Portable memory device configured for host device to manage access to digital assets

1. A non-transitory computer-readable storage medium storing computer instructions, which when executed by one or more processors of a smartphone, cause the smartphone to:

detect that a memory device is inserted into a port of the smartphone,

wherein the memory device is removably coupled to the smartphone and is configured to store a particular cryptographic wallet including (1) a cryptographic key required to access a cryptographic asset and (2) a first copy of smartphone authentication information, the smartphone authentication information relating to a pairing between a Subscriber Identify Module (SIM) identifier associated with the smartphone and the memory device; and (3) configuration information stored in association with the authentication information, the configuration information comprising a predetermined timeout setting that determines a duration of time assets in the particular cryptographic wallet are inaccessible at the memory device;

cause the memory device to compare, at the memory device, the first copy of the smartphone authentication information stored at the memory device to a second copy of the smartphone authentication information received at the memory device from the smartphone;

responsive to determining, based on a comparison of the authentication information, that the smartphone is authorized to communicate with the memory device, perform a first set of operations comprising:

establish communications that enable access to the cryptographic key of the particular cryptographic wallet stored on the memory device;

access the cryptographic asset by using the cryptographic key of the particular cryptographic wallet stored on the memory device,

wherein the particular cryptographic asset is stored at the memory device, at another memory device of the smartphone, or at a blockchain network accessible by the smartphone; and

perform digital management of the cryptographic asset based on user input to the smartphone; and

responsive to determining, based on the comparison of the authentication information, that the smartphone is not authorized to communicate with the memory device, perform, by the memory device, a second set of operations comprising:

forgo establishing communications between the smartphone and the memory device;

determine, based on the configuration information, the predetermined timeout setting; and

cause the cryptographic key to be inaccessible for a period of time defined by the predetermined timeout setting.

2. The non-transitory computer-readable storage medium of claim 1 , wherein the smartphone is configured to generate, at least in part, the second copy of the smartphone authentication information by performing operations to:

assemble multiple portions of a seed phrase obtained from a set of M devices including the memory device,

wherein the multiple portions of the seed phrase are distributed across N devices, and

wherein M=N−K where K≥1.

3. The non-transitory computer-readable storage medium of claim 1 , wherein, prior to accessing the cryptographic asset, the smartphone is configured to authenticate a user based on at least one of:

a password received at the smartphone,

a facial feature recognizable by a facial recognition algorithm, or

a fingerprint feature recognizable by a fingerprint recognition algorithm.

4. The non-transitory computer-readable storage medium of claim 1 , wherein the memory device is at least one of:

a secured digital (SD) card,

an SD High-Capacity card,

an SD Extended Capacity (SDXC) card,

an SD Ultra Capacity (SDUC) card,

a Compact Flash (CF) card,

a MicroDrive (MD) card, or

a universal serial bus (USB) drive.

5. A non-volatile flash memory card for digital management of a digital asset, the flash memory card comprising:

a microcontroller; and

a memory having stored thereon a particular digital wallet including (1) a key, (2) a first copy of authentication information, the authentication information relating to a pairing between a Subscriber Identify Module (SIM) identifier associated with a particular mobile device and the memory; and (3) configuration information stored in association with the authentication information, the configuration information comprising a predetermined timeout setting that determines a duration of time assets in the particular digital wallet are inaccessible at the flash memory card,

wherein the flash memory card stores instructions which, when executed by the microcontroller, cause the flash memory card to:

compare the first copy of the authentication information to a second copy of the authentication information received from a mobile device;

determine responsive to determining, using the authentication information, that the mobile device is the particular mobile device and is authorized to communicate with the flash memory card when the flash memory card is inserted into a memory card slot of the particular mobile device, performing a first set of operations comprising:

establish communication with the mobile device; and

cause the mobile device to:

access one or more blocks on a blockchain,

 wherein the one or more blocks are referenced by the key, and

 wherein the one or more blocks store a digital asset; and

perform the digital management of the digital asset in response to receiving user input at the mobile device; and

responsive to determining that the mobile device is not authorized to communicate with the flash memory card, perform a second set of operations comprising:

forgo establishing communications between the mobile device and the flash memory card;

determine, based on the configuration information, the predetermined timeout setting; and

cause the key to be inaccessible for a period of time defined by the predetermined timeout setting.

6. The flash memory card of claim 5 , caused, as part of performing the second set of operations, to:

cause the mobile device to send a notification to a computer device associated with a user indicated by the key stored in the flash memory.

7. The flash memory card of claim 5 , wherein the flash memory card is communicatively isolated from a processor of the mobile device.

8. The flash memory card of claim 5 , wherein determining that the mobile device is authorized to communicate with the flash memory card is further based on a cryptographic password.

9. The flash memory card of claim 5 , wherein determining that the mobile device is authorized to communicate with the flash memory card is further performed using at least one of:

a password received at the mobile device,

a facial feature recognizable by a facial recognition algorithm, or

a fingerprint feature recognizable by a fingerprint recognition algorithm.

10. The flash memory card of claim 5 , wherein the authentication information further comprises a hardware identification feature specific to the mobile device, the hardware identification feature comprising at least one of a MAC address, an International Mobile Equipment Identity (IMEI) number, an International Mobile Subscriber Identity (IMSI) number, an Integrated Circuit Card Identifier (ICCID), an eSIM identifier, or a an identifier relating to a transceiver.

11. The flash memory card of claim 5 , the flash memory card being at least one of:

a secured digital (SD) card,

an SD High-Capacity card,

an SD Extended Capacity (SDXC) card,

an SD Ultra Capacity (SDUC) card,

a Compact Flash (CF) card,

a MicroDrive (MD) card, or

a universal serial bus (USB) drive.

12. The flash memory card of claim 5 , wherein the flash memory card is configured to provide an air-gapped disconnect between the digital asset on the blockchain and the mobile device.

13. The flash memory card of claim 5 :

wherein the key belongs to a digital wallet stored on the memory,

wherein access to the digital wallet is enabled based on a seed phrase including multiple terms, and

wherein portions of the seed phrase including the multiple terms are distributed across multiple computing devices.

14. The flash memory card of claim 13 configured to:

cause the mobile device to reconstruct the seed phrase based on the portions of the seed phrase obtained from fewer than the multiple computing devices.

15. A memory device for digital management of digital assets, comprising:

a non-transitory computer-readable storage medium storing: (i) a particular digital wallet including (1) a key, (2) a first copy of authentication information, the authentication information relating to a pairing between a Subscriber Identify Module (SIM) identifier associated with a particular smartphone and the memory device; and (3) configuration information stored in association with the authentication information, the configuration information comprising a predetermined timeout setting that determines a duration of time assets in the particular digital wallet are inaccessible at the memory device, and (ii) computer instructions, which when executed by one or more processors, cause the memory device to:

compare the first copy of the authentication information to a second copy of the authentication information received from a smartphone;

responsive to determining, using the authentication information, that the smartphone is the particular smartphone and is authorized to communicate with the memory device when the memory device is inserted into a receptacle of the smartphone, performing a first set of operations comprising:

establish communication with the smartphone; and

cause the smartphone to:

access one or more blockchain blocks referenced by the key and storing digital assets; and

perform the digital management of the digital assets; and

responsive to determining that the smartphone is not authorized to communicate with the memory device, perform a second set of operations comprising:

forgo establishing communications between the smartphone and the memory device;

determine, based on the configuration information, the predetermined timeout setting; and

cause the key to be inaccessible for a period of time defined by the predetermined timeout setting.

16. The memory device of claim 15 caused, as part of performing the second set of operations, to:

cause the smartphone to send a notification to a computer device associated with a user indicated by the key stored in the memory device.

17. The memory device of claim 15 , wherein the memory device is communicatively isolated from a processor of the smartphone.

18. The memory device of claim 15 :

wherein a digital wallet stored on the memory device stores the key, and

wherein access to the digital wallet is enabled based on a seed phrase that is fragmented across multiple computing devices, and

wherein the multiple computing devices includes the smartphone.

19. The memory device of claim 18 , configured to reconstruct the seed phrase based on fragments of the seed phrase stored at fewer than the multiple computing devices.

20. An apparatus for digital management of digital assets, the apparatus comprising:

a non-transitory computer-readable storage medium storing (i) a particular digital wallet including (1) a key, (2) a first copy of authentication information, the authentication information relating to a pairing between a Subscriber Identify Module (SIM) identifier associated with a particular mobile device and the apparatus; and (3) configuration information stored in association with the authentication information, the configuration information comprising a predetermined timeout setting that determines a duration of time assets in the particular digital wallet are inaccessible via the apparatus and (ii) computer instructions, which when executed by one or more processors, cause the apparatus to:

subsequent to being inserted into a mobile device,

cause an electronic display of the mobile device to display a first graphical user interface (GUI) configured to request a password from a user of the mobile device,

wherein the password is to establish communication between the mobile device and the apparatus;

compare a first copy of the authentication information to a second copy of the authentication information received at the apparatus from the mobile device; and

responsive to determining, using the authentication information, that the mobile device is the particular mobile device and is authorized to communicate with the apparatus, perform a first set of operations rising:

cause the electronic display to display a second GUI for:

 accessing one or more blockchain blocks referenced by the key,

 wherein the one or more blockchain blocks store the digital assets, and

 performing the digital management of the digital assets in response to receiving user input at the mobile device; or

 responsive to determining that the mobile device is not authorized to communicate with the apparatus, perform a second set of operations comprising:

 forgo establishing communications between the mobile device and the apparatus;

 determine, based on the configuration information, the predetermined timeout setting; and

 cause the key to be inaccessible for a period of time defined by the predetermined timeout setting.

21. The apparatus of claim 20 , configured to be inserted into, and extracted from, a memory card slot of the mobile device.

22. The apparatus of claim 20 being at least one of:

a dynamic random-access memory (DRAM) stick,

a memory card,

a secure digital (SD) card,

a flash drive,

a solid-state drive (SSD),

a magnetic hard disk drive (HDD), or

an optical disc.

23. The apparatus of claim 20 , wherein the key stored in the storage medium is encrypted to prevent an unauthorized mobile device from accessing the key when the apparatus is inserted into the unauthorized mobile device.

24. The apparatus of claim 20 caused to:

responsive to determining that the mobile device is unauthorized to communicate with the apparatus,

forgo displaying, by the electronic display, the second GUI as part of performing the second set of operations.

25. The apparatus of claim 20 :

wherein the storage medium stores a portion of a seed phrase that is fragmented into portions stored across multiple devices,

wherein the mobile device is authorized to access the key in response to the seed phrase, and

wherein the mobile device is configured to assemble the seed phrase based on some portions obtained from fewer than all the multiple devices.

26. The apparatus of claim 20 , wherein the digital assets are stored at the storage medium.