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Use Tails or Whonix which prevents leaking data outside of the Tor network. Qubes OS makes Whonix easy/transparent (though I haven't had the pleasure of trying

Use Tails or Whonix which prevents leaking data outside of the Tor network. Qubes OS makes Whonix easy/transparent (though I haven't had the pleasure of trying out Qubes yet). Never access files downloaded over Tor outside of those environments, and _never_ mix identities: if you're going to be pseudononymous, don't access files downloaded under another pseudonym or visit websites you'd access (especially if logging in) under another. If you're going to be anonymous, don't save the data: let it be ephemeral, which is easy in the case of Tails, which is ephemeral by default. Always use Tor Browser, not Tor over Foxyproxy in a vanilla Firefox or something. Don't rely on torify on your normal setup for complete anonymity, for reasons above. But it depends on your threat model. I _do_ do both things in the previous paragraph for my day-to-day stuff where my threat model involves e.g. advertisers and other privacy-invading trackers, where I'm reading tech-related articles or downloading videos of talks, for example. But that involves a number of other addons as well (e.g. Privacy Badger, HTTPS Everywhere, NoScript, uBlock Origin, self-destructing coookies, ...). Edit: Forgot to mention: https://www.whonix.org/wiki/DoNot https://www.whonix.org/wiki/DoNot

dukeluke 10y ago
It's also a good idea to assume Tor is already pwned and to follow good opsec(burner devices, mac address cloaking, using open/pwned wifi APs, loading & running OS completely through ram, and use hard drive write blockers). True anonymity is tough nowadays.
- mikegerwitz 10y ago
  Tails randomizes the MAC address by default, I believe. (Edit: https://tails.boum.org/contribute/design/MAC_address/ https://tails.boum.org/contribute/design/MAC_address/) But yes, you need hardware you can trust. Burner won't be a bad idea if your life depends on your anonymity.
  - chopin 10y ago
    Out of curiosity: Why is this necessary? Being not exactly a network expert I would have assumed that leakage of the MAC address terminates at the next router or switch (which eg. would be my home router, if using TOR from home). Is the MAC address part of IP packets somehow?
    - FungalRaincloud 10y ago
      Typically, the MAC address is not public beyond the next router. Software could intentionally leak it, but I don't think that's likely on a system built for anonymity. However, it is possible that, should your traffic get traced to your true IP address, interested parties would attempt to then trace it to an individual. Any router you connect to could be storing access logs (or even passing them on to the next connection point) for a long enough time that they could narrow down which MAC the traffic came from. If they have you on camera, and the recorded MAC matches your PC, that's a bit more evidence. Sure, you could potentially fight it in court (MACs can be trivially spoofed, after all!), but why bother taking the risk?
    - moyix 10y ago
      It's not part of the IP packet, but in some previous cases exploits on Tor (such as the one the FBI used in the Freedom Hosting takedown) have explicitly queried the MAC address and then exfiltrated that information. I assume the intent was that they could then arrest the suspect and compare the captured MAC address to the physical machine to prove it was the same person.
      - angry_octet 10y ago
        In addition to providing confirmatory evidence, MACs are essentially serial numbers in a can. Every batch of chips sold can be traced to an OEM. If that was a laptop OEM then the manufacturer will know the serial number of the device with that MAC, and CPU ID etc. There is a good chance they can trace who initially purchased the laptop. Also, if it is a WiFi MAC then your laptop is blasting that out constantly, and many services collect that info. Fortunately we are slowly seeing a move to randomisation of the MAC used when scanning. Unfortunately an active probe can pierce the veil by causing the true MAC to be used. Lots of venues (shopping malls) offer free Wifi because it causes the phone to reveal its true address when it connects, allowing tracking (lots of other entropy in Wifi apart from the MAC though). There is no reason random MACs shouldn't be used for all transmissions in modern systems except for software inertia.
ryanlol 10y ago
>Use Tails or Whonix which prevents leaking data outside of the Tor network. Qubes OS makes Whonix easy/transparent (though I haven't had the pleasure of trying out Qubes yet). Use Whonix, not Tails. Tails doesn't do a particularly good job preventing leaks outside of Tor network.

dukeluke 10y ago

It's also a good idea to assume Tor is already pwned and to follow good opsec(burner devices, mac address cloaking, using open/pwned wifi APs, loading & running OS completely through ram, and use hard drive write blockers). True anonymity is tough nowadays.

mikegerwitz 10y ago
Tails randomizes the MAC address by default, I believe. (Edit: https://tails.boum.org/contribute/design/MAC_address/ https://tails.boum.org/contribute/design/MAC_address/) But yes, you need hardware you can trust. Burner won't be a bad idea if your life depends on your anonymity.
- chopin 10y ago
  Out of curiosity: Why is this necessary? Being not exactly a network expert I would have assumed that leakage of the MAC address terminates at the next router or switch (which eg. would be my home router, if using TOR from home). Is the MAC address part of IP packets somehow?
  - FungalRaincloud 10y ago
    Typically, the MAC address is not public beyond the next router. Software could intentionally leak it, but I don't think that's likely on a system built for anonymity. However, it is possible that, should your traffic get traced to your true IP address, interested parties would attempt to then trace it to an individual. Any router you connect to could be storing access logs (or even passing them on to the next connection point) for a long enough time that they could narrow down which MAC the traffic came from. If they have you on camera, and the recorded MAC matches your PC, that's a bit more evidence. Sure, you could potentially fight it in court (MACs can be trivially spoofed, after all!), but why bother taking the risk?
  - moyix 10y ago
    It's not part of the IP packet, but in some previous cases exploits on Tor (such as the one the FBI used in the Freedom Hosting takedown) have explicitly queried the MAC address and then exfiltrated that information. I assume the intent was that they could then arrest the suspect and compare the captured MAC address to the physical machine to prove it was the same person.
    - angry_octet 10y ago
      In addition to providing confirmatory evidence, MACs are essentially serial numbers in a can. Every batch of chips sold can be traced to an OEM. If that was a laptop OEM then the manufacturer will know the serial number of the device with that MAC, and CPU ID etc. There is a good chance they can trace who initially purchased the laptop. Also, if it is a WiFi MAC then your laptop is blasting that out constantly, and many services collect that info. Fortunately we are slowly seeing a move to randomisation of the MAC used when scanning. Unfortunately an active probe can pierce the veil by causing the true MAC to be used. Lots of venues (shopping malls) offer free Wifi because it causes the phone to reveal its true address when it connects, allowing tracking (lots of other entropy in Wifi apart from the MAC though). There is no reason random MACs shouldn't be used for all transmissions in modern systems except for software inertia.

ryanlol 10y ago

>Use Tails or Whonix which prevents leaking data outside of the Tor network. Qubes OS makes Whonix easy/transparent (though I haven't had the pleasure of trying out Qubes yet). Use Whonix, not Tails. Tails doesn't do a particularly good job preventing leaks outside of Tor network.