Universal serial bus device with security check

A computer-implemented method comprising:

• receiving, at an authorization server communicatively coupled to a Universal Serial Bus (USB) device, a file access request for a file between the USB device and a host;
• determining that the file access request for the file is permitted based on a hash of the file;
• generating a cryptographically signed message that allows the file to be shared with the host, wherein the cryptographically signed message is generated using an Elliptic Curve Digital Signature Algorithm (ECDSA) with a private key, a name of the file, and an indication that the file is allowed to be shared with the host, wherein the cryptographically signed message selectively enables permissions for a portion of the file, wherein the portion of the file is identified based on a starting offset and an ending offset in the file that is covered by the permissions, and wherein the permissions are selected from a group consisting of:
• read, write, and delete;
• and
• transmitting the cryptographically signed message to the USB device.

A system comprising:

• a Universal Serial Bus (USB) device comprising:
• a USB firewall configured to intercept a file access request for a file between the USB device and a host;
• a USB communication subsystem configured to transmit the file access request for the file to an authorization server and receive a cryptographically signed message from the authorization server that allows the file to be shared with the host;
• and
• a cache for storing the cryptographically signed message for a predetermined period of time;
• and
• the authorization server communicatively coupled to the USB device, wherein the authorization server is configured to determine that the file access request for the file is permitted based on a hash of the file, and wherein the authorization server is configured to generate the cryptographically signed message based on the hash of the file, wherein the cryptographically signed message is generated using an Elliptic Curve Digital Signature Algorithm (ECDSA) with a private key, a name of the file, and an indication that the file access request is permitted, wherein the cryptographically signed message selectively enables permissions for a portion of the file, wherein the portion of the file is identified based on a starting offset and an ending offset in the file that is covered by the permissions, and wherein the permissions are selected from a group consisting of:
• read, write, and delete.