Measuring Services
1KHz-11GHz
Measurement of shielding efficiency for shielded enclosures and planar materials according to IEEE 299 in the frequency range 1KHz-11GHz
10KHz- 3GHz
Power filter attenuation measurement (230Vac) according to SR EN 55017 in the frequency range
10KHz- 3GHz
The Tempest Method
1. Understanding TEMPEST
TEMPEST is rooted in the concept that electronic devices emit electromagnetic signals that can be intercepted and analysed to reconstruct processed data. These emanations, known as “compromising emanations” or “Van Eck radiation”, can be unintentional and serve as a potential security vulnerability. Adversaries with specialised equipment can pick up these signals and decipher sensitive information, including keystrokes, display content or even the entire processed data stream. Countermeasures and standards: To address the threat posed by compromising emissions, TEMPEST establishes a framework for securing electronic equipment and limiting resistance to electromagnetic radiation. The standards cover various aspects including design, installation and operational practices of equipment.
2. Shielding and filtering
TEMPEST compliant equipment is designed with shielding mechanisms to reduce fumes. This involves the use of materials that block or absorb electromagnetic radiation, such as conductive housings or special coatings. In addition, filters are used to suppress specific frequencies or harmonics that could reveal sensitive information.
3. Signal Isolation
To prevent leakage beyond the intended device, TEMPEST guidelines emphasize signal isolation techniques. This involves minimising electromagnetic coupling between different components and circuits, reducing the chances of emanations propagating to external environments where they can be intercepted.
4. Signal intensity reduction
TEMPEST sets limits for permissible levels of electromagnetic radiation emitted by electronic devices. By reducing the power of the emissions, the range over which they can be intercepted and analysed is reduced, making unauthorised interception more difficult.
5. Emission safety practices
Beyond hardware considerations, TEMPEST also emphasizes operational practices known as emissions security (EMSEC). These practices include physical security measures to restrict access to sensitive equipment, secure handling of classified information, and implementation of appropriate protocols to minimize the risk of compromise of emissions.