MIT Technology Review: In 2011, General Michael Hayden, who had earlier been director of both the National Security Agency and the Central Intelligence Agency, described the idea of computer hardware with hidden “backdoors” planted by an enemy as “the problem from hell.” This month, news reports based on leaked documents said that the NSA itself has used that tactic, working with U.S. companies to insert secret backdoors into chips and other hardware to aid its surveillance efforts.

That revelation particularly concerned security experts because Hayden’s assessment is widely held to be true. Compromised hardware is difficult, and often impossible, to detect. Hardware can do things such as access data in ways invisible to the software on a computer, even security software. The possibility that computer hardware in use around the world might be littered with NSA backdoors raises the prospect that other nations’ agencies are doing the same thing, or that groups other than the NSA might find and exploit the NSA’s backdoors. Critics of the NSA say the untraceable nature of hardware flaws, and the potential for building them into many systems, also increases the risk that intelligence agencies that place them will be tempted to exceed legal restrictions on surveillance.

“Hardware is like a public good because everybody has to rely on it,” says Simha Sethumadhavan, an associate professor at Columbia University who researches ways to detect backdoors in computer chips. “If hardware is compromised in some way, you lose security in a very fundamental way.” [Continue reading…]