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

[Talisker <Talisker () NETWORKINTRUSION CO UK>]

Just to clarify

I didn't write

> > "OC-# - OC-1,2-48 etc.. Any fiber optic medium is going to require you
to
> > split the fiber itself at some point and redirect the signal into a
third
> > party tap. From there you will once again have to reconstruct the data
> > stream from the multiplexed/frame encapsulated data within.. this
applies to
> > almost any type of carrier."

I commented on what was written, because I disagreed with it, but cut and
pasted without the reply markers

Andy
http://www.networkintrusion.co.uk Talisker's comprehensive IDS & Scanner
List
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----- Original Message -----
From: "Peter Gamache" <peter () LUNO ORG>
To: <PEN-TEST () SECURITYFOCUS COM>
Sent: Tuesday, October 24, 2000 10:36 PM
Subject: Re: [PEN-TEST] How secure is an ISDN line? Fibre Optic TAPs


> "van der Kooij, Hugo" wrote:
>
> > On Tue, 24 Oct 2000, Talisker wrote:
> >
> > > "OC-# - OC-1,2-48 etc.. Any fiber optic medium is going to require you
to
> > > split the fiber itself at some point and redirect the signal into a
third
> > > party tap. From there you will once again have to reconstruct the data
> > > stream from the multiplexed/frame encapsulated data within.. this
applies to
> > > almost any type of carrier."
> >
> > I just saw some mentioning of using quantum level signaling to prevent
> > taps. As at this level you can't inspect a signal without altering it.
So
> > a good CRC check would notice tampering with the transmission.
>
> 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?
>
> - Peter