Grok/ZTK security is both too complex, and too slow. At the bottom is the general zope.security model. On top of that is the
zope.securitypolicy model. On top of that is the Zopache security model. Way way too much.
Worse yet, the three are quite different. The user model is to click check boxes to assign permissions to roles, and roles to users.
Everything else are unneeded concepts.
I invite you to Register and then link to your own blog postings and