Can I batch multiple transactions while _not_ connected to the internet?

[davidbak]

(I'm new to Electrum.)

I'm going to use Electrum (in Tails OS), configured to talk only to the Electrs on my own Raspiblitz, to transfer coin from a bunch of paper wallets to a proper deterministic wallet.

The paper wallets of course are all P2PKH, and I expect to have to type in private keys (tedious but I've done it before).

• Unless there's a way in Electrum to scan a WIF private key?

I can make an Electrum wallet to match my hardware wallet seed+passphrase.

• Unless I can't actually use a seed+passphrase with Electrum, only a seed?
  

Anyway, I'd like to have Bitcoin Core on the Raspiblitz fully sync'd, then turn off my cable modem (isolating my LAN from the network), then, in that configuration prepare and sign a bunch of transactions - one for each paper wallet.  And then either

• Delete the private keys from Electrum (how?), reconnect to the internet, and broadcast all transactions at once, or
• Export the signed transactions to some file (on a USB key), reboot (the private keys are definitely gone now), reconnect to the internet, import the transactions, and broadcast them, or
• ???

What I'd really like to avoid is doing the disconnect/enter private key/sign transaction/reboot/connect/transmit for each paper wallet.

Hopefully you'll tell me the first option above just works: all the signed transactions just stack up with no place to go until the internet is available and then off they go.  If not though, then what?

[1715653014]

1715653014

[pooya87]

This is not the correct way of setting up a cold storage or claiming coins offline. What you need is 2 devices or at least 2 operating systems, one completely and always offline and the other online.

On the offline system you install Electrum and create a new wallet (you can't import new keys in an existing wallet that has a seed).
Import the private keys there to get the corresponding addresses.
Create a new wallet with seed (in Electrum or using your hardware wallet) and get a new address to receive the coins in the end. Lets call this ADDR.

On the online system install Electrum and let it sync. Now create a new wallet but this time import the addresses and let the wallet sync to get your transaction history.
Go to the Send tab and enter ADDR in Pay to field and click the Max button in front of Amount. By doing this you are "batching" all your coins in that watch-only wallet and sending it all to ADDR. Set the fee and create the transaction (unsigned). Copy it and move it to your offline system.

On the offline system import the transaction you just created and double check that everything is correct (destination address and amount). Sign this transaction and again export it.

Back to online system you import the now signed transaction and broadcast it.

[davidbak]

OK, I can do it that way, thank you because it is exactly what I needed to know.

A couple of followups:

• This procedure you described is not using the "sweep" feature, correct?  So I'm entering the destination address (from hardware wallet) manually?  (Or via QR code?)
• Can I use seedphrase + passphrase w/ Electrum, or only seedphrase?

TIA

[pooya87]

• This procedure you described is not using the "sweep" feature, correct?  So I'm entering the destination address (from hardware wallet) manually?  (Or via QR code?)
• Can I use seedphrase + passphrase w/ Electrum, or only seedphrase?

- Yes because last time I checked (which is a long time ago) "sweep" didn't let you use multiple keys and had to do it one at a time. Also if you create a new watch-only wallet file using the addresses you can always keep that wallet and check your balance in the future easily.
- Yes, Electrum lets you add extra words to your seed phrase known as passphrase. When importing the seed phrase there is an "Options" button that you can click to select this option.

[nc50lc]

I can make an Electrum wallet to match my hardware wallet seed+passphrase.

• Unless I can't actually use a seed+passphrase with Electrum, only a seed?
  

A couple of followups:

• -snip-
• Can I use seedphrase + passphrase w/ Electrum, or only seedphrase?

In case you missed it, Electrum has an option to create a wallet using your hardware wallet without entering its seed+passphrase.
The option is in new wallet option "Standard wallet->Use a hardware device".

[o_e_l_e_o]

Just a couple of other points:

Unless there's a way in Electrum to scan a WIF private key?

If your paper wallet as a QR code on it, then on the import private keys screen there is a camera icon at the bottom right of the text box you can click. If your paper wallet only has the private key in WIF format, then you will need to enter it by hand.

I can make an Electrum wallet to match my hardware wallet seed+passphrase.

The only way you should use Electrum to interact with your hardware wallet is as nc50lc has described in the above post. If you take your seed phrase +/- passphrase from your hardware wallet and set up a new Electrum wallet with it by typing them in, then you have completely negated all the security your hardware wallet gives you by exposing your seed phrase and passphrase to the internet. You should only use Electrum as an interface to interact with your connected hardware wallet, and not to duplicate the hardware wallet to an Electrum wallet.