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System and Methof of Providing Tamper-Response for Exposed Low-level Contacts

IP.com Disclosure Number: IPCOM000131203D
Publication Date: 2005-Nov-09
Document File: 1 page(s) / 8K

Publishing Venue

The IP.com Prior Art Database

Abstract

FIPS 140-2 Level 3 validation requires tamper-response circuitry in a product.

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This is the abbreviated version, containing approximately 100% of the total text.

TAMPER-RESPONSE FOR EXPOSED LOW-LEVEL CONTACTS

System and Methof of Providing Tamper-Response for Exposed Low-level Contacts

Disclosed Anonymously

FIPS 140-2 Level 3 validation requires tamper-response circuitry in a product. 

This proposed solution provides tamper-response circuitry for the JTAG contacts that are accessible through the battery compartment in many of the mobile devices, providing an attacker with a low-level interface to the flash memory.

Note that if the content protection feature is not enabled, the attacker could copy and read the contents of the flash memory using the JTAG interface.

This invention provides tamper-response circuitry by modifying the JTAG circuitry so that when power is supplied to the JTAG interface (e.g. via the clock line) the flash memory is cleared, erasing all user-specific data.  The tamper-response could involve (1) supplying a surge of power to the flash memory, rendering the chip inoperable, or (2) sending a signal so that the device resets itself to the factory default setting, similar to entering an incorrect password ten times.  Note that (2) would require software modifications as well.