According to the latest report, which is a joint effort of European and American specialists, CPUs used in computers can be equipped with a hardware Trojan horse. Already at the stage of their production, the design of the system can be changed to include the appropriate technology to facilitate the break-in of computers and the spying of users of such equipment. Worse yet, these changes would be virtually undetectable without the use of specialized equipment.
The above message should not be a big surprise. Five years ago, researchers from the University of Illinois at Urbana-Champaign have proven that it is possible. By adding a few additional items to the chip, they can spy on the user without hindrance.
Recent research in this field shows, however, that the proper fabrication of the system does not require the installation of any additional circuitry, as it can simply change the doping of some transistors.
This is a method to introduce impurities into the silicon to thereby change its electrical properties. By adjusting the doping of a small number of transistors you can modify the operation of the system to create a hardware spy directly in the processor. And since the changes were made at the atomic level, they can not be detected using standard IC quality verification methods.
You could write that the NSA would be happy to welcome new ways of spying on citizens, but I am surprised that they have known this for a long time, and perhaps even use this knowledge on a large scale. All the more, as I recently wrote, NSA can hack into virtually any computer, and so modified processor would make it much easier.