Electrum use in AIRGAPPED Computer | Bitcointalksearch.org

Rath_

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Quote from: krogothmanhattan on February 04, 2019, 04:29:28 PM

https://www.reddit.com/r/Bitcoin/comments/6kek57/question_trezor_on_offline_computer/
Anybody ever try this? If so please let me know.

Yes, but what's the point of such setup anyway? Your private keys never leave TREZOR (unless there is a major security issue but those are fixed relatively fast and usually require a physical access to the device). By the way, since Trezor T supports SD cards and has a built-in screen, in the future it should support offline signing (no need to use any extra software). Unfortunately, no ETA was provided by the developers on their Telegram channel. I am quite sure I have seen a github commit related to this.

krogothmanhattan

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The Stone the masons rejected was the cornerstone.

Ok...came across this thru a forum user.

https://www.reddit.com/r/Bitcoin/comments/6kek57/question_trezor_on_offline_computer/

Anybody ever try this? If so please let me know.

I will attempt this someday when I can find time away from family and work,

krogothmanhattan

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The Stone the masons rejected was the cornerstone.

Downloaded and ran Electrum online and was able to get a forged and signed transaction (hexadecimal string) along with Trezor!

The whole objective of this exercise is to be able to carry any amount of BTC on my phone without it actually being there. Gives me peace of mind....

In the event my phone was hacked or stolen, and the person was able to use the forged and signed transaction (hexadecimal string)...the BTC would goto to a wallet I controlled.

Or if I was to meet someone in person to pay in BTC, I can forge in advance the signed transaction with the agreed BTC address payment.

Once we meet I just broadcast it and done deal Cheesy

So mission accomplished! Thankyou all for your input!

krogothmanhattan

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The Stone the masons rejected was the cornerstone.

Quote from: TryNinja on January 08, 2019, 09:43:00 AM

Quote from: krogothmanhattan on January 08, 2019, 09:30:39 AM

Use a wallet to tie into my trezor BTC and get a signed transaction (hexadecimal string) for sending BTC to an addy of my choice. ALL OFFLINE

You are missing a step there. It has everything to do with past transactions. How can you create the transaction if your wallet doesn't have an internet connection to get your inputs necessary for the raw transaction? You need to build the transaction from a connected device OR have the inputs info already set previously in the wallet software. Otherwise, it's like telling your Electrum wallet to guess the blockchain and which amount of coins you own.

Quote from: krogothmanhattan on January 08, 2019, 09:30:39 AM

Then carry that HEX STRING with me in an email and when ready to SPEND or BROADCAST it I can, without carrying the BTC on my cell phone hot wallet, example Mycellium.

You can (and should) do that online. Just use the "Preview" button. There is no need to use a Trezor hardware wallet offline.

Thanks for the reply...So I cannot do this offline with Trezor and Electrum, it has to be on a computer that is connected to the net? Ok thanks!

Ok I think you have answered all that I wanted to know. For some reason I was under the impression this can be done offline without ever connecting. Cheers!

TryNinja

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Quote from: krogothmanhattan on January 08, 2019, 09:30:39 AM

Use a wallet to tie into my trezor BTC and get a signed transaction (hexadecimal string) for sending BTC to an addy of my choice. ALL OFFLINE

You are missing a step there. It has everything to do with past transactions. How can you create the transaction if your wallet doesn't have an internet connection to get your inputs necessary for the raw transaction? You need to build the transaction from a connected device OR have the inputs info already set previously in the wallet software. Otherwise, it's like telling your Electrum wallet to guess the blockchain and which amount of coins you own.

Quote from: krogothmanhattan on January 08, 2019, 09:30:39 AM

Then carry that HEX STRING with me in an email and when ready to SPEND or BROADCAST it I can, without carrying the BTC on my cell phone hot wallet, example Mycellium.

You can (and should) do that online. Just use the "Preview" button. There is no need to use a Trezor hardware wallet offline.

krogothmanhattan

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The Stone the masons rejected was the cornerstone.

Quote from: Abdussamad on January 08, 2019, 08:58:59 AM

No it isn't. The air gapped PC has no idea about your past transactions so it can't create a spending tx. What you should do is go online since you are using a trezor and it is designed for online use. Otherwise you could try creating a watch only wallet with your mpk (wallet menu > information) on an online system and doing the whole cold storage sneaker net dance. But it makes no sense to own a trezor and then keep it offline as well. Why spend on a trezor if you don't want the convenience and security of being able to use it on an online system?

Thanks for the response. And no..this has nothing to do with past transactions at all.

   What I want to do is.

   Use a wallet to tie into my trezor BTC and get a signed transaction (hexadecimal string) for sending BTC to an addy of my choice. ALL OFFLINE

   Then carry that HEX STRING with me in an email and when ready to SPEND or BROADCAST it I can, without carrying the BTC on my cell phone hot wallet, example Mycellium.

   So if I ever lose my phone or if it is ever hacked the worse case scenario is that Hex string is exposed and if it is used will only send the BTC to the addy it was intended to.

   It makes losing BTC virtually impossible.

Abdussamad

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No it isn't. The air gapped PC has no idea about your past transactions so it can't create a spending tx. What you should do is go online since you are using a trezor and it is designed for online use. Otherwise you could try creating a watch only wallet with your mpk (wallet menu > information) on an online system and doing the whole cold storage sneaker net dance. But it makes no sense to own a trezor and then keep it offline as well. Why spend on a trezor if you don't want the convenience and security of being able to use it on an online system?

krogothmanhattan

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The Stone the masons rejected was the cornerstone.

I am trying to use Electrum in my air gapped computer to forge a transaction, and get a signed
transaction (hexadecimal string) along with Trezor. But I am getting this popup hodling me back.

I then want to take the wallets output and live broadcast it here https://live.blockcypher.com/btc/pushtx/

Is this doable with Electrum loaded on a computer that has been air gapped?

Thanks and cheers!

Topic: Electrum use in AIRGAPPED Computer (Read 192 times)