Any way to transfer a Signal profile to a new phone without SIM?

uid0gid0

I have a Signal profile which I would like to keep, but I can't "register" a new device since I
don't have access to the old SIM number I used to register on Signal.

The official way of achieving that would be a no-go:
https://support.signal.org/hc/en-us/articles/360007059752-Backup-and-Restore-Messages#android_transfer
They still require the new phone to be able to receive the SMS confirmation.

Now, I don't really care about the message history, so projects I came across such as:
https://github.com/bepaald/signalbackup-tools are unlikely to help in this case.

Anyone knows an alternative way of doing it?

uid0gid0

I'll extend the question to WhatsApp as well.
The idea is just to keep the old number which is a priority, not the chat history which is less important.

As far as I understand, some of the keys in such apps are kept in the Android Keystore, thus making
it impossible to extract from the userspace in any legit way?

Another interesting read about "cold attacks" against Signal would be:
https://github.com/AvillaDaniel/Signal-Forensics

However this is not quite the case here, it's always nice to have a demo of the physical
device attack threat model.

kosa

I have seen some app capable of transferring applications with app-specific data between phones, I dont' remeber its name, but it requiered both phones to be rooted to make it work. It is not a legit way, it is dangerous one, Never tested it with whatsapp or signal, but games worked. I'm sorry to disappoint you.

uid0gid0

kosa

Well, both rooted phones is not what we are really after here, just for some app?
I can compile my own GOS, and bundle whatever privileged apps I wish, but no,
rooting both phones for that is an overkill. You don't buy a cow to get a glass of milk.

BluishHumility

If you no longer have access to that SIM and are going to lose control of the number, you should not attempt to keep using that number on your Signal account. The provider can release the number back to the pool and assign it to a new SIM at any time.

If the new customer who gets that number uses Signal, they could at best disable your account at some random time in the future (without intending to or even knowing they are doing it), or at worst they could take control of your Signal account.

uid0gid0

BluishHumility
The provider can't, I setup 2FA on that number, which essentialy means nobody
is going to reuse this number, but this is not the concern either, I just need to transfer
it to a new phone, and the number was registered in a country with an anonymous SIM,
and after 2 years there is no way to reactivate this number without going to that specific
country, where I believe I can "receive" any number for merely a few dollars at any corner shop.
Country: TZ.

Well, I guess I will just have to keep the old phone even way after GOS stops releasing any updates.

pdagenius

https://support.signal.org/hc/en-us/articles/360007062012-Change-Number