RÖS and TEMPEST stand for revealing signals. RÖS is a Swedish name and TEMPEST is an International name.

Disclosure signals occur when information is transmitted unintentionally, as all electronic equipment generates electromagnetic radiation that can be intercepted and read.

Disclosure signals are those signals, electromagnetic, acoustic and / or optical signals, which leave a device / system unintentionally and which can be detected and analyzed in order to obtain confidential information which is handled in the device / system.

Historically, RÖS / TEMPEST protection has mainly been used in Defense-related industry, but there are also many civilian activities that need to take measures to protect themselves against RÖS (Industrial espionage, etc.).


It is not possible to equate the Swedish RÖS requirements with the international TEMPEST requirements. To a large extent, they have the same purpose but handle the problem of revealing signals in different ways. In some cases, the RÖS requirements can be met with TEMPEST equipment. The word TEMPEST means nothing in itself but is a remnant of the time when revealing signals was a relatively new area and was given the code name TEMPEST.

Benefits of the TEMPEST regulations

  • TEMPEST means you get one faster
  • management process when choosing IT equipment as you can start from the usual COTS products. Greater access to market products and solutions (simple expressed: “everything that goes on electricity”) 
  • Lower price
  • TEMPEST is an international norm in contrastagainst RÖS, which is national, which is important for exports and international cooperation. 
  • In the next few years, Swedish military Alliances increasingly cooperate with other nations' defense forces. This means that Swedish systems must meet both Swedish requirements and International requirements. This requires an increasing awareness of disclosure signals and then above all requirements according to TEMPEST standards.

Challenges with the TEMPEST regulations

There are also some challenges in implementing the TEMPEST acquis:
There are three so-called national regulations in our national regulations
equipment classes; U1, U2 and U3 which indicates how far an equipment
rays. Correspondingly, TEMPEST-measured material is divided into classes; A, B
and C.
  • The classes that radiate the least, U1 and A, respectively, differs relatively much with respect to radiated distance where U1 has it shorter distance. This means that for signal protection systems intended for SG S or higher and certain Class A equipment placed in particularly exposed locations, must be given supplementary protection to correspond to current U1 equipment. 
  • Requirement that installation takes place in accordance with the regulations initially entails an increased cost as corresponding requirements do not exist in ours now current regulations, however, it is estimated that IT equipment will be sold in one faster pace than buildings, premises, combat vehicles, ships, aircraft etc. 
  • One can e.g. easy to believe that crypto- and IT systems that have the highest degree of protection against revealing signals (U1), in it national regulations, can be placed arbitrarily, but it is a wrong assessment as this type of system must also have a certain separation from among other open systems and radio transmitters.

2makeIT expertise in RÖS / TEMPEST

We have extensive experience in developing RÖS / TEMPEST solutions.
Feel free to contact us if you need more information, training within TEMPEST and / or requirements for approved safety functions (KSF).