Re: [PEN-TEST] How secure is an ISDN line? Fibre Optic TAPs

[Carson Gaspar <carson () taltos org>]

--On Tuesday, October 24, 2000 4:36 PM -0500 Peter Gamache <peter () LUNO ORG>
wrote:

> I've only had one client who cared about fiberoptic security (it's
> outside the reach of most folks these days, and they didn't understand
> that their competitors aren't 14-year-olds with 486's) - and I advised
> them of a very simple tactic: Put the fiber within a metal pipe, then
> fill the pipe with air, under pressure.  Once the pressure is applied and
> the pipe sealed, a pressure sensor at either end can easily tell you of a
> physical security breach.  I thought of this after the installation, but
> an even better idea (to prevent rust within the pipe) is to pressurise
> the pipe with pure nitrogen gas instead of air.
>
> Can anyone see a way to get past the nitrogen/pressure sensor defense?

Yup. It's fairly simple to work on a pipe without significantly altering
the pressure - either by using a good sealant, or by enclosing the area
being worked on in a pressurized environment. Of course, this does raise
the bar to how advanced your attacker has to be.

BTW: you _can_ tap fiber without cutting & splicing it. I'm not enough of a
spook to remember the details off the top of my head, but I'm sure someone
on cypherpunks would be happy to elucidate.

--
Carson Gaspar -- carson () taltos org
Queen Trapped in a Butch Body