Biztalk and ESB Security – does it exist?

Hi,

I have been wandering around for security guidance on Biztalk and ESB…  but no luck as of yet.  Is it because ESB and security are far apart each other?

The main issue I encounter is how I can efficiently carry an identity, say from a WCF receive port, apply a form of habiliation on this identity to make sure it doesn’t mess around with data or orchestrations it doesn’t have to play with, and gracefully go off-ramp through another WCF port…

Is this too obvious that I cannot figure it out or is this unfeasable?