Advanced encryption standard to provide hardware key interface
AssigneeHoneywell International Inc.
InventorJames Tucker
Life of this patent
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Abstract
A system to control access to at least one protected device, the system comprising a test access port operable to mate with an external key device and an internal key device that is operable to receive synchronized cipher words during an idle state of the test access port from a removable external key device. The internal key device is also operable to receive test signals via the external key device and to input the received test signals to the protected device based on the synchronized cipher words. The protected device and the internal key device are one of located within a closed chassis, located under a protective security coating, located within a multi-chip-module, located within a closed integrated circuit package, and combinations thereof.
Claims24
A system to control access to at least one protected device, the system comprising:
- a test access port operable to mate with an external key device;
- and
- an internal key device operable to receive synchronized cipher words during an idle state of the test access port from a removable external key device, operable to receive test signals via the external key device and operable to input the received test signals to the protected device based on the synchronized cipher words, and wherein the protected device and the internal key device are one of located within a closed chassis, located under a protective security coating, located within a multi-chip-module, located within a closed integrated circuit package, and combinations thereof.
A method to control access to at least one protected device through a test access port, the method comprising:
- initiating synchronization of cipher words by communicating a synchronization initiating sequence of data to an internal key device via the test access port;
- receiving a random word from an internal key device responsive to the synchronization initiating sequence of data;
- generating synchronized cipher words at an external key device responsive to receiving the random word;
- communicating a current cipher word to the internal key device when a test data input connection of the test access port is idle;
- communicating test-request data to the internal key device;
- and
- receiving test-results data communicated from the protected device via the internal key device during one of a shift-IR state or a shift-DR state responsive to communicating the cipher word and the test-request data.
A method to control access to at least one protected device through a joint test access group (JTAG) test access port, the method comprising:
- initiating a challenge at an internal key device;
- receiving a response to the challenge from an external key device;
- and
- granting access to the protected device via the joint test access group (JTAG) test access port based on the received response,
- wherein initiating the challenge comprises:
- generating a random word at the internal key device;
- generating synchronized cipher words at the internal key device responsive to generating the random word;
- communicating the random word to the external key device;
- and
- generating synchronized cipher words at the external key responsive to receiving the random word;
- wherein receiving the response to the challenge comprises:
- receiving the cipher word generated by the external key device when a test data input connection of a joint test access group (JTAG) test access port is idle;
- and
- determining the cipher word is authentic wherein access is granted to the protected device based on the authentic cipher word.
A program product comprising program instructions, embodied on a storage medium, that are operable to cause a programmable processor to:
- synchronize a generation of cipher words responsive to receiving an initializing sequence and based on a generated random word and a secret password shared with an external key device;
- transmit a test-request data to a protected device responsive to the synchronized cipher words;
- and
- communicate test-results data to the external key device.
A system to protect a device from unauthorized access, the system comprising:
- means to use a key exchange protocol to determine if test equipment is authorized to access a protected device;
- means to receive test-results data from the protected device at an internal key device;
- means to encrypt the test-results data;
- and
- means to communicate the encrypted test-results data to an external key device base on the determination.
Dependencies are inferred from the claim text.