# US 12,010,228 B2 · Systems, methods, and devices for secure blockchain transaction and subnetworks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,010,228 B2 - Document ID: US12010228B2 - Status: Granted - Kind: B2 - Application number: 17/049,982 - Filed: 2019-03-27 - Published: 2021-03-18 - Granted: 2024-06-11 - Earliest claimed: 2018-05-15 - Assignees: Kelvin Zero Inc. - Applicants: Kelvin Zero Inc. - Inventors: Philippe Desmarais; Thierry St-Jacques-Gagnon - Web page: https://patentgrep.com/patent/US12010228B2 ## CPC - G06Q 20/3829: {involving key management} - H04L 9/0894: {Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage} - G06F 21/74: operating in dual or compartmented mode, i.e. at least one secure mode - G06F 21/85: interconnection devices, e.g. bus-connected or in-line devices - G06Q 20/065: {using e-cash} - G06Q 20/3674: {involving authentication} - G06Q 20/3825: {Use of electronic signatures} - G06Q 20/401: {Transaction verification} - H04L 9/0825: {using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates} - H04L 9/3239: {involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD} - H04L 9/3247: {involving digital signatures} - H04L 9/3255: {using group based signatures, e.g. ring or threshold signatures} - H04L 63/0227: {Filtering policies (mail message filtering H04L51/212)} - H04L 63/123: {received data contents, e.g. message integrity} - G06Q 2220/00: Business processing using cryptography - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - H04L 2209/56: Financial cryptography, e.g. electronic payment or e-cash - 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) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Provided herein is a system, device, method, and subnetwork for performing a secure blockchain transaction of a digital asset. The system includes a terminal for generating the blockchain transaction, the terminal configured to operate in a first mode and a second mode, and a switch connector for preventing the terminal from operating in the first mode and the second mode simultaneously. When the terminal is in the first mode, the terminal is connected via a network to a system provider server, the system provider server in communication with a plurality of blockchain devices. When the terminal is in the second mode, the terminal is in communication with a cold storage device. The cold storage device is configured to store a private key for signing the blockchain transaction. The terminal is configured to sign the blockchain transaction on the cold storage device using the private key. ## Claims ### Claim 1 A system for performing a secure blockchain transaction, the system comprising: a terminal for generating the blockchain transaction, the terminal configured to operate in a first mode and a second mode; and a switch connector for preventing the terminal from operating in the first mode and the second mode simultaneously; wherein, when the terminal is in the first mode, the terminal is connected via a network to a system provider server, the system provider server in communication with at least one blockchain device; wherein, when the terminal is in the second mode, the terminal is in communication with a cold storage device; wherein the cold storage device is configured to store a private key for signing the blockchain transaction; wherein the terminal is configured to allow the blockchain transaction to be signed on the cold storage device using the private key; wherein each of a user of the terminal, a system provider providing the system provider server, and a service provider store a fragment of back-up information for backing up private blockchain information; wherein the private blockchain information is recoverable only when at least two fragments of the back-up information are provided. ### Claim 2 (depends on 1) The system of claim 1, wherein the switch connector comprises a hardware switch. ### Claim 3 (depends on 1) The system of claim 1, wherein the switch connector comprises a software switch. ### Claim 4 (depends on 1) The system of claim 1, wherein the blockchain transaction is signed by at least two parties prior to sending the signed blockchain transaction to the at least one blockchain device. ### Claim 5 (depends on 4) The system of claim 4, wherein the at least one other party includes the system provider. ### Claim 6 (depends on 1) The system of claim 1, wherein the system provider server is in communication with at least one service provider device. ### Claim 7 (depends on 1) The system of claim 1, wherein the back-up information is a key. ### Claim 8 (depends on 1) The system of claim 1, wherein the private blockchain information includes the private key. ### Claim 9 A terminal for performing a secure blockchain transaction, the terminal comprising: a processor for generating an unsigned blockchain transaction; a cold storage communication port for transmitting the unsigned blockchain transaction to a cold storage device, wherein the cold storage device stores a private key for signing the unsigned blockchain transaction, and wherein the terminal receives a signed blockchain transaction from the cold storage device; a network communication port for transmitting the signed blockchain transaction to a system provider server over a network, wherein the system provider server is in communication with at least one blockchain device; a switch connector for selectively disabling either the cold storage communication port or the network communication port such that the private key is not exposed to the network; wherein each of a user of the terminal, a system provider providing the system provider server, and a service provider store a fragment of back-up information for backing up private blockchain information; wherein the private blockchain information is recoverable only when at least two fragments of the back-up information are provided. ### Claim 10 (depends on 9) The terminal of claim 9, wherein the switch connector comprises a hardware switch. ### Claim 11 (depends on 9) The terminal of claim 9, wherein the switch connector comprises a software switch. ### Claim 12 (depends on 9) The terminal of claim 9 further configured to restrict inbound and outbound communication with the system provider server. ### Claim 13 A cold storage device for performing a secure blockchain transaction of a digital asset over a network, the cold storage device comprising: a memory storing a private key of at least one cold storage wallet, the private key for signing an unsigned blockchain transaction; a communication interface for receiving an unsigned blockchain transaction from a terminal, the terminal disconnected from the network; and wherein the communication interface transmits a signed blockchain transaction to the terminal, the terminal disconnected from the network; a connection to a processor configured to sign the unsigned blockchain transaction using the private key; wherein each of a user of the terminal, a system provider, and a service provider store a fragment of back-up information for backing up private blockchain information; wherein the private blockchain information is recoverable only when at least two fragments of the back-up information are provided. ### Claim 14 (depends on 13) The device of claim 13, wherein the communication interface uses at least one communication mechanism selected from the group consisting of encrypted Bluetooth, near-field communication, Wi-Fi, optical communication, wired communication, and thermal emission. ### Claim 15 (depends on 13) The device of claim 13, wherein the processor is further configured to generate a key pair of the at least one cold storage wallet. ### Claim 16 (depends on 15) The device of claim 15, wherein the at least one cold storage wallet is a hierarchical deterministic wallet. ### Claim 17 A method of performing a secure blockchain transaction over a communication network, the method comprising: generating an unsigned blockchain transaction using a terminal, the terminal having an online mode and an offline mode; transmitting, in the offline mode, the unsigned blockchain transaction from the terminal to a cold storage device, the cold storage device storing a private key for signing the unsigned blockchain transaction; signing the unsigned blockchain transaction on the cold storage device using the private key; transmitting the signed blockchain transaction from the cold storage device to the terminal; switching the terminal from the offline mode to the online mode; transmitting the signed blockchain transaction from the terminal to a system provider server via the communication network while in the online mode, the system provider server in communication with a plurality of blockchain computers; wherein each of a user of the terminal, a system provider providing the system provider server, and a service provider store a fragment of back-up information for backing up private blockchain information; wherein the private blockchain information is recoverable only when at least two fragments of the back-up information are provided. ### Claim 18 (depends on 17) The method of claim 17, further comprising signing the transmitted signed transaction with a second private key according to a multi-signature authentication process. ### Claim 19 (depends on 18) The method of claim 18, wherein signing the transmitted signed transaction is performed on the system provider server. ### Claim 20 (depends on 17) The method of claim 17, wherein the switching is performed using a switch connector. ### Claim 21 (depends on 20) The method of claim 20, wherein the switch connector is a hardware switch connector. ### Claim 22 (depends on 20) The method of claim 20, wherein the switch connector is a software switch connector.