[ietf-dkim] on the scope and necessity of threat analysis

[Hallam-Baker, Phillip]

Just make a cogent statement of the problems that DKIM is attempting to
solve that would not exist if DKIM did not exist.

There are two threat analyses possible:

	Report = Threats (World)

	Report = Threats (World + DKIM)

To get chartered the group needs to show

	Threats (World + DKIM) < Threats (World)

If you take my advice on the charter this is much easier to do.