I-D Nits complains that the introduction and abstract should indicate that this I-D updates RFC 5652.

Yeah this is a nit:

In s2, should this:
The originator establishes the CEK using these steps:
be replaced by this:
The originator establishes the CEK (or CAEK) using these steps:
because the processing overview addresses both (see s1).
Actually do the "or CEAK" in the rest of the section too? See:
https://github.com/lamps-wg/cms-kemri/pull/11