<p>For example, take two PC (online, offline) with the last Bitcoin Core.</p>
<p>Online PC has only public keys and the updated blockchain. It will use to watching for balance and create and send transactions.</p>
<p>Offline PC has only public/private key. It will use for sign transactions.</p>
<p>Questions:</p>
<ol>
<li>Is it possible to realize that case with Bitcoin Core?</li>
<li>If yes, How can I export/import the master public key of HD wallet?</li>
</ol>

CC BY-SA 4.0
2021-04-30T09:51:18.647Z
Does this answer your question? [How to send bitcoin from an offline Bitcoin Core that doesn't have a synced balance?](https://bitcoin.stackexchange.com/questions/89962/how-to-send-bitcoin-from-an-offline-bitcoin-core-that-doesnt-have-a-synced-bala)
RedGrittyBrick
CC BY-SA 4.0
2021-04-30T10:06:53.250Z
@RedGrittyBrick this answer gives me part answer my question. Until now I cannot find info about the import/export master public key. Also, I don't know possible it at all. I mean import/export master public key.
B L
CC BY-SA 4.0
2021-04-30T17:47:14.257Z
@BL Bitcoin Core doesn't support exporting/importing master public keys because it doesn't have one (unless you use the experimental new descriptor wallets).
Pieter Wuille
CC BY-SA 4.0
2021-05-01T06:52:37.907Z
@PieterWuille How is it possible? BC is an HD wallet. How I understand HD wallet the first generate Master keys and then simple keys. Or I don't understand something?
B L
CC BY-SA 4.0
2021-05-01T14:44:26.397Z
Bitcoin Core's wallet indeed is an HD wallet (for wallets created after 0.13 at least), but it uses hardened derivation. Hardened derivation does not permit computing addresses from the xpub; it needs the master private key to do so.
Pieter Wuille
CC BY-SA 4.0
2021-05-01T15:22:36.887Z
@PieterWuille I.e. I can't export the master public key. I can export the public keys of addresses. Do I right understand?
B L
CC BY-SA 4.0
2021-05-01T16:13:31.520Z
Not sure I'd call that "exporting"; it's just generating addresses - but yes, if you'd watch all addresses one wallet generates, you'd have a functionally equivalent watch-only wallet. All of this will be much easier and flexible (including support for xpub export/watch, multisig, ...) with descriptor wallets (new in Bitcoin Core 0.21, but still experimental with lots of missing functionality to make it convenient).
Pieter Wuille
CC BY-SA 4.0
2021-05-02T02:43:25.790Z
@PieterWuille Thank you a lot for your explanation.
B L
<bitcoin-core><transactions><wallet><security>
Secure Bitcoin Core
B L
# Secure Bitcoin Core

(Asked by: username_0 on 2021-04-29)

For example, take two PC (online, offline) with the last Bitcoin Core.

Online PC has only public keys and the updated blockchain. It will use to watching for balance and create and send transactions.

Offline PC has only public/private key. It will use for sign transactions.

Questions:

1. Is it possible to realize that case with Bitcoin Core?
2. If yes, How can I export/import the master public key of HD wallet?

**Tags:** bitcoin-core, transactions, wallet, security

> **Comments:**
> **username_1**: Does this answer your question? [How to send bitcoin from an offline Bitcoin Core that doesn't have a synced balance?](https://bitcoin.stackexchange.com/questions/89962/how-to-send-bitcoin-from-an-offline-bitcoin-core-that-doesnt-have-a-synced-bala)  
> **username_0**: @username_1 this answer gives me part answer my question. Until now I cannot find info about the import/export master public key. Also, I don't know possible it at all. I mean import/export master public key.  
> **username_2**: @BL Bitcoin Core doesn't support exporting/importing master public keys because it doesn't have one (unless you use the experimental new descriptor wallets).  
> **username_0**: @username_2 How is it possible? BC is an HD wallet. How I understand HD wallet the first generate Master keys and then simple keys. Or I don't understand something?  
> **username_2**: Bitcoin Core's wallet indeed is an HD wallet (for wallets created after 0.13 at least), but it uses hardened derivation. Hardened derivation does not permit computing addresses from the xpub; it needs the master private key to do so.  
> **username_0**: @username_2 I.e. I can't export the master public key. I can export the public keys of addresses. Do I right understand?  
> **username_2**: Not sure I'd call that "exporting"; it's just generating addresses - but yes, if you'd watch all addresses one wallet generates, you'd have a functionally equivalent watch-only wallet. All of this will be much easier and flexible (including support for xpub export/watch, multisig, ...) with descriptor wallets (new in Bitcoin Core 0.21, but still experimental with lots of missing functionality to make it convenient).  
> **username_0**: @username_2 Thank you a lot for your explanation.  

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## 0 answers

