Opened 6 years ago

Closed 5 months ago

#13508 closed enhancement (wontfix)

Add messaging protocol that is resistant to traffic analysis

Reported by: Alan Owned by:
Priority: Medium Milestone: Tor: unspecified
Component: Core Tor/Tor Version:
Severity: Normal Keywords: messaging protocol store-and-forward traffic-analysis needs-proposal hard mixnet research-program
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:


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.

Child Tickets

Change History (3)

comment:1 Changed 6 years ago by nickm

Keywords: traffic-analysis needs-proposal hard added; traffic analysis removed
Milestone: Tor: unspecified

It would be interesting to do something like this, not as a built-in part of tor, but a plug-in mechanism where Tor relays can provide a covert channel for clients to send them either padding information or data to introduce into a high-latency mixnet.

comment:2 Changed 3 years ago by nickm

Keywords: mixnet research-program added
Severity: Normal

comment:3 Changed 5 months ago by nickm

Resolution: wontfix
Status: newclosed

This is still a decent idea, but this ticket isn't the right place to do it. First step would be a bunch of scoping and design work and proposal writing. Also have a look at Loopix for a recent deployed mixnet-type system.

Note: See TracTickets for help on using tickets.