re tempest in article apr lynx dac northeastern edu angel foghorn leghorn coe northeastern edu writes i heard somewhere can t name the source that tempest does not necessarily pick up just crts but it can pick up emissions from almost any chip if that is true the kind monitor would not make any difference becuase everything on the screen can be picked up from the video controller can anybody verify or refute this you are correct several times tempest is a codeword for a standard shared between the nato governments to limit the inadvertent emission of information by either electromagnetic radiation or conduction the limits set in the standard are classified but there is open source information to the effect that either the electrical or magnetic components of electromagnetism can be exploited it is a basic rule of physics that there is an electromagnetic field associated with any path that conducts a flow of electrons among other things i drive a korean built at clone and an associated pin dotmatrix printer the major source of unintentional emission is the crt to that can be added the video driver card the rs parallel cable and the printer head the emissions from these are gross can be detected with the crudest of equipment were i to apply good test equipment and some intelligence to measuring emission levels i would find many other potential sources of leaked information where cryptography is used for serious purposes poor tempest protection becomes an important security hazard in the early eighties the need to allow some commercial concerns particularly financial institutions a level of protection against tempest threat led to a series of briefings to invited corporations and to the release of a cut down tempest stansard for commercial use i say release for while equipment to meet the standard is available at a price and to approved customers afaik even the commercial standard remains classified if you think about it it would really have to wouldn t it owen lewis tele fax eloka consultancy project management oml eloka demon co uk pgp x public key on request
