Soft Tempest: Hidden Data Transmission Using Electromagnetic Emanations

It is well known that eavesdroppers can reconstruct video screen content from radio frequency emanations. We discuss techniques that enable the software on a computer to control the electromagnetic radiation it transmits. This can be used for both attack and defence. To attack a system, malicious code can encode stolen information in the machine's RF emissions and optimise them for some combination of reception range, receiver cost and covertness. To defend a system, a trusted screen driver can display sensitive information using fonts which minimise the energy of these emissions. There is also an interesting potential application to software copyright protection.

• Type: Conference
• Year: 1998
• Where: IH
• Authors: Markus G. Kuhn, Ross J. Anderson
• Keywords: IH 1998, Information Management, Machine's Rf Emissions, Radio Frequency Emanations, Video Screen Content