Randomizing my MAC address

Hi, I am using Qubes with mainly Whonix VMs and when using Whonix, the Tor browser to maximize my privacy.

for this purpose, I wondered about randomizing my MAC address.

the scenario that might endanger my privacy is that my WiFi router is taken and based on online times of specific accounts and the matching logs of my Tor use, it could be found out what exactly I am doing, or link different online identities of mine to each other.
if I understand it right, it is probably a good idea to randomize my MAC address because it would always be the same, every time one of my online identities was active.

Am I right here?
Alternatively, it could be an option to encrypt my router logs if that’s easier.

What do you mean your “WiFi router is taken”? Do you mean physically taken or compromised via WiFi?

Randomizing your MAC address is useful when you access WiFi networks that are used by other people. It ensures that the MAC address for a given session doesn’t match any of your hardware or other sessions. It allows you to use the same WiFi again without the two sessions being associated. However, precautions should be taken so that you are not physically associated with the session (your face or car parked near the WiFi network at the time of the session).

As far as using Tor, you might consider:

  1. If you absolutely must maintain privacy/anonymity, don’t use Tor from your own residence. There are ways your location can be exposed - even with Tor.

  2. If you are using Tor at home and want to maximize privacy and anonymity, don’t broadcast a radio signal of your connection. Use a hard wired ethernet connection.

  3. If you are connecting from home and using WiFi, you are probably more secure using a stable MAC address (doesn’t have to be the actual hardware MAC address) rather than a randomized MAC address for each session. That will allow you to configure the router to only allow your specific MAC address to connect (to mitigate local adversaries from gaining access to your WiFi network)

  4. If your personal router is compromised or physically accessed and there are logs of your connections, it won’t matter if the MAC addresses are different. They will all be associated with you.

Aside from using properly configured Qubes OS and/or Tails to make your Tor connections, one of the recommended approaches to maximize privacy and anonymity is to use a WiFi network that is not associated with you or places that you frequent. And given the prevalence of facial recognition, license plate readers and other mass surveillance technologies, it’s ideal to access a given network from a distance using a yagi antennae and keeping your sessions as short as possible because even at a distance, it’s possible for an adversary to triangulate your location relatively quickly.

Finally, for maximum privacy/anonymity, the machine that you use from public WiFi would be dedicated for such use (a “burner” laptop). That means not using the same machine at your own residence or other places that are associated with you - and not accessing any personal accounts from that machine regardless of where your are connected.

Obviously those are extreme measures. I don’t know anything about your threat model. In most cases, you will be fine adopting as many measures as are practical. I’m just pointing out that no network or machine should be considered secure - regardless of how it is configured. And even if they were secure, you can still blow your cover with poor behavior. Your online habits, physical movements and other choices can be an even bigger threat than your choice of computer or operating system.

1 Like

Thank you really much for the good answer!

don’t broadcast a radio signal of your connection. Use a hard wired ethernet connection.

what do you mean by that?

(doesn’t have to be the actual hardware MAC address)

would you recommend to change it once and then leaving it like that, in comparison to leaving the default one?
and does it even have disadvantages of getting a new MAC address for each boot?

They will all be associated with you.

well, I could say someone else entered my WiFi without my knowledge, couldn’t I?

The rest is clear. :slight_smile:

WiFi = radio

I can’t think of any disadvantages of randomizing your MAC at home.

It’s probably better in the long run to spoof your stable MAC address at home, especially if you use WiFi. That way, if your WiFi was ever compromised, your hardware MAC would still remain private). It would also keep your hardware MAC private from your ISP (assuming they are able to see the MAC address of connected devices).

If your car is seen speeding away from the scene of a crime, good luck arguing that someone else must have taken it for a ride. :slight_smile: But yeah, you could argue that someone must have entered your network without your knowledge. Although, you would probably want to randomize your host name as well. Of course, a log of dozens of connections by devices with different MAC addresses and random host names that take the form “pc-#####” would likely appear to be the same user. In the end, it’s best not to do anything from your home network that would require such a defense.

thank you! I have also learned about randomizing my host name. the only problem I have with it is the following:
I am having separate identities in different qubes. I think it could compromise this separate identity privacy in the worst case, because all of them have the same host name, is that right?
Probably only if my system is compromised.

Identities for what? Web logins and services? Web sites don’t see your MAC or hostname. Unless those identities are intended for a local network, it’s a non-issue. If you do need specific MAC or hostname, you can still configure a random default and manually change it whenever you want.

In sys-net terminal:

sudo hostnamectl set-hostname <custom-hostname>

Identities for what? Web logins and services?

yes.

Web sites don’t see your MAC or hostname.

yes. it’s about someone having access to my router logs, or my ISP monitoring me, or me being compromised.