Security level

None : (Authentication only) The header of each request and response is signed. You know who sent you this thing but you don't really know for sure what's in it.
Integrity : The header and body of each request and response is signed. So you know who sent this thing and what was in it.
Privacy : The header of each request is signed, and the body is encrypted, so you know everything you knew with krb5i, but everyone else knows less.