[peterclary]

Once created, what stops the Government from obtaining a copy of the modified OS and the means to sign/encrypt it for any device? Either via some top-secret "You can't tell anyone about this or you go to jail" process, or via an agent embedded in the company?

[icebraining]

What stops them from using those mechanisms to create it in the first place?

[rhizome]

Knowledge and skill, evidently.