Quick Summary of recent traffic correlation using netflows
Here’s what you need to know about the recent research study on traffic correlation attacks:
While it’s great to see more research on traffic correlation attacks, this is not a new area of research. This is one study on the subject in a controlled environment using one readily available traffic monitoring technology to analyze Tor traffic. The researcher has clarified in the media that it was only 81.4 percent of their experiments not “81 percent of all Tor traffic” as has been reported elsewhere.
The Tor network provides anonymity by routing the user’s information through multiple servers (usually three) so that it is hard to detect the person’s physical location.
Tor protects users by:
1) encryption to ensure privacy of data within the Tor network,
2) authentication so clients know they're talking to the relays they meant to talk to, and
3) signatures to make sure all clients know the same set of relays.
In theory it may be possible to track Tor users by linking up their entry and exit points on the network but it is generally very difficult to do so. The Tor network design, however, does not protect against a targeted attack by a global passive adversary (such as the NSA) intent on figuring out whom to investigate through watching and measuring Tor traffic going into and out of the network and correlating the information on both sides. We encourage you to learn more about what Tor does provide.
Tor is used by 2.5 million people a day including the general public, journalists, companies, activists, military, and law enforcement and is a very safe, reliable way to protect your privacy on the Internet.
Don't forget ISPs, especially those (nearly all?) that sell your data to the highest bidder (often after charging grandiose prices for lousy service).
Unfortunately, the threat of tampering by exit nodes, coupled with the paucity of sites that employ properly implemented, full HTTPS encryption and authentication, and the reality that many sites block access to Tor IPs, all contribute in creating a situation in which the usefulness of Tor is extremely limited.
I would very much know what needs to be changed to make Tor provide bullet-proof security against attackers like the NSA. I do not believe the NSA is more powerful or resourceful than the Chinese government for example. I am sure great minds are working together to help get Tor provide even more privacy and more security. The world needs it.