Is there any way to hide my using the internet (or maximize privacy) when connected via router to other computers?

Question

I shall begin my question with the remark that I am not tech savvy at all!

The problem is the following:

A cluster of computers (laptops, desktops, etc.) A, B, C, D... are all connected to the same router. Let's say my computer is computer A and I am a guest at big brother Bob's home, who owns the router and computers B, C, D...

Assuming Bob has no physical access to my computer but can access the other computers, is there a way to prevent Bob from knowing what I am doing on the internet, or even better, to completely hide from Bob that I used internet at all? (short of his contacting his ISP and demanding a report or something which would take a non-trivial amount of time and assuming I don't download anything or watch HD videos which could show up as a sudden spike of consumption)

When it comes to hiding the names of websites I visit and internet searches, according to some research it seems like Tor does a good job in hiding it completely, even if the ISP is contacted. However, can Bob determine quickly (i.e. without contacting his ISP, using some cmd dark arts) that computer A has connected to a Tor node at all without physically accessing computer A? (Let's say it's not in the cluster anymore when Bob does his checks)

According to further research it seems to be impossible to get the internet history of all connected devices to a router without access to the devices, but I am unsure and opinions seem to vary somewhat.

TL;DR I'm basically looking for a way to make my internet usage as inconspicuous as possible during a very specific time period when indirectly connected to other computers via a router I don't own, is using Tor the best thing I can do in this situation to maximize privacy?

Thank you.

Answer 1

Let's take this from Tor backward.

Yes using Tor is likely going to maximize your privacy and anonymity. That said, Tor comes with usability issues that may not be worth the pain for your needs. You can try Tor easily enough by downloading and running TBB (Tor Browser Bundle). Anyone who can access the router traffic can see that you are using Tor but no content or destination information.

A commercial VPN service will provide a secure encrypted connection out through the router without the usability issues of Tor. Anyone who can access the router traffic can see that you are using a VPN but no content or destination information. Of course the VPN can see what you're doing, but you didn't indicate that was a problem.

Doing nothing special on a switched network. Normally the router connects everyone via a switch. This means that the other computers would not normally be able to see your traffic anyway unless they can access the router traffic (or router logs). It's technically possible to poison the network, but I'm assuming you're in a benign environment.

Answer 2

Lets turn this question around. What can Bob do to monitor your network traffic? And what can you do to stop it?

Since you are at Bob's house. Bob controls his router configuration. All your network traffic goes through his router. If he has the technical skill and equipment, he can monitor every packet you send.

An easy and common thing for people to do to their router is to configure openDNS as their DNS server. Then they can block certain (usually inappropriate) categories of websites and get reports on what websites were contacted. Many parents do this.

The DNS server configured on the router is "offered" to the clients on the net via DHCP. You can statically set your own DNS server. Some public DNS servers on the Internet have a reputation for respecting privacy. You have to decide which public DNS server to trust and statically configure it. That stops openDNS-style monitoring.

A less common configuration is to have the router directly log traffic through it. It used to be rare for consumer router gear to be able to do this well, but since he owns the router it is possible. But some of the new "Wifi Mesh" systems have built-in security. Eero Secure is an example. According to the website, it blocks inappropriate and illegal content. I don't know if it generates reports regarding what it blocked. I don't personally know how Eero Secure does the blocking or reporting (worthy of a separate question).

The way to prevent Bob from seeing your traffic in this case is to use a VPN service. He will be able to see that you are using the VPN service, but not what you are connecting to beyond it. As user10216038 warned, the VPN service can monitor you.

My recommendation is to not access anything on Bob's network that would make Bob upset. You can always use a personal hotspot on your phone. That bypasses his network completely. Of course then your ISP can monitor you (as always).