Two researchers claim to have developed techniques for sniffing electromagnetic emanations from wired keyboards, allowing them to detect keystrokes over a few metres with no attachment to the vulnerable device.
Martin Vuagnoux and Sylvain Pasini, doctoral researchers from the security and cryptography laboratory at the École Polytechnique Fédérale de Lausanne (EPFL), claim the sniffing techniques could compromise keystrokes and passwords.
"Wired keyboards emit electromagnetic waves, because they contain electronic components," wrote the researchers in a blog post. "[This] eletromagnetic [sic] radiation could reveal sensitive information such as keystrokes."
The researchers posted two videos they claim show their sniffing techniques in action. The first video purportedly shows a one-metre piece of wire, used as an antenna, hooked into an oscilloscope. A researcher taps "trust no one" into a keyboard that is linked to a laptop, the signal is supposedly sniffed, and the words recreated on a remote screen. In the video, the researchers apparently show that an LCD screen and PC have to be removed to stop interference in the transmission of the electromagnetic radiation from the keyboard.
A second video purportedly shows the same hack, but using a more powerful antenna to sniff the signal through a wall.
The researchers have not published technical details of the supposed hack, and said they were waiting for their research paper to be peer reviewed.