Using Protocol Obfuscation some internet protocols have tried to evade traffic shaping. BitTorrent supports Protocol Obfuscation for instance.
Is it possible to build unbreakable Protocol Obfuscation? Unbreakable in the sense that an observer cannot (heuristically) tell what kind of protocol this is?
I can think of a simple, but breakable Protocol Obfuscation scheme: Encrypt all traffic with a static pre-shared key. But traffic shaping network nodes can simply try to decrypt and identify the protocol that way.