Clipper and Traffic Analysis

[smb at research.att.com]

	 >Does anyone here have any thoughts as to whether Clipper enables traf
	fic
	 >analysis or tracing more easy than it normally is under Switching Sys
	tem
	 >7? 

	 SS7 uses out-of-band signalling.  The clipper LEAF is an in-band
	 signal.  Therefore a tap for clipper yields two kinds of information,
	 content and identities.

	 Tapping an SS7 signalling network is more expensive and more difficult
	 to justify.  More expensive because it runs packet-switched, more
	 difficult because it's not the conversation of any particular party
	 except the phone company.

Also, it probably goes via a different physical path.  And at least some
SS7 trunks are encrypted with DES.