Counterfeit-proofing chips with digital fingerprints
As any reader of detective fiction will tell you, no two fingerprints are alike. The similarly unique physical structure of microchips could help manufacturers protect their products from piracy, thanks to research at the Fraunhofer Institute for Secure Information Technology. The team has developed technology that makes use of slight variations generated during manufacture to produce unique, clone-proof digital fingerprints.
Product piracy is not the exclusive domain of consumer electronics, but can also hit industry hard. According to the German Engineering Federation, such activity has cost Germany's mechanical and plant engineering sector over EUR 6 billion (over US$8 billion) in 2010. While manufacturers can suffer further losses due to the damage caused by low quality counterfeit products, people's lives could also be put at risk.
Simply trying to protect product and component designs with patents and confidentiality agreements has had only limited effect against the pirates and, although there are commercially-available anti-piracy technology solutions available, any counterfeiter worth his salt won't let such trifling obstacles get in the way of making a fast buck from cheap copies.
Progress with PUF
Researchers from the Fraunhofer Institute, located in Garching near Munich, say that electronic components or microchips can be made counterfeit-proof using physical unclonable functions (PUF). Slight variations in thickness, length or density that occur during component manufacture, but which don't affect functionality, can be used to generate a unique digital identification key.
The Fraunhofer researchers have developed a measuring circuit prototype using a ring oscillator PUF. "This oscillator generates a characteristic clock signal which allows the chip's precise material properties to be determined," said Fraunhofer's Dominik Merli. "Special electronic circuits then read these measurement data and generate the component-specific key from the data."
Unlike typical cryptographic processes, the unique digital key is not stored in the device itself so cannot be uncovered by the use of scanning electron microscopes, focused ion beams or laser bolts. Any attempt to attack the chip would result in the physical structure being altered or destroyed, making it virtually impossible to produce a functioning clone.
Showing off the prototypes
The ring oscillator PUF has been successfully integrated into a field programmable gate array that can generate a coded key, and the researchers say that this could "allow attack-resistant security solutions to be rolled out in embedded systems."
The team has also created a butterfly PUF prototype and will present both developments at the Embedded World Exhibition & Conference in Nuremberg from March 1 to 3.