The NSA should be split in three, similar to what they did to MaBell.
One part would be pure R&D
The Second part should be Apps to help their spying and data collection for foreign purposes (What they usually do today)
The Third part should be Apps to defend the country from someone else using apps similar to those used by the Second Part against USA.
The Second and Third part should have a real Chinesse wall, never talking, never knowing what each one is doing.
It is the only way we could trust again whatever help the Third Part provides to cryptographic standards and stuff like SELINUX. Likewise, the Third Part should work in the open in a as transparent way as possible.