External key to provide protection to devices
AssigneeHoneywell International Inc.
InventorJames L. Tucker
Life of this patent
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Abstract
An external key device including a test access port connector adapted to mate with a test access port, a test equipment connector adapted to communicatively couple to test equipment, and an external encryption chip adapted to communicate signals through the test access port to an internal encryption chip. The internal encryption chip at least one of decrypts at least one test data input from the external encryption chip based on a password shared by the external encryption chip and the internal encryption chip and encrypts at least one test data output from a protected device. The external encryption chip at least one of decrypts at least one test data output from the protected device based on the shared password and encrypts at least one test data input generated by the test equipment.
Claims20
An external key device, comprising:
- a test access port connector adapted to mate with a test access port;
- a test equipment connector adapted to communicatively couple to test equipment;
- and
- an external encryption chip adapted to communicate signals received from the test equipment connector through the test access port to an internal encryption chip,
- wherein the internal encryption chip at least one of decrypts at least one test data input from the external encryption chip based on a password shared by the external encryption chip and the internal encryption chip and encrypts at least one test data output from a protected device, and
- wherein the external encryption chip at least one of decrypts at least one test data output from the protected device based on the shared password and encrypts at least one test data input generated by the test equipment.
A system to protect a protected device and to monitor an internal system, the system comprising:
- a test access port communicatively coupled to an external encryption chip in an external key device;
- and
- an internal key device including an internal encryption chip, wherein the internal encryption chip is communicatively coupled to the protected device and the external encryption chip, and wherein test equipment is communicatively coupled to the protected device via the external key device if the internal encryption chip and the external encryption chip share at least a password.
A method to control access to an internal system and at least one protected device through a joint test access group (JTAG) port, the method comprising:
- receiving test data input generated by test equipment at an internal encryption chip via an external key device communicatively coupling the test equipment to the joint test access group (JTAG) port;
- inputting the test data input to the at least one protected device;
- receiving test data output from the protected device;
- and
- outputting the test data output to the external encryption chip via the joint test access group (JTAG) port,
- wherein the internal encryption chip at least one of decrypts at least one test data input from the external encryption chip based on a password shared by the external encryption chip and the internal encryption chip and encrypts at least one test data output from the protected device, and
- wherein the external encryption chip at least one of decrypts at least one test data output from the protected device based on the shared password and encrypts at least one test data input generated by the test equipment.
Dependencies are inferred from the claim text.