Thursday, July 31, 2014

USB Trojan attack reports on a recently discovered gaping security hole in USB---see this link. Bugs carried on USB sticks have been implicated in many attacks, including Stuxnet, but this attack relies on modifying the USB controller's software, which is extremely difficult to detect.

Thursday, June 19, 2014

NIST CPS Public Working Group

NIST has announced the first webinar meeting of its Cyber-Physical Systems Public Working Group (CPS PWG).  More details can be found here.

Saturday, May 3, 2014

Second Edition of High Performance Embedded Computing

The second edition of my book High Performance Embedded Computing has just been published by Morgan Kaufman.  This book takes a more advanced view of embedded system design than does my other book Computers as Components. HPEC goes into detail on system architectures, design algorithms, performance analysis, energy and power.  A new chapter concentrates on cyber-physical systems. This new edition also covers thermal-aware design of embedded systems.

You can find the book's overheads and other supplements at my Web site. And you can order it from a variety of sources, including Amazon.

Thursday, April 10, 2014

More on Stuxnet

I just ran across this excellent article on Stuxnet in, of all places, Foreign Policy magazine. It contains the best technical overview of Stuxnet that I've seen so far.

Friday, March 14, 2014


I attended a meeting today on the DARPA SHIELD program where I learned a lot about the problems of assuring the integrity of electronic hardware.  Counterfeit parts are a major concern for the U. S. military and a growing concern for companies.  The SHIELD program will develop a tag with a unique ID that can be attached to all sorts of electronic components.  The tag chip will be designed to
resist efforts to examine or alter it.

Counterfeit parts are widespread and come from a variety of sources.  False designs that contain Easter eggs designed to activate at a later date and cause problem are just one of the concerns.  A lot of fake chips are recycled from old, recycled electronics; ironically, much of that recycled gear comes from U. S. consumers.  Other fakes were made by the manufacturer but didn't pass all their tests for performance, temperature, etc.  The entities that sell these chips range from mom-and-pop operations to sophisticated criminal organizations to countries.  Some of the counterfeiters just want to make money while others are intent on harming the United States.

Interestingly, DARPA thinks that some of the most serious threat comes not from the high-end components but from simpler, commodity parts.  If your Ethernet chip goes bad, it can cause just as much problems as a bad high-performance CPU.  And intermittent failures, which are common in counterfeits, are harder to debug and trace to the part causing the problem.

Electronic parts have very long, complex supply chains.   All it takes is one slip-up anywhere along that path to allow bad parts to slip into the sytsem. Paperwork on the sources of components isn't enough.  The SHIELD program could make a big change in how we think about manufacturing and using electronics.

Friday, March 7, 2014


DARPA has announced a new program on hardware assurance; here is the DARPA press release.  The SAE AS5553A standard, which we have discussed before in this blog, defines documentation procedures used to keep track of hardware provenance.  SHIELD is a much more automated approach to this problem.

The SHIELD program aims at designing a small chip that can be affixed on components.  A handheld device can then be used interrogate the device and verify that the tag identifies the proper device.   The device is designed to be cheap---less than a penny---and to be resistant to tampering.

DARPA lists several thread models that are of interest to them: recycled components sold as new; unauthorized overproduction of authorized components; substandard components sold as new; parts remarked with higher reliability or newer manufacturing dates; out-and-out copies; parts that are repackaged and destined for unauthorized applications.

Wednesday, February 5, 2014

Wall Street Journal Reports on Power Substation Attack

Today's Wall Street Journal leads with an important article on a terrorist attack on an electric power substation.  When I started to read the article, I wondered if they were describing an exercise or simulated attack.  They weren't.  A team of terrorists attacked a PG&E substation in Silicon Valley.   They cut communication lines, then used rifle shots to puncture the transformer vessels and drain them of their cooling oil.  The transformers promptly overheated.  The terrorists got away just before the police arrived.  Whoever did it was well-trained---their rifle cartridges didn't have fingerprints.

This attack is disturbing on a number of levels, of course.  One cyber-physical angle is that, although this was primarily a physical assault, they also attacked the communication links into the substation as preparation.  It appears that communication was at least close to being a single point of failure in the system.  Monitoring the status of communication clearly helps with terrorist attacks such as these and it can also help contain other types of non-malicious faults.

I commend the Wall Street Journal for bringing this event to the public's attention.