Can regenerate "change received" address after recover with paper backup?

[dr__watson]

Hi (and thanks in advance for your time and any help you may provide),

So, my problem is I've sent some bitcoin using Armory but I cannot get back the change. I can see the transaction (in www.blockchain.com), with two destination addresses: first address is the one I intended to send bitcoin to, and the second one I understand is the "change destination" address generated by Armory (where the change amount is sent). Unfortunately my drive went nuts after that, goodbye .armory and .bitcoin folders. Now I'm trying to recover my wallet using the paper backup.

Paper backup seems to work ok, but I don't see my "change destination" address anywhere. Armory is still offline while the blockchain loads, but meanwhile I've tried to ask Armory to generate new addresses using 'receive bitcoin' option. Then I export the key list (as described here). But none of those addresses is the change address I'm looking for. My guess is that maybe the "change destination" addresses are generated separately (?). Is there any way to ask Armory to tell me the "change destination" addresses?

Thanks again for your help, is greatly appreciated

[goatpig]

Do you know the change address? Does it start with a 3? At any rate, once Armory is online it will find the change the address.

[dr__watson]

Yes It starts with a 3.

I could put armory back on it's feet again, and truly there it is the transaction. I have been able to recover all my funds, thanks!

Still, I wonder how to regenerate the change address if this happened again... It might be useful to other users todo 

[goatpig]

Still, I wonder how to regenerate the change address if this happened again... It might be useful to other users todo 

An address expresses a public key with some added meta data. There can be several addresses for a given public key. In the case of Armory, there are three. When you get Armory online, or when you take a transaction to an offline signer, Armory will detect which public key was used. That is because it carries all address variations per public key.

This change came later in Armory's life. At first Armory only had one address type, before P2SH was a thing even. Therefor, Armory's GUI was not built with that kind of future in mind. When I added the new address types (that was the segwit support release), I opted to let the GUI display a single address per public key and detect which address type was being used in the background.

As a user, when you generate an address, it is assigned the default type as displayed in your settings. In Expert User mode, you can modify this address type on the fly in the new address creation dialog. In your specific case, you'd have to generate new addresses while you cycle through the 3 different types until you find what you're looking for.