# US 10,769,629 B2 · Method and system for linkage of blockchain-based assets to fiat currency accounts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,769,629 B2 - Document ID: US10769629B2 - Status: Granted - Kind: B2 - Application number: 16/023,497 - Filed: 2018-06-29 - Published: 2018-10-25 - Granted: 2020-09-08 - Earliest claimed: 2015-05-21 - Assignees: Mastercard International Incorporated - Applicants: Mastercard International Incorporated - Inventors: Steven Charles Davis - Web page: https://patentgrep.com/patent/US10769629B2 ## CPC - G06Q 20/3829: {involving key management} - G06Q 20/065: {using e-cash} - G06Q 20/0855: {involving a third party} - G06Q 20/10: specially adapted for electronic funds transfer [EFT] systems; specially adapted for home banking systems - G06Q 20/3678: {e-cash details, e.g. blinded, divisible or detecting double spending} - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - G06Q: INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for managing fractional reserves of blockchain currency includes: storing, in a first central account, a fiat amount associated with a fiat currency; storing, in a second central account, a blockchain amount associated with a blockchain currency; storing a plurality of account profiles, each profile including a fiat currency amount, blockchain currency amount, account identifier, and address; receiving a transaction message associated with a payment transaction, the message being formatted based on one or more standards and including a plurality of data elements, including a data element reserved for private use including a specific address and a transaction amount; identifying a specific account profile that includes the specific address included in the data element in the received transaction message; and updating the blockchain currency amount included in the identified specific account profile based on the transaction amount included in the data element in the received transaction message. ## Claims ### Claim 1 A method for managing fractional reserves of blockchain currency, comprising: receiving, by a receiving device, a transaction message associated with a payment transaction transmitted via payment rails associated with a payment network, wherein the transaction message is formatted based on a standard 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; identifying, by a processing device, a specific account profile stored in an account database that includes the specific address included in the data element in the received transaction message, wherein the specific account profile further includes a fiat currency amount and a blockchain currency amount; and updating, by the processing device, the blockchain currency amount included in the identified specific account profile based on the transaction amount included in the data element in the received transaction message. ### Claim 2 (depends on 1) The method of claim 1, further comprising: updating, by the processing device, the blockchain amount stored in a second central account based on the transaction amount included in the data element in the received transaction message. ### Claim 3 (depends on 1) The method of claim 1, wherein the blockchain amount stored in a second central account is based on a sum of the blockchain currency amounts included in each account profile stored in the account database. ### Claim 4 (depends on 1) The method of claim 1, further comprising: initiating, by the processing device, a blockchain transaction using a blockchain network associated with the blockchain currency amount, wherein the blockchain transaction is for the transaction amount to or from the specific address. ### Claim 5 (depends on 1) The method of claim 1, wherein the standard includes at least the ISO 8583 standard. ### Claim 6 (depends on 1) The method of claim 1, wherein a second central account is configured to store a plurality of keys, each key associated with an account profile stored in the account database. ### Claim 7 (depends on 6) The method of claim 6, further comprising: generating, by the processing device, an address stored in each account profile of the account database based on application of the associated key to one or more hashing and/or encoding algorithms. ### Claim 8 (depends on 7) The method of claim 7, wherein the one or more hashing and/or encoding algorithms includes the use of Base58Check encoding. ### Claim 9 (depends on 1) The method of claim 1, wherein the transaction message further includes a data element configured to store a personal account number that includes a funding address. ### Claim 10 (depends on 9) The method of claim 9, further comprising: identifying, by the processing device, a funding account profile stored in the account database where the included address corresponds to the funding address; and deducting, by the processing device, the blockchain currency amount included in the identified funding account profile 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 includes adding to the blockchain currency amount based on the transaction amount included in the data element in the received transaction message. ### Claim 11 A system for managing fractional reserves of blockchain currency, comprising: a receiving device configured to receive a transaction message associated with a payment transaction transmitted via payment rails associated with a payment network, wherein the transaction message is formatted based on a standard 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, and a processing device configured to identify a specific account profile stored in an account database that includes the specific address included in the data element in the received transaction message, wherein the specific account profile further includes a fiat currency amount and a blockchain currency amount, and update the blockchain currency amount included in the identified specific account profile based on the transaction amount included in the data element in the received transaction message. ### Claim 12 (depends on 11) The system of claim 11, wherein the processing device is further configured to update the blockchain amount stored in a second central account based on the transaction amount included in the data element in the received transaction message. ### Claim 13 (depends on 11) The system of claim 11, wherein the blockchain amount stored in a second central account is based on a sum of the blockchain currency amounts included in each account profile stored in the account database. ### Claim 14 (depends on 11) The system of claim 11, wherein the processing device is further configured to initiate a blockchain transaction using a blockchain network associated with the blockchain currency amount, wherein the blockchain transaction is for the transaction amount to or from the specific address. ### Claim 15 (depends on 11) The system of claim 11, wherein the standard includes at least the ISO 8583 standard. ### Claim 16 (depends on 11) The system of claim 11, wherein a second central account is configured to store a plurality of keys, each key associated with an account profile stored in the account database. ### Claim 17 (depends on 16) The system of claim 16, wherein the processing device is further configured to generate an address stored in each account profile of the account database based on application of the associated key to one or more hashing and/or encoding algorithms. ### Claim 18 (depends on 17) The system of claim 17, wherein the one or more hashing and/or encoding algorithms includes the use of Base58Check encoding. ### Claim 19 (depends on 11) The system of claim 11, wherein the transaction message further includes a data element configured to store a personal account number that includes a funding address. ### Claim 20 (depends on 19) The system of claim 19, wherein the processing device is further configured to identify a funding account profile stored in the account database where the included address corresponds to the funding address, and deduct the blockchain currency amount included in the identified funding account profile based on the transaction amount included in the data element in the received transaction message, and wherein updating the blockchain currency amount included in the identified specific account profile includes adding to the blockchain currency amount based on the transaction amount included in the data element in the received transaction message.