TOR¶
The Tor browser is known to be one of the most secure and private browsers in existence. The Tor browser is often used by those living in oppressive countries that attempt to hide or censor important information from their citizens.
When it comes to the “proper” way to use Tor, it can get quite confusing. Many different people have many different opinions on whats best, so it is important that everyone does their own research and base their opinions off of what they think is best.
Below are some opinions regarding the use of VPNS which is a highly debated topic.
Regarding VPN usage:¶
According to the official Tor guide and website, you can “very well decrease your anonymity” by using a VPN in addition to Tor. While in theory a VPN should provide an extra layer of security, there are a few things that privacy-conscious users should keep in mind. One of the biggest mistakes a Tor user can make is choosing the wrong VPN provider. It is known that most VPN providers keep logs of both internet traffic and your payments, so it is extremely important that each user does their own research to determine which (if any) VPNs fit their threat model. If you would like a brief summary of the top privacy VPNs, you can read this section.
Another aspect Tor users need to remember when using a VPN is that a VPN acts as a permanent entry or as a permanent exit node. This means that your VPN endpoint can (in theory) become a single point of failure. At the end of the day, the use of a VPN can both greatly increase or greatly decrease a user’s privacy; these risks should be heavily considered and researched before committing to any one way.
One big use case for VPNs with Tor is circumventing censorship. If an oppressive government blocks known Tor nodes (which is very common), a VPN can mask the true destination of a user’s requests.
Whether or not to use a VPN depends on the user, their risk tolerance, and their adversary. As the Tor Foundation put it:
“Who’s your adversary? Against a global adversary with unlimited resources more hops make passive attacks (slightly) harder but active attacks easier as you are providing more attack surface and send out more data that can be used. Against colluding Tor nodes you are safer, against blackhat hackers who target Tor client code you are safer”.(??, ????)
Bridges¶
Please navigate to Link [2] for more information.
Timing attacks¶
A “Timing attack” is a method of deanonymization which works by observing the timing of data entering and leaving the network. Alone, these times are almost irrelevant however if an attacker controls both the entry and exit nodes (and the user is on unpatched / old software) an attacker can compare the times from these nodes and deanonymize the user. This type of attack has been seen in the wild and according to a Bleeping Computer article: “The documents related to the information provided strongly suggest that law enforcement agencies have repeated and successfully carried out timing analysis attacks against selected gate users for several years to deanonymize them,” stated CCC’s Matthias Marx.” (??, a)
While this attack has been used in the wild, the tor foundation has stated that they have done “extensive work to flag and remove bad relays has taken place in the past years” as well as “the version used by the deanonymized user was retired in June 2022 and has been replaced by the next-gen Ricochet-Refresh, which features Vanguards-lite protections against timing and guard discovery attacks.” (??, a)
“Maybe, but timing attacks are something that happens when you are being targeted, specifically. There’s a lot of misinformation about exit nodes. A snooping exit node cannot identify you. Tor uses perfect forward secrecy to prevent the exit node from seeing what the entry and intermediate nodes see. In other words, it makes it impossible for the exit node operator to find out where the data request originated from, especially if you’re connecting to an HTTPS site because then they can’t even see what you’re doing. Using a VPN over Tor is going to prevent your circuit from changing. All of your nodes in the circuit are fixed. The only use this has is if, for some reason, a site is blocking all of Tor’s exit nodes; you can use a VPN at the end. Other than this, it has no real purpose. If you’re wanting more anonymity, use Tor over VPN. This prevents your real IP from ever connecting to the Tor network. It will also keep your ISP from seeing you use Tor. Also, using this method keeps the VPN separate from the Tor network. The VPN can’t see your Tor activity, and Tor can’t see the VPN, with the exception of the guard. This would make exploiting your VPN much harder because an adversary would have to compromise Tor first. The other method means your VPN is basically acting as a second exit node. All this to say, if you’re just a general web browser, you can probably do whatever you want without being exploited. But if we assume someone is wanting to use a VPN to make themselves more anonymous to the outside world, then you would definitely want to connect to Tor through the VPN, not connect to the VPN through Tor. By the way, here’s the link: Link”. (??, a)