Bitcoin Forum
June 20, 2019, 12:51:49 AM *
News: Latest Bitcoin Core release: 0.18.0 [Torrent] (New!)
 
   Home   Help Search Login Register More  
Pages: [1]
  Print  
Author Topic: How to sign bitcoin transaction offline?  (Read 87 times)
allwelder
Legendary
*
Offline Offline

Activity: 1498
Merit: 1000



View Profile
March 18, 2019, 04:33:55 AM
Last edit: March 18, 2019, 06:19:04 AM by allwelder
 #1

With more hardware wallet coming,
How to sign transactions with bitcoin QT wallet offline, or how to send out bitcoin offline?
1560991909
Hero Member
*
Offline Offline

Posts: 1560991909

View Profile Personal Message (Offline)

Ignore
1560991909
Reply with quote  #2

1560991909
Report to moderator
1560991909
Hero Member
*
Offline Offline

Posts: 1560991909

View Profile Personal Message (Offline)

Ignore
1560991909
Reply with quote  #2

1560991909
Report to moderator
PLAY NOW
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1560991909
Hero Member
*
Offline Offline

Posts: 1560991909

View Profile Personal Message (Offline)

Ignore
1560991909
Reply with quote  #2

1560991909
Report to moderator
1560991909
Hero Member
*
Offline Offline

Posts: 1560991909

View Profile Personal Message (Offline)

Ignore
1560991909
Reply with quote  #2

1560991909
Report to moderator
1560991909
Hero Member
*
Offline Offline

Posts: 1560991909

View Profile Personal Message (Offline)

Ignore
1560991909
Reply with quote  #2

1560991909
Report to moderator
PrimeNumber7
Full Member
***
Offline Offline

Activity: 126
Merit: 114

Please no unsolicited “business” opportunities


View Profile
March 18, 2019, 04:48:40 AM
Merited by bill gator (2)
 #2

You will need to create a "watching" wallet within Bitcoin Core that is connected to the internet with your xpubkey, and create an unsigned transaction on the computer connected to the internet, and that has a copy of the up to date blockchain.

You will then need to transfer a copy of the unsigned transaction into Bitcoin Core (QT) from your online computer onto your offline computer, and use Core to sign the transaction. You then transfer the now-signed transaction back to your online computer, and can broadcast it via the command line.

I am not sure I understand how hardware wallets plays into, or is related to your question. AFAIK, hardware wallets are not compatible with QT and they are generally used in lieu of an offline computer. They could be used for the super-paranoid.

Quote from: advert
The forum strives to allow free discussion of any ideas. All policies are built around this principle. This doesn't mean you can post garbage, though: posts should actually contain ideas, and these ideas should be argued reasonably.
Beerwizzard
Full Member
***
Offline Offline

Activity: 518
Merit: 127


Free Crypto in Stake.com Telegram t.me/StakeCasino


View Profile
March 18, 2019, 08:06:47 AM
 #3

I guess it is not what you are looking for but people may use something like physical bitcoins.  Something like this one: https://www.titanbtc.com/physical-bitcoins/
In this case you will get some physical thing with hidden private key on it.
Something like that already has been used in Venezuela when someone issued trade cards with pepe frog on it and you could literally pay with memes: https://dailycaller.com/2017/03/23/venezuelan-currency-slowly-getting-replaced-by-pepe-memes/

NeuroticFish
Legendary
*
Offline Offline

Activity: 1890
Merit: 1238


There are no mistakes. Only opportunities wasted.


View Profile
March 18, 2019, 12:43:37 PM
 #4

With more hardware wallet coming,
How to sign transactions with bitcoin QT wallet offline, or how to send out bitcoin offline?

@PrimeNumber7 gave most of the details you need.
You don't send anything offline, you only sign offline. An online watch only wallet (or certain websites) will help you create the transaction.
You save that transaction, move it with a stick to the offline computer, sign it, go back to the online computer (or certain websites) and from there you can broadcast it.

More details about how to sign the transaction with Bitcoin QT wallet are here: https://bitcointalk.org/index.php?topic=651344.msg7306076#msg7306076



PS. Keeping an offline computer as cold storage is the safest way for storing Bitcoin. Safer than hardware wallets. Make sure that such a computer is indeed offline and remains offline forever.

allwelder
Legendary
*
Offline Offline

Activity: 1498
Merit: 1000



View Profile
March 18, 2019, 01:15:04 PM
 #5

With more hardware wallet coming,
How to sign transactions with bitcoin QT wallet offline, or how to send out bitcoin offline?

@PrimeNumber7 gave most of the details you need.
You don't send anything offline, you only sign offline. An online watch only wallet (or certain websites) will help you create the transaction.
You save that transaction, move it with a stick to the offline computer, sign it, go back to the online computer (or certain websites) and from there you can broadcast it.

More details about how to sign the transaction with Bitcoin QT wallet are here: https://bitcointalk.org/index.php?topic=651344.msg7306076#msg7306076



PS. Keeping an offline computer as cold storage is the safest way for storing Bitcoin. Safer than hardware wallets. Make sure that such a computer is indeed offline and remains offline forever.
Thanks for your explanation and link,that's exactly what I need.
Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!