this post was submitted on 04 Jul 2024
4 points (59.1% liked)

Privacy

32096 readers
696 users here now

A place to discuss privacy and freedom in the digital world.

Privacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy.

In this community everyone is welcome to post links and discuss topics related to privacy.

Some Rules

Related communities

much thanks to @gary_host_laptop for the logo design :)

founded 5 years ago
MODERATORS
 

So many people here will go though great lengths to protect themselves from fingerprinting and snooping. However, one thing tends to get overlooked is DHCP and other layer 3 holes. When your device requests an IP it sends over a significant amount of data. DHCP fingerprinting is very similar to browser fingerprinting but unlike the browser there does not seem to be a lot of resources to defend against it. You would need to make changes to the underlying OS components to spoof it.

What are everyone's thoughts on this? Did we miss the obvious?

https://www.arubanetworks.com/vrd/AOSDHCPFPAppNote/wwhelp/wwhimpl/common/html/wwhelp.htm#href=Chap2.html&single=true

you are viewing a single comment's thread
view the rest of the comments
[–] Max_P@lemmy.max-p.me 5 points 4 months ago (14 children)

I guess the hostname could be used to defeat MAC randomization if you use public WiFi like hotels, airports and coffee shops. You could probably identify repeat users if you cared enough.

But then your worry should be the security cameras not the WiFi, because that's what's gonna tie you personally to your device connecting.

[–] 14th_cylon@lemm.ee 3 points 4 months ago* (last edited 4 months ago) (10 children)

Your router always knows your Mac address, no matter how you got your ip assigned. And yes, you can use it to identify the client - that is why it is there. This whole post is nonsense written by someone who doesn't really understand what dhcp is or how it works. Long story short, don't look for privacy on local Ethernet segment :D

[–] Max_P@lemmy.max-p.me 2 points 4 months ago (7 children)

Most modern operating systems randomize the MAC. DHCP does have extra fields such as the device's hostname that can be used to counter that.

But as I said, that's unlikely to be the weakest link. If you don't trust the network you're also likely in a public environment where people can just see you anyway.

[–] user134450 4 points 4 months ago (2 children)

Most modern operating systems randomize the MAC.

[citation needed]
having the option to randomize the MAC is not the same as actually doing that. There are also a few downsides to random MACs, like captive portals not remembering you on public WiFis.

[–] Redjard@lemmy.dbzer0.com 2 points 4 months ago

The default on android is to give every wifi network its own random but static mac.

[–] delirious_owl@discuss.online 1 points 4 months ago

Captive portals not remembering you between sessions is a huge bonus for captive portals with time limits.

load more comments (4 replies)
load more comments (6 replies)
load more comments (9 replies)