From: pmetzger@snark.shearson.com (Perry E. Metzger)

	You obviously haven't read the information about the system. The chips
	put out serial number infomation into the cypher stream to allow
	themselves to be identified. The system does not rely on registering
	people as owning particular phone units.

And probably as a back door to allow re-generation of the secret key.

Have we determined yet that S1 and S2 don't ever change?