Privacy

31876 readers

365 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

Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post
Don't promote proprietary software
Try to keep things on topic
If you have a question, please try searching for previous discussions, maybe it has already been answered
Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience
Be nice :)

Related communities

Chat rooms

[Matrix/Element]Dead
Discord

much thanks to @gary_host_laptop for the logo design :)

founded 5 years ago

MODERATORS

[email protected]

Privacy concerns with DHCP (DHCP fingerprinting) (lemmy.zip)

submitted 4 months ago* (last edited 4 months ago) by [email protected] to c/[email protected]

44 comments fedilink hide all child comments

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

[–] [email protected] 2 points 4 months ago (2 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.

[–] [email protected] 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.

[–] [email protected] 2 points 4 months ago

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

[–] [email protected] 1 points 4 months ago

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

[–] [email protected] 1 points 4 months ago (2 children)

Most modern operating systems randomize the MAC.

that doesn't seem to be uniform behaviour. but i think we agree on the merit. if you are this paranoid, you just don't use networks where you don't have control over the local segment.

[admin@MikroTik] > ip arp print 
Flags: X - disabled, I - invalid, H - DHCP, D - dynamic, P - published, C - complete 
 #    ADDRESS         MAC-ADDRESS       INTERFACE                                                    
 0 DC 192.168.88.160  A2:35:xx:xx:xx:xx bridge                                                       
 1 DC 192.168.88.159  F4:60:xx:xx:xx:xx bridge                                                       
 2 DC 192.168.0.1     44:32:xx:xx:xx:xx ether1                                                       
 3 DC 192.168.88.168  18:3D:xx:xx:xx:xx bridge                                                       
 4 DC 192.168.88.156  70:BB:xx:xx:xx:xx bridge

[–] [email protected] 1 points 4 months ago (1 children)

you just don't use networks where you don't have control over the local segment.

Easier said than done. Sometimes it's not an option.

[–] [email protected] 1 points 4 months ago

there is always an option. unless you are pressured by lets say some state authority or your employee, in which case your identity is probably well known and they don't really need to spy on you through dhcp.