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I have a single bitcoin address with all my savings on it. I want to make a paper backup for precaution (as if my hard drive somehow exploded) with that specific address. Is that possible?

Keep in mind that I want a physical backup but at the same time I want to be able to manage the wallet from bitcoin-qt.

emi
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3 Answers3

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Right now, that's not supported. You can try (see user2194702's answer), but if you don't know the exact workings of the wallet, you're very likely to shoot yourself in the foot.

For example, Bitcoin-Qt will send change to a new address every time you create a transaction, and in general does not follow the "balance per address" concept but a "balance per wallet". This improves the privacy of the system (for you, but also for others), but complicates backups. In particular, you cannot backup a wallet by just making a backup of a single key.

HD Wallets (hierarchical deterministic wallets, see BIP32) are intended to overcome this problem, by making sure you can backup a wallet by only making a backup of a single seed that is used to derive all keys. This is planned to be implemented in Bitcoin-Qt, but not yet available.

Flow
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Pieter Wuille
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    Perfect answer! It's a very, very bad idea to make a paper backup of an address then. I've switched to using Armory instead of bitcoin-qt, which does uses deterministic wallets and solves my problem. – emi Jul 01 '13 at 22:00
  • Has there been any recent changes to Bitcoin Core that enable backing up to paper wallet or is it still the same? – M.K. Safi Jun 02 '19 at 01:06
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You can create the backup of the wallet as normally, then use for example bzip2 to compress it. Then you use base64 to make the data printable, then just copy it in openoffice for example to print it (Not to small. Default size should be good). Later you can use OCR software to scan the text again.

Sibbo
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  • An interesting approach. I may give this a shot roundtrip with a dummy wallet and see how it works out. – Robert Karl Oct 14 '15 at 08:33
  • Tested with 7zip, 240KiB instead of bzip2's 351KiB, used word on windows, letter paper, narrow margins, Calibri 10, 58 pages. Am I missing something or that's about the right amount of pages one would get? – Dan Dec 24 '17 at 22:54
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No Problem:

  1. just Export your Privatekey. --> with Bitcoin-QT, go to Console and type: "dumpprivkey {your Public-Address}" - Just replace your Public-Address with that one you want to export

  2. Make a QR-Code from Private-Key & your Public-Address You can use http://www.qrcode-monkey.com/#text But remember: It's not very secure to past your Private-key Online !! Better use some Offline QR Code generator!

  3. Paste your QR Codes (Public Address & PrivateKey) on your Paperwallet

davidduckwitz
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  • This is very KISS, great to know. However you should edit it and warn people about change, as @Pieter said. Specifically tell that the behaviour is the same as paper wallets, and that it doesn't work as a backup. – emi Jul 01 '13 at 21:56