Researchers hack computer keyboards

Date:   Wednesday , November 05, 2008

Now the wired keyboards you use can be hacked. The key strokes of wired keyboards can be recovered by simply measuring the electromagnetic radiations emitted when keys are used, says a Swiss research team.

In a paper for the Lausanne Security and Cryptography Laboratory, researchers Martin Vuagnoux and Sylvain Pasini have demonstrated that certain keyboards, particularly the modern ones, contain enough electronic components that can be spied from a distance to reveal what is being typed. To analyze compromising radiations, the team used a receiver tuned at a specific frequency.

“We conclude that wired computer keyboards sold in the stores generate compromising emanations (mainly because of the cost pressures in the design),” says the team.

The team found four different modes of attack that could be used to capture keystrokes from up to 20 meters away, even through walls. They tested 11 different keyboard models including laptop, USB, and PS2 types that were purchased between 2001 and 2008. All were found to be vulnerable to at least one of the four attacks. They used basic, inexpensive equipment yet in one demonstration managed to capture keystrokes inconspicuously from an adjacent room. To ensure the success of the experiments, they removed all other sources of interference ? the display and computer's power supply, which would not be possible in a real-world setting. The team is confident, that the system could be improved with more sophisticated equipment.

The findings, which will be published, conclude that the cheap keyboards are not safe as they can’t be used to pass sensitive information. Given the risks of wireless keyboards, which require even less sophistication to intercept, it appears there is no safe way to enter sensitive information into a computer, apart from Tempest-protected equipment as described by various national communication security information memorandums. Tempest is a code name used by the government to refer to a program to secure electronic devices from leaking information in the form of radio frequency waves, or electronic emanations. Some security researchers see Tempest as an acronym that stands for "TEMPorary Emanation and Spurious Transmission, while others offer alternative interpretations.