JTAG fuse vulnerability determination and protection using a trusted execution environment

• US 9,021,585 B1
• Filed: 03/15/2013
• Issued: 04/28/2015
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: T-Mobile Innovations LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Communications Company LP (Deutsche Telekom AG)
• Inventors: Paczkowski, Lyle W., Parsel, William M., Persson, Carl J., Schlesener, Matthew C.
• Primary Examiner(s): Zecher, Dede
• Assistant Examiner(s): AVERY, JEREMIAH L
• Application Number:
  US13/844,325
• Time in Patent Office: 774 Days
• Field of Search: None
• US Class Current: 726/22
• CPC Class Codes: G06F 21/53 by executing in a restricted environment, e.g. sandbox or secure virtual machine
• CPC Class Codes: G06F 21/577 Assessing vulnerabilities and evaluating computer system security

Abstract

A method of configuring a trusted security zone into a portable electronic device. The method comprises executing instructions on a processor of the portable electronic device that determine the state of a JTAG (JTAG) port of the portable electronic device, if the JTAG port is determined to be enabled, executing instructions on the processor preventing configuration of the trusted security zone into the portable electronic device, and if the JTAG port is determined to be disabled, configuring the trusted security zone into the portable electronic device, whereby a vulnerability to hacking the trusted security zone via an enabled JTAG port is reduced.

Claims

1. A method of configuring a trusted security zone into a portable electronic device, comprising:

executing instructions on a processor of the portable electronic device that determine the state of a Joint Test Action Group (JTAG) port of the portable electronic device;

responsive to a determination that the JTAG port is enabled, executing instructions on the processor preventing configuration of the trusted security zone into the portable electronic device;

responsive to a determination that the JTAG port is disabled, configuring the trusted security zone into the portable electronic device, wherein the trusted security zone provides hardware assisted trust, wherein configuring the trusted security zone comprises installing the trusted security zone in a secure portion of a memory in the portable electronic device; and

after the trusted security zone is configured into the portable electronic device, executing instructions on the processor creating a JTAG port inspected certificate and storing the JTAG port inspected certificate into a trusted memory area of the trusted security zone,

wherein executing instructions on the processor preventing configuration of the trusted security zone into the portable electronic device responsive to the determination that the JTAG port is enabled reduces a vulnerability to hacking the trusted security zone via the enabled JTAG port.

2. The method of claim 1, wherein determining the state of the JTAG port comprises determining whether the fuses of the JTAG port are blown.

3. The method of claim 1, wherein determining the state of the JTAG port comprises reading from the JTAG port addresses.

4. The method of claim 1, further comprising, responsive to the determination that the JTAG port is enabled, sending an electronic message to a server computer identifying the portable electronic device and indicating that the JTAG port of the device was determined to be enabled, whereby a purchaser of portable electronic devices accumulates statistical information on the performance of vendors based on the message.

5. The method of claim 1, wherein the portable electronic device is one of a mobile phone, a personal digital assistant (PDA), or a media player.

6. The method of claim 1, wherein the portable electronic device is one of a laptop computer, a tablet computer, or a notebook computer.

7. A method of protecting an electronic device from a hacking attack that exploits a Joint Test Action Group (JTAG) port of the electronic device that has not been disabled, comprising:

executing instructions on a processor of the electronic device that determine the state of a JTAG port of the electronic device;

responsive to a determination that the JTAG port is enabled, executing instructions on the processor of the electronic device to detect a physical connection to the JTAG port;

responsive to detecting a physical connection to the JTAG port, executing instructions on the processor preventing execution of trusted applications;

responsive to a determination that the JTAG port is enabled, executing instructions on the processor preventing execution of software that reads from the JTAG port; and

responsive to a determination that the JTAG port is enabled, preventing downloading of at least one of confidential information, financial applications, a credit card number, or a credit card payment application,

wherein executing instructions on the processor preventing execution of the trusted applications responsive to detecting the physical connection to the JTAG port, executing instructions on the processor preventing execution of the software that reads from the JTAG port responsive to the determination that the JTAG port is enabled, and preventing downloading of at least one of confidential information, financial applications, a credit card number, or a credit card payment application responsive to the determination that the JTAG port is enabled reduces a vulnerability of the electronic device to a hacking attack that exploits the enabled JTAG.

8. The method of claim 7, wherein the electronic device is one of a mobile phone, a laptop computer, a tablet computer, a notebook computer, a server computer, a router, or an embedded system.

9. The method of claim 7, wherein determining the state of the JTAG port comprises reading from addresses associated with the JTAG port.

10. The method of claim 7, wherein determining the state of the JTAG port comprises determining the state of JTAG fuses.

11. The method of claim 10, wherein responsive to a determination that the JTAG fuses are intact, storing a parameter value abstractly indicating that the JTAG port is enabled.

12. The method of claim 10, wherein responsive to a determination that the JTAG fuses are blown, storing a parameter value abstractly indicating that the JTAG port is disabled.

13. The method of claim 7, further comprising sending a message to a server computer indicating that the JTAG port is not disabled.

14. A method of thwarting a hacking attack on a mobile phone via an enabled Joint Test Action Group (JTAG) port of the mobile phone, comprising:

executing instructions on a processor of the mobile phone that detect the state of the JTAG port as one of enabled or disabled;

responsive to a determination that the JTAG port is enabled, taking a first action to reduce vulnerability to hacking attacks via the enabled JTAG port, wherein the first action comprises preventing downloading of at least one of confidential information, financial applications, a credit card number, or a credit card payment application;

responsive to a determination that the JTAG port is disabled, configuring a trusted security zone into the mobile phone, wherein configuring the trusted security zone comprises installing the trusted security zone in a secure portion of a memory in the mobile phone; and

after the trusted security zone is configured into the mobile phone, executing instructions on the processor creating a JTAG port inspected certificate and storing the JTAG port inspected certificate into a trusted memory area of the trusted security zone.

15. The method of claim 14, further comprising when the JTAG port is determined to be enabled, marking a hardware portion of the mobile phone intended for installation of a trusted security zone as one of invalid or untrusted.