Add messaging protocol that is resistant to traffic analysis
This is a proposal to add a messaging protocol that is resistant to traffic analysis. The protocol would allow a message of reasonable length to be sent to a relay, which would then store the message for a variable period of time before forwarding to the next relay in the circuit. Circuits would be built using the message store-and-forward protocol to send setup messages, including circuits to and from Tor hidden service rendezvous points. The variable delay time could potentially be programmed by the client in the message wrapper.
Clients could take advantage of this protocol (including Tor hidden services) to implement messaging clients that are resistant to traffic analysis, i.e., the variable delay between the time messages are received and sent would make it vastly more difficult to determine the endpoints of a message by observing the packets being sent between a set of relays. This protocol would not be suitable for "realtime" applications such as web browsing and voice or video communication; it would only be suitable for text messages, file transfer and similar non-realtime applications.