Well, the thing about the internet is that it's completely open: implementers work off of specifications. If you're curious what sort of back doors might be in

Well, the thing about the internet is that it's completely open: implementers work off of specifications. If you're curious what sort of back doors might be in the specifications, you can read them all at ietf.org (although there are a lot of them). How they're implemented varies from one implementation to the next, but they _have_ to follow the specification, or else they won't be compatible with other implementations, leaving little room for "secret" back doors in the specifications themselves.