.
Tor still does better than anything else. I don't think it's worth scaring people away from using Tor, because whatever else they'd be using instead is certainly worse.
EDIT: Parent comment originally said words to the effect of "Reminder that Tor has no defence against global traffic analysis".
It's possible to guard against global traffic analysis by establishing permanent fixed-bandwidth links between each node and sending traffic along them even when they aren't assigned to a circuit (or the circuit is idle). Then there is nothing to passively analyze because the amount of traffic between each node is always the same.
The problem is that this consumes a very large amount of bandwidth.
If you instead ask yourself "how many Tor nodes are out there"[1], and then ask yourself "what is the NSA's annual budget"[2], the concept of a global active adversary makes me a bit nervous.
[1]: http://torstatus.blutmagie.de [2]: https://www.theverge.com/2013/8/29/4672414/leaked-snowden-do...
And does not run 100%bandwidth all day and all night.
Resisting global traffic analysis for the purposes of deanonymization is not so easy. The issue is that if every time Alice sends ~476MB of traffic, Bob promptly receives ~476MB of traffic, it's not hard to deduce that Alice is talking to Bob. To fix that, the amount and timing of the traffic Bob receives needs to be independent of the traffic Alice is sending him. Which is possible but inherently comes at an efficiency cost.
I can imagine a global passive adversary that could log all Internet traffic, and make it searchable. The NSA can somewhat do that. But even the NSA can't retain everything for more than a few days, if even that. So even retaining necessary data for a match would be a stretch. Let alone having the processing power needed to do the matching.
We're talking about an attacker that can see every byte going over the wire, encrypted or not it's still able to measure the volume of data itself.
> Well, first thing, you don't send many MB directly to someone. You put it on a Tor onion file-share site, and PM the link via Tor.
In that example the attacker wants to determine the location/IP of the hidden service itself. It's pretty well known that high traffic / volume hidden services are some of the easiest targets for global traffic analysis.
> I can imagine a global passive adversary that could log all Internet traffic, and make it searchable. The NSA can somewhat do that.
They don't have to log the data itself simply the meta data and in specific the volume of data sent between vertices in the graph. Various agencies have openly admitted they keep this information and it's not considered "protected" in their view.
This is simply a graph analysis problem, similar to how Bitcoin is pseudo-anonymous unless you use specific methods that aren't built into the core protocol.
And about onion file-sharing sites. With OnionShare, you can create a site just for that transfer.
If Alice uploads the file and Bob downloads it immediately then you haven't gained anything. Bob has to wait some time for it to work, which means you didn't actually need a low-latency anonymity network to begin with. You can't use it for things that actually need real-time communication, like for live streaming or anything interactive.
I agree about unworkability for real-time communication. But there, you want to keep messages small. And use padding. Trying to make live streaming anonymous is nontrivial.
I mean, if only 100 people use I2P, and some traffic has gone over I2P, you can quite easily narrow it down to the set of 100 people.
I'd be delighted to be proved wrong.