I got the opportunity to present our recent research on emission image analysis at IEEE HOST this year. I ended up receiving the best student presentation award for my talk at the conference, for which I would like to thank all of the conference organizers. For me this was completely unexpected, but, for whatever its worth, attendees told me in subsequent conversations that I was the only one who didn't do a 30 minute lecture - and that's what I like to hear.
HOST is a fairly short two day conference, but definitely worth looking at if you work in the area of HW security research. It is one of the few conferences which really does focus on hardware security. HOST has been collocated with DAC for at least two years now. This is notable if you do IC design since you get to go yell at the vendors (Mentor, Cadence...) that cause you to spend hours in front of your computer screen tearing your hair out. Some would call this closure.
Our Paper - Functional IC Analysis
So at HOST, we presented our research about how emission images can be used to identify points of interest on the chip. A couple of years back, Sergey Skorobogatov pioneered some of these techniques and demonstrated them for a programmpable PIC microcontroller. In this work, we demonstrate how these techniques can be used to essentially fully reverse engineer the IC. By executing different subroutines on the IC and computing difference images between two or more images one can quickly and easily identify relevant registers on the IC. This is something which is extremely useful for subsequent attacks, like laser fault injection. Also it can reveal static memory contents and other important information about the program running on the chip.
We will be releasing some of the images and "videos" or "time lapses" very soon, so stay tuned. I will also be presenting some of this work at ReCON and going into more detail about how this can be abused on real chips. So check me out there! Also you can take a look at the paper here.
Other notable research
I felt I should mention a couple of works that stood out in my mind that readers might want to consider taking a look at.
UNM presented their research "Bit String Analysis of Physical Unclonable Functions based on Resistance Variations in Metals and Transistors". They were able to generate almost obscene amounts of bits with a clever PUF scheme in which they perform measurements across metal wires of the IC. This is possible because of how simple the read out circuitry is. All in all, an interesting alternative to the SRAM based PUFs, which were common for other implementations presented at the conference. However, this approach doesn't seem like one which can be easily included in a standard cell design, but the sheer amount of bits generated per IC are nevertheless very impressive.
My colleague and buddy, Clemems Helfmeier, from the Semiconductor Devices research group at TU Berlin presented his implementation of a FIB sensor. The work, entitled "On Charge Sensors for FIB Attack Detection", describes how an antenna can be used to detect FIB navigation. Subsequently the charge can be stored in a floating gate, which can provide this information to the IC during the next power-up. Since the antenna gathers enough charge solely from the ion beam during navigation, the device does not have to be powered to detect the navigation of the FIB.
Verayo also had a very nice presentation about their ongoing PUF research entitled, "Performance Metrics and Empirical Results of a PUF Cryptographic Key Generation ASIC". Their implementations could be synthesized in standard cells, which of course is particularly important in a fabless world. This research received the best student paper award.
Panel Discussion - Counterfeit Parts
There was a great panel discussion, which opened up my eyes to the issue of counterfeit parts in today's global supply chain. The panel highlighted the breadth of counterfeits in US supply chains. The panel also provided concrete examples of functional counterfeits, counterfeits with older die revisions, refurbished parts and lower specced parts. As the panel pointed out, die markings on modern counterfeits can be so good that they can even fool the manufacturer. The panel also highlighted how this continues to be an unresolved issue for the industry. Besides visual inspection and comprehensive electrical tests there is very little that can be done efficiently within the supply chain. Not to mention that the the underlying assumption was that you can not test more than a couple of devices per lot. In any case, a very intriguing topic and one in which there is still a lot of opportunity to come up with better solutions.
Links
And here's a couple of links to stories that I came across, which I wasn't completely familiar with before the conference.