  1420  as will be apparent to persons having skill in the relevant art. 
     Data stored in the computer system  1400  (e.g., in the main memory  1408  and/or the secondary memory  1410 ) may be stored on any type of suitable computer readable media, such as optical storage (e.g., a compact disc, digital versatile disc, Blu-ray disc, etc.) or magnetic tape storage (e.g., a hard disk drive). The data may be configured in any type of suitable database configuration, such as a relational database, a structured query language (SQL) database, a distributed database, an object database, a distributed key-value store, etc. Suitable configurations and storage types will be apparent to persons having skill in the relevant art. 
     The computer system  1400  may also include a communications interface  1424 . The communications interface  1424  may be configured to allow software and data to be transferred between the computer system  1400  and external devices. Exemplary communications interfaces  1424  may include a modem, a network interface (e.g., an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via the communications interface  1424  may be in the form of signals, which may be electronic, electromagnetic, optical, or other signals as will be apparent to persons having skill in the relevant art. The signals may travel via a communications path  1426 , which may be configured to carry the signals and may be implemented using wire, cable, fiber optics, a phone line, a cellular phone link, a radio frequency link, etc. 
     The computer system  1400  may further include a display interface  1402 . The display interface  1402  may be configured to allow data to be transferred between the computer system  1400  and external display  1430 . Exemplary display interfaces  1402  may include high-definition multimedia interface (HDMI), digital visual interface (DVI), video graphics array (VGA), etc. The display  1430  may be any suitable type of display for displaying data transmitted via the display interface  1402  of the computer system  1400 , including a cathode ray tube (CRT) display, liquid crystal display (LCD), light-emitting diode (LED) display, capacitive touch display, thin-film transistor (TFT) display, etc. 
     Computer program medium and computer usable medium may refer to memories, such as the main memory  1408  and secondary memory  1410 , which may be memory semiconductors (e.g., DRAMs, etc.). These computer program products may be means for providing software to the computer system  1400 . Computer programs (e.g., computer control logic) may be stored in the main memory  1408  and/or the secondary memory  1410 . Computer programs may also be received via the communications interface  1424 . Such computer programs, when executed, may enable computer system  1400  to implement the present methods as discussed herein. In particular, the computer programs, when executed, may enable processor device  1404  to implement the methods illustrated by  FIGS. 4, 5, and 7-13 , as discussed herein. Accordingly, such computer programs may represent controllers of the computer system  1400 . Where the present disclosure is implemented using software, the software may be stored in a computer program product and loaded into the computer system  1400  using the removable storage drive  1414 , interface  1420 , and hard disk drive  1412 , or communications interface  1424 . 
     Techniques consistent with the present disclosure provide, among other features, systems and methods for authorizing blockchain transactions, identifying risk values in blockchain transactions, and linking blockchain transactions with verified identities. While various exemplary embodiments of the disclosed system and method have been described above it should be understood that they have been presented for purposes of example only, not limitations. It is not exhaustive and does not limit the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practicing of the disclosure, without departing from the breadth or scope.