Hi Anders,
I now realize the linkage between the components of compound
assertions is more secure than I had thought. As you pointed out,
if a URI appears in the <DependsOn> element, then the object to which
the link refers must have the same URI embedded in its <ID> element.
Both objects must have valid signatures.
I think this makes the security of the linkage between compound
assertions independent of external components such as DNS, which
is what I was worried about.
I had misunderstood the intended relationship between the <ID> and
<DependsOn> element.
Thanks and regards,
Nigel.