System and method for backing up and recovering crypto wallets

Abstract

Systems, methods and devices for backing up and recovering crypto wallets. The crypto wallet may interoperate with multiple removable authentication devices that may work in tandem to recover access to the crypto wallet if the PIN and / or seed value of the crypto wallet is lost or forgotten. By implementing multiple removable authentication devices, two-person (or more) integrity (TPI) is achieved to ameliorate the risk of theft by requiring the multiple devices to operate in tandem by different users who know different PINs for different removable authentication devices to recover access to the crypto wallet.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on and claims priority to U.S. Provisional Patent Application No. 63 / 305,612, entitled "SYSTEM AND METHOD FOR BACKING UP AND RECOVERING CRYPTO WALLETS," filed on February 1, 2022, the entire contents of which are incorporated herein by reference.

[0002] 1. Field

[0003] The present disclosure is directed to crypto wallets, and more specifically, the present disclosure is directed to backup and recovery of crypto wallets. [Background technology]

[0004] 2. Description of the Prior Art

[0005] Crypto wallets are used to generate and store cryptographic keys required to perform cryptocurrency transactions. The private keys of a crypto wallet are typically generated by a deterministic hierarchical scheme based on one master secret, called a seed value. If a hardware wallet is damaged, lost, or stolen, or if the wallet owner forgets the password or PIN code that secures access to the wallet, the owner can restore the wallet if he knows the seed value. However, if the owner does not know or has forgotten the seed value, the wallet is typically unrecoverable. Furthermore, if the owner is incapacitated or deceased, the wallet is typically unrecoverable. Therefore, other methods of restoring crypto wallets are needed. Summary of the Invention [Problem to be solved by the invention]

[0006] Systems, methods and devices for backing up and recovering crypto wallets are provided. In various embodiments, a method for recovering electronic access to a cryptocurrency wallet of a hardware wallet device may have various aspects. For example, the method may include connecting the hardware wallet device to a physically attached removable authentication device in electronic communication with the hardware wallet device. The method may include receiving a personal identification number (PIN) sequence by a user input component of the hardware wallet device. The method may include comparing, by the removable authentication device, the PIN sequence to a stored PIN stored in the removable authentication device. The method may include, in response to a match between the stored PIN and the PIN sequence, obtaining, by the hardware wallet device, a secret share from the removable authentication device and storing the secret share in the hardware wallet device. The method may include determining that a number of secret shares stored in the hardware wallet device meets or exceeds a first threshold. The method may include, in response to the number of secret shares stored on the hardware wallet device meeting or exceeding a first threshold, applying a first secret sharing technique to the secret shares stored on the hardware wallet device to recover a seed value for the hardware wallet device and storing the recovered seed value in the hardware wallet device. The method may include, in response to the number of secret shares stored on the hardware wallet device not meeting or exceeding the first threshold, displaying a message on a user output component of the hardware wallet device instructing a user to physically attach to the hardware wallet device one or more additional removable authentication devices in electronic communication with the hardware wallet device. [Means for solving the problem]

[0007] The method may have one or more alternative aspects. For example, the method may further comprise, after displaying the message on a user output component of the authentication device, connecting the hardware wallet device to one or more additional removable authentication devices in electronic communication with the hardware wallet device.

[0008] In various embodiments, one or more additional removable authentication devices may be connected in series or in series. In various embodiments, one or more additional removable authentication devices may be connected in parallel. In various embodiments, the stored PIN stored in the removable authentication device is not revealed to the hardware wallet device. In various embodiments, the stored PIN stored in the removable authentication device is not revealed to the hardware wallet device or any other device.

[0009] The method may have other aspects. For example, the method may include receiving, by a user input component of the hardware wallet device, an additional personal identification number (PIN) sequence. The method may include comparing, by the one or more additional removable authentication devices, the additional PIN sequence with an additional stored PIN of the one or more additional removable authentication devices. The method may include obtaining, by the hardware wallet device, an additional secret share from the removable authentication device in response to the additional stored PIN matching the additional PIN sequence and storing the additional secret share in the hardware wallet device. The method may include determining that a number of secret shares stored in the hardware wallet device meets or exceeds a first threshold. The method may include applying a first secret sharing technique to the secret shares stored in the hardware wallet device to recover a seed value for the hardware wallet device in response to the number of secret shares stored in the hardware wallet device meeting or exceeding the first threshold and storing the recovered seed value in the hardware wallet device. In one aspect, the first secret sharing technique may be Shamir's secret sharing technique.

[0010] The method may have other aspects. The method may include notifying a trusted server of the seed value recovery attempt by the hardware wallet device. The method may include sending, by the trusted server, a rejection message to the user electronic messaging platform. The method may include receiving, by the trusted server, the rejection message from the user electronic messaging platform. The method may include providing, by the trusted server, the rejection message to the hardware wallet device. The method may include, by the hardware wallet device, aborting the method and rejecting recovery of the seed value in response to receiving the rejection message.

[0011] A method for establishing electronic access recovery credentials for a cryptocurrency wallet of a hardware wallet device is provided. The method may include setting, at the hardware wallet device, a first number N of secret shares generated based on a seed value. The method may include setting, at the hardware wallet device, a second number M of secret shares less than or equal to N required to recover the seed value. The method may include applying, by the hardware wallet device, a first secret sharing technique to generate the first number N of secret shares from the seed value. The method may include communicating, by the hardware wallet device, with an attached removable authentication device. The method may include receiving a PIN sequence from a user input component of the hardware wallet device. The method may include setting, by the hardware wallet device, a PIN stored in the removable authentication device to the PIN sequence. The method may include storing, by the hardware wallet device, a first secret share of the first number N of secret shares of the hardware wallet device in a remote authentication device having the PIN sequence. The method may include displaying, on a user output component of the hardware wallet device, a message instructing a user to physically attach to the hardware wallet device one or more additional removable authentication devices in electronic communication with the hardware wallet device.

[0012] The method may have one or more alternative aspects. For example, the method may include, after displaying the message on a user output component of the authentication device, connecting the hardware wallet device to one or more additional removable authentication devices in electronic communication with the hardware wallet device. In various embodiments, the one or more additional removable authentication devices are connected in series or in series. In various embodiments, the one or more additional removable authentication devices are connected in parallel.

[0013] The method may include communicating, by the hardware wallet device, with another attached removable authentication device of the one or more additional removable authentication devices. The method may include receiving a different PIN sequence from a user input component of the hardware wallet device. The method may also include setting, by the hardware wallet device, a different PIN stored in the different removable authentication device to a different PIN sequence. The method may also include storing, by the hardware wallet device, a different secret share of the first number N of shares of the hardware wallet device's secret in a different remote authentication device having a different PIN sequence. The first secret sharing technique may be Shamir's secret sharing technique.

[0014] A hardware wallet device is disclosed that provides an electronically accessible cryptocurrency wallet. The hardware wallet device may have a user input component configured to receive a personal identification number (PIN) sequence from a user. The hardware wallet device may have a removable authentication device reader configured to be physically attached to a physically attachable removable authentication device containing a stored PIN and to electronically communicatively connect the removable authentication device to a processor. The hardware wallet device may have a processor configured to communicate with the removable authentication device to compare the PIN sequence with the stored PIN by the removable authentication device, and further configured to retrieve secret shares from the removable authentication device in response to the PIN sequence matching the stored PIN. The hardware wallet device may have a digital storage device configured to store the secret shares retrieved from the removable authentication device. The processor may be further configured to determine whether a number of secret shares stored in the hardware wallet device meets or exceeds a first threshold. The processor may, in response to the number of secret shares stored in the digital storage of the hardware wallet device meeting or exceeding a first threshold, apply a first secret sharing technique to the secret shares stored in the digital storage to recover a seed value for the hardware wallet device and store the recovered seed value in the digital storage. In response to the number of secret shares stored in the digital storage not meeting or exceeding the first threshold, the processor may display a message on a user output component of the hardware wallet device instructing the user to physically attach to the hardware wallet device one or more additional removable authentication devices in electronic communication with the hardware wallet device.

[0015] The hardware wallet device may have other aspects, such as, after displaying a message on a user output component of the authentication device, one or more additional removable authentication devices are connected in electronic communication with the hardware wallet device, one or more additional removable authentication devices are connected in series or serially, one or more additional removable authentication devices are connected in parallel,

[0016] The user input component may be configured to receive an additional personal identification number (PIN) sequence. The processor may be configured to communicate with the one or more additional removable devices to compare the additional PIN sequence with an additional stored PIN of the one or more additional removable authentication devices by the one or more additional removable devices. The processor may be configured to obtain an additional secret share from the removable authentication device in response to the additional stored PIN matching the additional PIN sequence and store the additional secret share in the digital storage of the hardware wallet device. The processor may determine that a number of secret shares stored in the digital storage of the hardware wallet device meets or exceeds a first threshold, and the processor may apply a first secret sharing technique to the secret shares stored in the digital storage to recover a seed value for the hardware wallet device in response to the number of secret shares stored in the hardware wallet device meeting or exceeding the first threshold and store the recovered seed value in the digital storage. The first secret sharing technique may include Shamir's secret sharing scheme.

[0017] In various embodiments, the hardware wallet device further comprises a communication device coupled to the processor, the communication device configured to notify a trusted server of the seed value recovery attempt. The trusted server may be configured to send a denial rejection message to the user electronic messaging platform. The trusted server may be configured to receive the denial message from the user electronic messaging platform. The trusted server may be configured to provide the denial message to the hardware wallet device. The processor of the hardware wallet device may be configured to reject recovery of the seed value in response to receiving the denial message. [Brief description of the drawings]

[0018] Other systems, methods, features, and advantages of the present invention will be apparent to one with skill in the art upon examination of the following figures and detailed description. Components illustrated in the drawings are not necessarily to scale and may be exaggerated to more clearly illustrate the important features of the present invention.

[0019] [Figure 1A] FIG. 1A is a block diagram of a crypto wallet backup and recovery system in accordance with various aspects.

[0020] [Figure 1B] FIG. 1B illustrates an example implementation of the system of FIG. 1A in accordance with various embodiments.

[0021] [Diagram 2] FIG. 2 illustrates a method for generating a recovery seed phrase according to various aspects.

[0022] [Diagram 3] FIG. 3 illustrates a method for recovering a crypto wallet using a recovery seed phrase according to various aspects.

[0023] [Figure 4]FIG. 4 illustrates a method for backing up a seed value according to various aspects.

[0024] [Diagram 5] FIG. 5 illustrates a method for recovering a crypto wallet using a seed value according to various aspects.

[0025] [Figure 6] FIG. 6 illustrates a method for establishing electronic access recovery credentials for a cryptocurrency wallet of a hardware wallet device in accordance with various aspects.

[0026] [Figure 7] FIG. 7 illustrates a method of recovering electronic access to a cryptocurrency wallet of a hardware wallet device according to various embodiments.

[0027] [Figure 8] FIG. 8 illustrates a method for suspending recovery of a crypto wallet in accordance with various aspects.

[0028] [Figure 9] FIG. 9 illustrates a method for payload signing and verification by a crypto wallet in accordance with various aspects.

[0029] [Figure 10] FIG. 10 illustrates a method for signing and approving a transaction with a crypto wallet according to various aspects. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] As disclosed herein, systems, apparatus and methods are provided for backing up and recovering cryptocurrency wallets ("crypto wallets").

[0031] Crypto wallets are used to generate and store cryptographic keys required to perform cryptocurrency transactions. There are at least two common types of crypto wallets: A software wallet is a crypto wallet that is a smartphone or desktop application that stores cryptographic keys and also manages incoming and outgoing transactions. A hardware wallet is a crypto wallet that has an embedded device that stores a private key used to sign outgoing transactions. The hardware wallet communicates with a smartphone, desktop or web application "watch-only wallet" that stores only the public key that corresponds to the hardware wallet's private key. The watch-only wallet monitors incoming transactions and prepares outgoing unsigned transactions for the embedded device, but cannot sign outgoing transactions. The embedded device verifies the transaction details, obtains the appropriate signing key, signs the transaction, and sends the signed transaction back to the smartphone, desktop or web application for broadcast to mining nodes.

[0032] Hardware crypto wallets are known to be more secure than software crypto wallets because the private keys never leave the embedded device, whereas software crypto wallets coexist with other applications on a smartphone or desktop and are therefore susceptible to shared platform software attacks. Access to the operation of a hardware crypto wallet is often protected by a personal identification number (PIN).

[0033] The private keys of a crypto wallet may be generated by a deterministic hierarchical scheme based on one master secret. The master secret is called the seed value. To this end, an algorithm may convert the seed value into a sequence or word known as a recovery seed phrase that the wallet owner can write down on paper and store in a safe place. However, the recovery seed phrase itself can be lost or stolen. Furthermore, the lack of succession planning is a significant risk for hardware wallets. For example, if the wallet owner dies or becomes a guardian without disclosing the hardware wallet PIN or recovery seed phrase to others, the cryptocurrency associated with the hardware wallet may be lost.

[0034] The systems, devices and methods provided herein address these and other concerns. The systems, devices and methods provide various backup mechanisms, including mechanisms that use smart cards (secure elements). A smart card is a token with a microprocessor that stores and / or processes confidential material for the benefit of a larger device. A secure element is a tamper-resistant platform that can securely host (e.g., key management) applications and their sensitive and cryptographic data, and may be a type of smart card.

[0035] In some examples, the backup information accessible to the crypto wallet may be stored with the seed value via the wallet owner's smart card and protected by a PIN that the owner sets when preparing the backup. In other examples, the backup information accessible to the crypto wallet may be stored with shares of the seed value via a group of smart cards that the wallet owner can give to an administrator and protected by a PIN that the owner sets when preparing the backup. The shares are generated such that the seed value can be restored if there is a predefined minimum number of shares, while each individual share and the subset of shares below the minimum number for seed value reconstruction provide no information about the seed value. For example, Shamir's Secret Sharing (SSS) may be performed. In SSS, any T of the N shares may be used to restore the secret. This system relies on the principle that a unique polynomial of degree T-1 can be fitted to any set of T points in the polynomial. That is, it takes T points to define a polynomial of degree T-1. Thus, one may distribute the backup information among the individual shares by constructing a polynomial of degree T-1 with the secret as the first coefficient and the remaining coefficients chosen randomly, finding N points on the curve, and giving one to each trustee. When at least T of the N shares are revealed, there is enough information to fit a polynomial of degree T-1 to it, with the first coefficient being the secret.

[0036] An exemplary system for backing up and recovering a crypto wallet may include different devices that work together to perform these mechanisms. Turning now to the combination of Figures 1A and 1B, a system 2 for backing up and recovering a crypto wallet may include one or more wallet devices 4. The wallet device 4 may be a hardware crypto wallet embedded device. For example, the wallet device 4 may have processing, communication and memory capabilities. The system 2 may include a remote control device 6. The remote control device 6 may be a device that can control cryptocurrency transactions in conjunction with the wallet device 4, but cannot access private keys securely stored within the wallet device 4. The system 2 may include one or more removable authentication devices 8. The removable authentication device 8 may be removably connectable to and removable from the wallet device 4. For example, the removable authentication device 8 may include a smart card that can be inserted into the wallet device 4 and electronically communicate with the wallet device 4. The removable authentication device 8 may include a seed value or may include shares that, in combination with shares of other removable authentication devices 8, reveal a seed value.

[0037] Considering now the wallet device 4, the remote control device 6, and the removable authentication device 8 in more detail. In various embodiments, the wallet device 4 may include a processor 10. The processor 10 may be a computer processor, a microprocessor, or any other electronic device configured to perform calculations. The wallet device 4 may include a digital storage device 12. The digital storage device 12 may include electronic memory. The memory may interoperate with the processor 10 to store data for future use and to retrieve data for current use. In various embodiments, the digital storage device 12 may include securely stored private keys, or one or more seed values, one or more pin numbers, and / or one or more shares that, in combination, interoperate to reveal one or more seed values. The wallet device 4 may include a user input component 14. The user input component 14 may include one or more keyboards, push buttons, touch-sensitive elements such as a touch screen, audio devices, haptic devices, and / or other human-machine interfaces capable of receiving input from a human. The wallet device 4 may include one or more user output components 16. The user output component 16 may include one or more visual display screens, light indicators, audio devices, haptic devices, and / or other human-machine interfaces capable of providing output to a human. The wallet device 4 may include one or more removable authentication device readers 18. The removable authentication device reader 18 may include an electronic hardware module having a connection connectable to the removable authentication device 8 to interconnect the removable authentication device 8 and the processor 10 for data exchange. The removable authentication device reader 18 may include a smart card slot into which the removable authentication device 8 having a smart card may be physically inserted.The wallet device 4 may comprise a communication device 21 configured to communicate with other devices, such as a remote control device 6, a network, or a trusted server 24 over a network.

[0038] 1B, wallet device 4 may have a user input component 14 having a number of push buttons and a user output component 16 having an LCD or other visual screen display. Removable authentication device reader 18 may be a smart card slot and reader for accepting removable authentication device 8 including an insertable smart card.

[0039] 1A and 1B, the remote control device 6 may include an application running on a smartphone 7. In another example, the remote control device 6 is a dedicated device configured to initiate cryptocurrency transactions. Cryptocurrency transactions initiated by the remote control device may or may not be authorized by the wallet device 4, which securely holds the associated private key(s). Thus, the remote control device 6 may be configured to communicate with the wallet device 4, and in particular, the communication device 21 of the wallet device 4.

[0040] The removable authentication device 8 may include a smart card, as described above. The removable authentication device 8 may have a processor 20 configured to perform encryption or other operations, and a memory 22 configured to store data. In various embodiments, the memory 22 may store a seed value. The memory 22 may store shares of the seed value according to Shamir's secret sharing technique. The memory 22 may store a personal identification number (PIN) associated with unlocking or revealing the seed value or shares. The processor 20 of the removable authentication device 8 may determine whether a provided PIN number (such as a PIN entered into the user input component 14 by a user of the wallet device 4) matches a PIN stored in the memory 22. The processor 20 may perform this operation without revealing the correct PIN to any device outside the removable authentication device 8. In this manner, the correct PIN stored in the memory 22 is protected from attempts to discover, compromise, or destroy the PIN. In one aspect, the PIN associated with the smart card (the removable authentication device 8) is verified by the card itself, not the hardware wallet. In various embodiments, the removable authentication device 8 does not allow access to the PIN associated with the removable authentication device 8 or reveal the PIN associated with the removable authentication device 8 to anyone.

[0041] Finally, system 2 may also include a trusted server 24. Trusted server 24 may be operatively connectable to wallet device 4. Trusted server 24 may communicate with wallet device 4 in connection with cryptocurrency transactions. Aspects of communication with trusted server 24 are disclosed herein.

[0042] Having now introduced details of the system 2 and its components, we now provide an example architecture of the system 2 with some or all of its components. Briefly, the system 2 may include a hardware crypto wallet embedded device (wallet device 4). This device may include one or more processors 10, one or more digital storage devices 12, one or more user input components 14 such as buttons, one or more user output components 16 such as a display, and / or one or more removable authentication device readers 18 such as a physical interface (e.g., slot) for a smart card. The system 2 may include multiple removable authentication devices 8 (e.g., smart cards), each of which includes a processor 20 and a memory 22 providing secure storage. A remote control device 6 such as a smartphone, desktop application, or web application may communicate with the embedded device via a wireless communication protocol (e.g., Bluetooth Low Energy (BLE)®) or a cable-based communication protocol (e.g., Universal Serial Bus (USB)). The wallet device 4 may include a communication device 21 capable of communicating with the wireless communication protocol.

[0043] Wallet device 4 may have various functionalities. For example, wallet device 4 may require the user to set a PIN, allow the user to enter the PIN via one or more buttons or touch keys, and securely store the PIN. Wallet device 4 may require the user to re-enter the PIN via one or more buttons or touch keys to unlock the device before each use, and successful entry of the PIN unlocks the device for a period of time. Wallet device 4 may erase all keys and reset wallet device 4 if the PIN is entered incorrectly a predetermined number of consecutive times. In various embodiments, the PIN is stored in a removable authentication device 8 attached to wallet device 4 such that the correct PIN is not revealed to wallet device 4, and wallet device 4 receives the entered PIN and provides the entered PIN to removable authentication device 8, which compares it to the securely stored PIN.

[0044] In various embodiments, wallet device 4 stores a seed value for the wallet. The seed value can be obtained in various ways. For example, when a new wallet is created, wallet device 4 may randomly generate a seed value. In this case, wallet device 4 may also allow the wallet owner to prepare one or more backup options, as described below. In another example, the seed value of an existing wallet is recovered by one of the following backup options:

[0045] In various embodiments, the backup option may include the use of a recovery seed phrase. With joint reference to FIGS. 1A, 1B, and 2, in an exemplary implementation, a method 200 for generating a recovery seed phrase may proceed as follows: To create a backup, the processor 10 of the wallet device 4 may convert a seed value into a seed phrase (block 210). The wallet device 4 may display a sequence of characters or words of the seed phrase on the user output component 16 of the wallet device 4 (block 220). With reference to FIGS. 1A, 1B, and 3, a method 300 for recovering a crypto wallet using a recovery seed phrase is provided. The wallet device 4 may receive a sequence of characters or words of the seed phrase from a user via the user input component 14 (block 310). The wallet device 4 may convert the seed phrase into a seed value (block 320). The recovered seed value is then securely stored in the digital storage device 12 of the wallet device 4 (block 330).

[0046] 1A, 1B, and 4, in an exemplary implementation, a method 400 for backing up a seed value is provided. The method may include the wallet device 4 communicating with the attached removable authentication device 8 via the removable authentication device reader 18 of the wallet device 4 (block 410). Such communication may be via a contact or contactless interface such as ISO-7816, USB, I2C, NFC, etc. The method may include receiving a PIN sequence from the user input component 14 of the wallet device 4 (block 420). The method may include setting, by the wallet device 4, a PIN stored in the removable authentication device 8 to the PIN sequence (block 430). The method may include storing, by the wallet device 4, the seed value of the wallet device 4 in the removable authentication device 8 with the PIN set to the PIN sequence (block 440).

[0047] 1A, 1B and 5, in an exemplary implementation, a method 500 for recovering a crypto wallet using a seed value may include, by the wallet device 4, connecting with an attached removable authentication device 8 (block 510). The method 500 may include receiving a PIN sequence from a user input component 14 of the wallet device 4 (block 520). The method may include comparing the PIN sequence with a PIN stored in the removable authentication device 8 (block 530). In response to the PIN sequence not matching the PIN, the removable authentication device 8 increments a failed attempt counter stored in the removable authentication device 8 (block 560) and ends the method (block 570). After a pre-configured number of failed attempts, the removable authentication device 8 may erase its data and reset. In response to the PIN sequence matching the PIN, the wallet device 4 retrieves a seed value from the removable authentication device 8 (block 540). The wallet device 4 stores the seed value in the wallet device 4 (block 550).

[0048] In another example, a method is provided for both backing up a seed value on shares of multiple removable authentication devices working in conjunction with each other, and for recovering a seed value via shares of multiple removable authentication devices. However, before describing these methods in detail with reference to the figures, a brief summary is useful.

[0049] In various embodiments, the wallet device 4 has the following parameters with default values ​​that can be changed by the user: (1) the total number of shares of the secret N that will be generated based on the seed value (N is greater than 1 and less than or equal to the number of smart cards available); and (2) the minimum number or threshold M of shares of the secret that are required to be present in order to recover the seed value (M is greater than 1 and less than or equal to the total number of shares).

[0050] To create a backup of the seed value, wallet device 4 applies a secret sharing scheme, e.g., Shamir's secret sharing scheme, to calculate the values ​​of each of the secret shares based on the seed value such that (1) knowing the values ​​of any number of shares does not reveal any information about the seed value if the number of shares is less than a specified threshold M, and (2) knowing the values ​​of any number of shares is sufficient to recover the seed value if the number of shares is greater than or equal to the specified threshold M.

[0051] After calculating the share values, wallet device 4 may communicate with the first removable authentication device 8 via removable authentication device reader 18. Wallet device 4 obtains a first PIN for the removable authentication device from the user via user input component 14 and sets the first PIN in the first removable authentication device 8. Wallet device 4 stores the first secret share in the first removable authentication device 8. This process is repeated to write a second secret share and a second PIN to the second removable authentication device 8, etc. until each of the secret shares has been written to a different removable authentication device 8.

[0052] To protect the backup, each removable authentication device 8 (1) securely stores the PIN and secret, (2) requires re-entry of the PIN to reveal the secret, and (3) erases the secret and resets removable authentication device 8 if the PIN is entered incorrectly a certain number of consecutive times.

[0053] To recover the seed value from the shares of the multiple removable authentication devices 8, wallet device 4 may communicate with a first removable authentication device 8 via removable authentication device reader 18. Wallet device 4 may obtain a first PIN for the first removable authentication device 8 from a user via user input component 14 of wallet device 4. Wallet device 4 may write the first PIN to the first removable authentication device 8. Wallet device 4 may obtain a first secret share from the first removable authentication device 8 if the PIN is correct. Wallet device 4 may temporarily store the first secret share.

[0054] This process is repeated to obtain a second secret share from the second removable authentication device 8 until the number of distinct secret shares matches the threshold for successful reconstruction of the seed value.

[0055] The system requires that the wallet owner be notified by the wallet by sending an email, message, app notification, etc. from the wallet to the trusted server 24, which then forwards the transfer to the wallet owner account included in the wallet certificate. The trusted server 24 ensures that the wallet owner does not stop the takeover process by responding to any of these notifications for a certain period of time (such as one or two months), after which the trusted server 24 responds to the wallet with a signed message to approve the takeover process. The wallet verifies the trusted server 24 signature against a previously stored server public key before proceeding with the takeover process. The wallet owner sets the duration of the takeover delay when setting up the wallet. When the wallet device 4 obtains a number of distinct secret shares that match the reconstruction success threshold, it applies the corresponding secret recovery method to recover the seed value. The wallet device 4 then securely stores the recovered seed value.

[0056] Having introduced the concepts of creating a backup of a seed value and recovering the seed value from shares of multiple removable authentication devices 8, attention is directed to various figures for a more detailed discussion of examples. With joint reference to FIGS. 1A, 1B and 6, an embodiment provides a method 600 for establishing electronic access recovery credentials for a cryptocurrency wallet of a hardware wallet device. The method may include setting at the hardware wallet device 4 a first number N of secret shares to be generated based on the seed value (block 602). The method may include setting at the hardware wallet device 4 a second number M less than or equal to N of secret shares required to recover the seed value (block 604). The method may include applying, by the hardware wallet device 4, a first secret sharing technique to generate the first number N of secret shares from the seed value (block 606). The method may include communicating, by the hardware wallet device 4, with the attached removable authentication device 8 (block 608). The method may include receiving a PIN sequence from a user input component 14 of the hardware wallet device 4 (block 610). The method may include setting, by the hardware wallet device 4, the PIN stored in the removable authentication device 8 to the PIN sequence (block 612). The method may include storing, by the hardware wallet device 4, a first secret share of a first number N of secret shares of the hardware wallet device 4 in the removable authentication device 8 with the PIN sequence (block 614). The method may include displaying, on the user output component 16 of the hardware wallet device 4, a message instructing the user to physically attach to the hardware wallet device 4 one or more additional removable authentication devices 8 in electronic communication with the hardware wallet device 4 (block 616). The hardware wallet device 4 may determine whether all secret shares have been stored in the removable authentication device 8 (block 618).In response to the inquiry being "true," the method ends (block 620), otherwise the method proceeds to disconnect the attached removable authentication device 8 and attach a different removable authentication device 8 to the wallet device 4 (block 622). The method returns to block 608.

[0057] 1A, 1B, and 7, in an exemplary implementation, a method 700 for recovering electronic access to a cryptocurrency wallet of a hardware wallet device 4 is provided. The method may include connecting the hardware wallet device 4 to a physically attached removable authentication device 8 in electronic communication with the hardware wallet device 4 (block 702). The method may include receiving a PIN sequence by a user input component 14 of the hardware wallet device 4 (block 704). The method may include comparing the PIN sequence to a stored PIN stored in the removable authentication device 8 by the processor 10 of the hardware wallet device 4 and / or the processor 20 of the removable authentication device 8 (block 706). The method may include retrieving, by the hardware wallet device 4, a secret share from the removable authentication device 8 in response to the stored PIN matching the PIN sequence and storing the secret share in the digital storage device 12 of the hardware wallet device 4 (block 708). The method may further include determining whether a number of stored secret shares of the hardware wallet device 4 meets or exceeds a first threshold (block 710). Further, if at block 706 the PIN sequence and the stored PIN do not match, the method skips block 708 and proceeds directly to block 710. In response to the number of stored secret shares of the hardware wallet device 4 meeting or exceeding the first threshold, the processor 10 of the wallet device 4 applies the first secret sharing technique to the stored secret shares of the hardware wallet device 4 to recover a seed value of the hardware wallet device 4, and stores, by the hardware wallet device 4, the recovered seed value of the hardware wallet device 4 in the digital storage device 12 of the hardware wallet device 4 (block 714).In response to the number of stored secret shares in the hardware wallet device 4 not meeting or exceeding the first threshold (block 710), the user output component 16 of the hardware wallet device 4 displays a message (block 711) instructing the user to physically attach to the hardware wallet device 4 one or more additional removable authentication devices 8 that are in electronic communication with the hardware wallet device 4. The attached removable authentication device 8 is then disconnected and a different removable authentication device 8 is attached to the wallet device 4 (block 712), and the method returns to block 704.

[0058] 1A, 1B and 8, a method 800 for suspending crypto wallet recovery may enable a user to prevent collusion among holders of shares to recover (e.g., access) a wallet against the user's wishes. For example, the method may include notifying the trusted server 24 (block 802) of a seed value recovery attempt according to the methods described above, particularly method 700 of FIG. 7. The wallet device 4 may send a denial message to the trusted server 24 (block 804), which may utilize a user electronic messaging platform such as email, message, app notification, etc. to communicate with the user. In response to the user responding to the denial of recovery (block 806), the recovery is denied (block 812). In response to the user not responding to the denial of recovery, the method may include waiting for a preset time interval to elapse (block 808), after which the wallet device 4 and the trusted server 24 communicate to allow recovery of the credential.

[0059] Finally, the hardware wallet device 4 may perform various cryptographic operations briefly introduced in the previous paragraph. For example, referring to FIG. 1A, FIG. 1B, and FIG. 9, a method 900 of signing and verifying a payload with a cryptographic wallet may include generating, by the wallet device 4, a plurality of private keys from a seed value (block 902). The method may include storing, by the hardware wallet device 4, the plurality of private keys in the digital storage device 12 of the hardware wallet device 4 (block 904). The method may include generating, by the hardware wallet device 4, a public key from at least one private key of the plurality of private keys (block 906). The method may include signing, by the hardware wallet device 4, a payload such as a non-fungible token using the private key to generate a signed payload (block 908). Finally, the method may include verifying, by the hardware wallet device 4, the signature of the signed payload using the public key (block 910).

[0060] 1A, 1B and 10, a method 1000 of transaction signing and approval by a crypto wallet is disclosed. The method may include receiving, by the hardware wallet device 4, a cryptocurrency transaction from the remote control device 6 (block 1002). The method may include parsing, by the hardware wallet device 4, the cryptocurrency transaction to obtain transaction details (block 1004). The method may include displaying, by the hardware wallet device 4, the transaction details on the user output component 16 (block 1006). The method may include requesting, by the hardware wallet device 4, confirmation of the transaction via the user input component 14 (block 1008). In response to the transaction not being confirmed, the transaction is aborted (block 1010). In response to the transaction being confirmed, the transaction is signed by the hardware wallet device 4 using a private key stored in the digital storage device 12 (block 1012). The signed transaction is sent by the hardware wallet device 4 to the remote control device 6 (block 1014).

[0061] Exemplary embodiments of the method / system have been disclosed in an exemplary manner. Accordingly, the terms employed throughout should be read in a non-limiting manner. Although minor modifications to the teachings herein will be familiar to those skilled in the art, it is understood that what is intended to be encompassed within the scope of the patent granted herein are all such embodiments that reasonably fall within the scope of the advancement to the art contributed herein, the scope of which is not to be limited except in light of the appended claims and their equivalents.

Claims

1. 1. A method for recovering electronic access to a cryptocurrency wallet on a hardware wallet device, comprising: connecting the hardware wallet device to a physically attached removable authentication device that is in electronic communication with the hardware wallet device; receiving, by a user input component of the hardware wallet device, a personal identification number (PIN) sequence; comparing, by the removable authentication device, the PIN sequence with a stored PIN stored on the removable authentication device; in response to a match between the stored PIN and the PIN sequence, obtaining, by the hardware wallet device, a secret share from the removable authentication device and storing the secret share in the hardware wallet device; determining that the number of shares of the secret stored on the hardware wallet device meets or exceeds a first threshold; in response to the number of shares of the secret stored on the hardware wallet device meeting or exceeding the first threshold, applying a first secret sharing technique to the shares of the secret stored on the hardware wallet device to recover a seed value for the hardware wallet device and storing the recovered seed value in the hardware wallet device; in response to the number of shares of the secret stored on the hardware wallet device not meeting and not exceeding the first threshold, displaying a message on a user output component of the hardware wallet device instructing a user to physically attach to the hardware wallet device one or more additional removable authentication devices in electronic communication with the hardware wallet device; A method for providing the above.

2. displaying the message on the user output component of the authentication device; 10. The method of claim 1, further comprising connecting the hardware wallet device to the one or more additional removable authentication devices in electronic communication with the hardware wallet device.

3. The method of claim 2 , wherein the one or more additional removable authentication devices are connected in series or in series.

4. The method of claim 1 , wherein the stored PIN stored on the removable authentication device is not revealed to the hardware wallet device.

5. receiving, by the user input component of the hardware wallet device, another personal identification number (PIN) sequence; comparing, by the one or more additional removable authentication devices, the other PIN sequence with a other stored PIN of the one or more additional removable authentication devices; obtaining, by the hardware wallet device, another secret share from the removable authentication device in response to the another stored PIN matching the another PIN sequence, and storing the another secret share in the hardware wallet device; determining that the number of shares of the secret stored on the hardware wallet device meets or exceeds the first threshold; in response to the number of shares of the secret stored on the hardware wallet device meeting or exceeding the first threshold, applying the first secret sharing technique to the shares of the secret stored on the hardware wallet device to recover the seed value of the hardware wallet device, and storing the recovered seed value in the hardware wallet device; The method of claim 2 further comprising:

6. The method of claim 5 , wherein the first secret sharing technique comprises Shamir's secret sharing scheme.

7. notifying a trusted server of a seed value recovery attempt by the hardware wallet device; sending, by said trusted server, a rejection message to a user electronic messaging platform; receiving, by the trusted server, a rejection message from the user electronic messaging platform; providing, by the trusted server, the denial message to the hardware wallet device; by the hardware wallet device, aborting the method and refusing to recover the seed value in response to receiving the refusal message; The method of claim 1 further comprising:

8. 1. A method for establishing electronic access recovery credentials for a cryptocurrency wallet on a hardware wallet device, comprising: establishing, in the hardware wallet device, a first number N of secret shares to be generated based on a seed value; setting, in the hardware wallet device, a second number M of secret shares required to recover the seed value, the second number M being less than or equal to N; applying, by the hardware wallet device, a first secret sharing technique to generate a first number N of secret shares from the seed value; communicating with an attached removable authentication device by said hardware wallet device; receiving a PIN sequence from a user input component of the hardware wallet device; setting, by the hardware wallet device, a PIN stored in the removable authentication device to a PIN sequence; storing, by the hardware wallet device, a first secret share of the first number N of secret shares of the hardware wallet device in a remote authentication device having the PIN sequence; displaying a message on a user output component of the hardware wallet device instructing a user to physically attach to the hardware wallet device one or more additional removable authentication devices in electronic communication with the hardware wallet device; A method for providing the above.

9. displaying the message on the user output component of the authentication device; 10. The method of claim 8, further comprising connecting the hardware wallet device to the one or more additional removable authentication devices in electronic communication with the hardware wallet device.

10. The method of claim 9 , wherein the one or more additional removable authentication devices are connected in series or in series.

11. The method of claim 9 , wherein the one or more additional removable authentication devices are connected in parallel.

12. communicating with another attached removable authentication device of the one or more additional removable authentication devices by the hardware wallet device; receiving another PIN sequence from a user input component of the hardware wallet device; setting, by the hardware wallet device, a different PIN stored in the different removable authentication device to a different PIN sequence; storing, by the hardware wallet device, another secret share of the first number N of secret shares of the hardware wallet device in another remote authentication device having the another PIN sequence; The method of claim 9 further comprising:

13. The method of claim 9 , wherein the first secret sharing technique includes Shamir's secret sharing scheme.

14. 1. A hardware wallet device that provides an electronically accessible cryptocurrency wallet, comprising: a user input component configured to receive a personal identification number (PIN) sequence from a user; a removable authentication device reader configured to be physically attached to a physically attachable removable authentication device containing a stored PIN and to electrically and communicatively connect said removable authentication device to a processor; a processor configured to communicate with the removable authentication device to compare a PIN sequence with the stored PIN by the removable authentication device, the processor further configured to obtain a secret share from the removable authentication device in response to the PIN sequence matching the stored PIN; a digital storage device configured to store the secret shares obtained from the removable authentication device; wherein the processor: determining whether a number of secret shares stored on the hardware wallet device meets or exceeds a first threshold; (i) in response to the number of shares of the secret stored in the digital storage of the hardware wallet device meeting or exceeding a first threshold, applying a first secret sharing technique to the shares of the secret stored in the digital storage to recover a seed value for the hardware wallet device and storing the recovered seed value in the digital storage; (ii) in response to the number of shares of the secret stored in the digital storage device not meeting and not exceeding the first threshold, displaying a message on a user output component of the hardware wallet device instructing a user to physically attach to the hardware wallet device one or more additional removable authentication devices in electronic communication with the hardware wallet device.

15. 15. The hardware wallet device of claim 14, wherein after displaying a message on a user output component of the authentication device, the one or more additional removable authentication devices connect in electronic communication with the hardware wallet device.

16. The hardware wallet device of claim 15 , wherein the one or more additional removable authentication devices are connected in series or in series.

17. The hardware wallet device of claim 15 , wherein the one or more additional removable authentication devices are connected in parallel.

18. the user input component is configured to receive a separate personal identification number (PIN) sequence; the processor is configured to communicate with the one or more additional removable devices to compare, by the one or more additional removable devices, the another PIN sequence with a another stored PIN of the one or more additional removable authentication devices; the processor is configured to, in response to the other stored PIN matching the other PIN sequence, obtain another secret share from the removable authentication device and store the other secret share in the digital storage of the hardware wallet device; the processor determines that the number of shares of the secret stored in the digital storage of the hardware wallet device meets or exceeds the first threshold; 16. The hardware wallet device of claim 15, wherein, in response to the number of shares of the secret stored in the hardware wallet device meeting or exceeding the first threshold, the processor applies the first secret sharing technique to the shares of the secret stored in the digital storage device to recover the seed value for the hardware wallet device and stores the recovered seed value in the digital storage device.

19. 20. The hardware wallet device of claim 18, wherein the first secret sharing technique includes Shamir's secret sharing scheme.

20. and a communications device coupled to the processor, the communications device configured to notify a trusted server of the seed value recovery attempt; the trusted server is configured to send a rejection message to a user electronic messaging platform; the trusted server configured to receive a rejection message from the user electronic messaging platform; the trusted server is configured to provide the denial message to the hardware wallet device; 15. The hardware wallet device of claim 14, wherein the processor of the hardware wallet device is configured to reject recovery of a seed value in response to receiving the rejection message.

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