Need to know basis - Tradução em português

Disclosure and dissemination to the receiver's employees shall only be made on a strict need to know basis = Divulgação e disseminação para os funcionários do receptor devem ser feitas apenas numa estrita política de restrição de acesso.

The term "need to know", when used by government and other organizations (particularly those related to the military or espionage), describes the restriction of data which is considered very sensitive. Under need-to-know restrictions, even if one has all the necessary official approvals (such as a security clearance) to access certain information, one would not be given access to such information, or read into a clandestine operation, unless one has a specific need to know; that is, access to the information must be necessary for the conduct of one's official duties.

That's the best I could do.

Cheers!

I think I can fit 'política de restrição de acesso' in my text. It's better than my original translation. Thanks!
But what I was wondering was whether there is a fixed expression in Portuguese... something everyone uses, but I can't think of anything.