You have your answer, but I'll add some background anyway. TEMPEST is old stuff (US/UK). Anyone who's ever worked in COMSEC (Government Communications Security) knows about TEMPEST, it was a big deal during the cold war. Most of the basic stuff was declassified in 1995.
It's simply the ability to block any and all unintentional signals ('electro-magnetic radiation') which may emanate from communication or data processing equipment. There's two parts of COMSEC equipment, the part than handles the plain text data like I/O, processor and memory (red side), and the part that's not involved in unencrypted data like power supplies and I/O that carries encrypted data (black side). One of the earlier examples of a TEMPEST leak was the ability to pick up typed text from the power lines into teletype equipment or even the IBM Selectric typewriters. Some of the embassies on both sides of the cold war were found to have innocent wires stretched across the ceiling of the comm center but with both ends unterminated, which apparently operated as a simplistic amplifier or pickup. Many bugs picked up and repeated electronic, not audio signals. The U.S. Embassy in the USSR had to be rebuilt in the '80s because the concrete was peppered with passive electronic components (things like resistors and real bugs). A simple demonstration of TEMPEST vulnerability is by using a telco impedance pickup. The impedance pickup will amplify voice (or data) on a phone wire without needing to touch the metal wire. It picks up the varying magnetic field around a wire which expands and collapses as the signal changes. (It also buzzes radically when near fluorescent bulbs, old high-leakage CRT monitors, some LCDs, some keyboards, and some mice). Another related term you might want to google is SIGINT, or Signals Intelligence. It covers the ability to collect, and process, signals. There's more to it than meets the eye. The position of a signal can be triangulated electronically within a few milliseconds, 'position' is data. The keystrokes or other characteristics of encrypted data can tell you who the operator is, 'characteristic' is data you can link with HUMINT (Human Intelligence). Then there's the conversation, sorta tells you who's talking to who and what's been escalated up to or repeated from headquarters (makes life easy if someone in the conversation passes along a message using weak crypto or a compromised key). Many INTEL satellites are SIGINT, more like radioscopes pointed down which join the hubble-sister telescopes pointed down. (Note: Encryption applies privacy only temporarily. Encryptions of the past are obsolete and weak today, and can be decrypted at leisure.) That's what TEMPEST is worried about. Leaking signal from red side to black side, that signal getting picked up by some guy with telco gear, a bug in the wall or an antenna in the ceiling, or a trio of satellites above. Doesn't help you used that 3DES PGP key 5 years ago. Bill Stout -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Sebastian Ziegler Sent: Friday, August 18, 2006 9:45 AM To: full-disclosure Subject: [Full-disclosure] Tempest today -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hi list, I've seen some fuss about the technique called "tempest" lately. Some people claim it would be "the thing" in modern security. This bugs me somehow because first of all I think it is way to much of an effort compared to the more casual techniques used today. Also all information that I can find on the Internet refers to some stuff the NSA released in the mid-nineties. Now that is not really a good and reliable source of information in my believe. :) Can anybody tell me how far evolved this technique is today and who uses it? Maybe some reference to a whitepaper or something similar. Would be great. Thanks Paul Brief definition of tempest for those who have never heard of it: Picking up the radiation produced by a monitor or cables that connect the graphics-card or graphics-chipset with the monitor in order to spy the screen of the user. Kind of like getting access to a VNC server on the box without having input yourself. The interesting part is that it is technically undetectable. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFE5e6XaHrXRd80sY8RCg/9AKCBAs2SjvitArRFHs+6moRb0UX4GQCfbCo9 wi9z1V+h5m0YJFdz9IZK+EI= =2pu2 -----END PGP SIGNATURE----- _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/ _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/