Physical attacks may occur when hackers have access to the device and can exploit weaknesses of the embedded IC to steal sensitive information or to corrupt its functioning.
Leti says the shield protects chips from invasive and semi-invasive attacks by infrared lasers, focused ion beams (FIB), chemicals and other means.
Alain Merle, Leti’s security strategic marketing manager, writes:
“Implementation of multiple hardware and software countermeasures is making integrated circuits more secure, but the backside of a chip is still considered to be vulnerable to physical attacks.
“Our team designed, fabricated and tested a novel protection structure combining several elements that will trigger an alert if hackers use the backside of a chip to access the active parts of the IC.”
It consists of a metal serpentine sandwiched between two polymers, one being opaque to infrared and serving as a physical barrier against FIB attacks. It also hides the design of the chips’ serpentine and combines with the polymer underneath to detect chemical attacks.
Altering the serpentine typically triggers the IC to delete sensitive data.
The shield can also be implemented as part of standard packaging processes.
Leti’s research results will be presented at this week’s Device Packaging Conference in Fountain Hills, Arizona, in a paper entitled “Backside Shield against Physical Attacks for Secure ICs”.