Installing GOS from a public library

miketrey

My goal is an anonymous phone.
pixel 7 pro. bought used. factory reset.
intended to go my local library and install GOS
library has windows 11, which needs fastboot driver to install
can't install without systems admin
can't circumvent by installing another OS on public library computer because I still need sytems admin
so i get kind of impatient, I should have asked here first
take my laptop to public library and successfully install GOS flawlessly

my question is, did I leave any trace of my location, identity, etc on the phone by using my personal laptop or the libraries wifi?

I know I should have asked here first.

I'm a bit of a noob. thanks in advance!

Agility8200

miketrey I'm not super knowledgeable on the amount of state the phone stores outside of user profiles and that persists across wipes/resets. But my understanding is the installer only flashes signed images and the device specific GrapheneOS AVB Key Pixel 7 Pro: bc1c0dd95664604382bb888412026422742eb333071ea0b2d19036217d49182f onto the device that are then later verified on every boot/load. So my answer is that there probably aren't any traces of the machine that installed GrapheneOS on your P7Pro, but that doesn't mean the computer you used can't collect any data about devices it has seen through fastboot and report it through telemetry later. I have no evidence this is currently happening but it's at least feasible.

I would recommend following the post-install steps of re-locking the bootloader, disabling developer mode, and using Auditor to attest you have an unmodified GrapheneOS install.

But let's talk about your threat model for a moment. You say you want an anonymous phone, but anonymous how the device still has a globally unique IMEI that it broadcasts to cell networks and if paired with a SIM card it will have an IMSI it will also use to authenticate to cell networks. Cellular data/telephony services inherently need to know where the device is in order to route messages/calls/data to/from the device. This will build up a history of your location movements that can identify who you are based on where you live/work and is accessible to your Telecom, any malicious employees, anyone who hacks them, or any LE (even fake) that asks for that data.

So what is your threat model? What are you trying to protect, from which adversaries, what are their capabilities, and what negative outcomes follow from your adversaries breaching your protection?

P.S.
This was the GrapheneOS accounts response to a similar question.

GrapheneOS The device's serial number will be recorded in USB logs each device it's attached. Perform the install from another Android device and factory reset afterwards if you want a strong guarantee. It's a very niche property you want to achieve. Simply attaching it to charge would be no different.

Oggyo

miketrey take my laptop to public library and successfully install GOS flawlessly

So, what are you achieving by using a public computer (library) to install GrapheneOS on your phone?
And how different is using your laptop in a public library (or public WiFi) than connecting it via VPN when at home for example?

[deleted]

I believe an anounymous phone is impossible by its definition. It is somewhat possible to make a minimal trace by using public WiFi and hiding your routes, but keeping the device completely anounymous is basically impossible. The IMEI, fingerprints and DNA on your device, radio connections, etc., unless you enable the airplane mode all the time, only handle the device with gloves, hide from cameras and people beyond you, and trash the phone after a few days or a week at maximum, an evidence that you were the owner of that phone will always come up when someone tries to figure it out. So my recommendation is that, think of your threat model again. Why someone would need an anonymous hardware anyways?

MoonshineMidnight

Some people like the concept of an anonymous phone, but don't have an actual threat model that meets the need and I could see what is needed being tedious. Pay cash for the phone, flash GOS using a VPN on your personal laptop, and never put a SIM in the phone. Not even a cash paid burner SIM. Have the phone otherwise turned off at home. Turn phone on at various WiFi hotspots and use apps like Session for e2e to other Session users and XMPP/Cheo to call anyone with always on VPN like Mullvad - which you would have to pay with Monero. MAC randomization will help prevent being location tracked by WiFi APs. Phone always in airplane mode, location off, Bluetooth off and WiFi and Bluetooth scanning off. As for why you need to do this, that's on you. Understand anyone you communicate with can dox you about those communications unless they truly do not know who you are, but then who do you call/text outside of a doing whistleblow to a reporter?

riddlemethis

Probably unnecessary overkill. And potentially exposing yourself to unnecessary risk from god knows what's running on those public computers.

If you currently have a GOS phone or tablet, you can install using Vanadium. Works great. Remember to enable USB debugging or it wont work come the fastbootd step.
Use a trusted private dns setting (e.g. base.dns.mullvad.net) in your network settings. And use public wifi or VPN over your home internet.

Or simply a home computer with the above also.

That's probably your best option.