Subject: [mobile-ip] Security requirements clarification

From: Michael Thomas <[email-masked]>
Date: Tue, 24 Jul 2001 11:41:57 -0700 (PDT)

One thing that I think we need to clarify in the
security requirements draft is the relationship of
strong authentication crypto based security to
this draft. The draft rightly rejects the notion
of a global PKI-like scheme, but this leaves the
impression that _any_ PKI/strong crypto based
solution doesn't meet requirements. Or at least
it leaves that taste in my mouth.

What would be better is lay down requirements for
a strong crypto based solution as well as a weaker
version which doesn't run afoul of the global PKI
problem. Something like:

1) The security solution MUST provide a method to
   secure binding messages using conventional
   strong cryptographic authentication which can
   leverage existing authentication infrastructures.
   This aspect of the solution MUST provide
   message integrity and privacy. The solution
   MUST apply to both the MN/HA and MN/CN communication.

2) The security solution MUST NOT require that the
   authentication infrastructure be extended to
   global proportions. As such, a solution which
   doesn't rely on strong authentication is
   acceptible so long as the difficulty is on
   the order of guessing a very large random
   number (ie requirement #1 in 7.2)
   [perhaps controversial:] This method MUST
   NOT be used for MN/HA communication.

	  Mike