karsh@geowhiz.UUCP (Bruce Karsh) (11/13/85)
I recently was playing with a terminal and an oscilloscope, trying
to get the terminal working and interfaced to our system. I noticed
that when I just held the scope probe next to the RS-232 cable, I
could see the serial data going by on the scope.
Is it possible to non-intrusively tap a serial line like this?
Would shielded twisted pair serial lines be safer? Can you tap
an Ethernet like this?
--
Bruce Karsh
U. Wisc. Dept. Geology and Geophysics
1215 W Dayton, Madison, WI 53706
(608) 262-1697
{ihnp4,seismo}!uwvax!geowhiz!karshdennis@rlgvax.UUCP (Dennis Bednar) (11/14/85)
> > I recently was playing with a terminal and an oscilloscope, trying > to get the terminal working and interfaced to our system. I noticed > that when I just held the scope probe next to the RS-232 cable, I > could see the serial data going by on the scope. > > Is it possible to non-intrusively tap a serial line like this? I once read somewhere that someone with the proper equipment in a different room, can tap into the data-stream between your terminal and host, but I don't know how true it is. Given sensitive enough equipment, I would believe this. Anyway, DOD has recognized that emination of electrical radiation from computer type devices can be bad (allow intruders to snoop on their data), and so has come up with the "Tempest" standard, which basically says that a device must be manufactured such that the radiation is minimized from leaking out. -- Dennis Bednar Computer Consoles Inc. Reston VA 703-648-3300 {decvax,ihnp4,harpo,allegra}!seismo!rlgvax!dennis