Select Help (to the right of Settings)
Select Debug Window
If you encrypted your wallet, unlock it by entering walletpassphrase "YourLongPassphrase" 600 next to the > input box
Next to the > input box type importprivkey <bitcoinprivkey> (Note that the private key must not have spaces, remove them if they are included in ...
Copy your public receiving addresses from Bitcoin-Qt.
Go to the Bitcoin-Qt console: click Help/Debug Window and then select the Console tab.
Run walletpassphrase [your password] [timeout in seconds] to unlock your password protected wallet.
Run dumpprivkey [Receiving Bitcoin Address] for each receiving address to be migrated to MultiBit. There ...
Importing a private key can lead to non-intuitive behaviour, and that can be exploited by an attacker.
Imagine I'm evil. I give you a paper wallet with 1 mBTC on it. You're happy and import it. I keep the private key and wait. Depending on the client/user, maybe someday you'll put some real money on there as change/received funds. Then I can swipe them ...
Key import by itself (from a trusted source of keys, such as your own cold storage or backups) isn't a dangerous thing. However, the vast number of ways one can cause problems for themselves through key import leads to these warnings.
Many such warnings appear to address more complex situations beyond bitcoind's scope. In this case, there can be many ...
Here is one way to do it without the "command line geeky stuff".
Visit https://blockchain.info/wallet/import-wallet. Drag the Bitcoin-Qt wallet.dat file into the dotted area. Follow the instructions.
Login to the new wallet. Under the Backup heading click download.
Open multibit choose Tools -> Import Private Keys. Now import the wallet.aes.json file just ...
1.) The web page at BitAddress.org can be loaded from a file on a thumb drive or other storage. Most browsers let you save the web page using a View Source (right click maybe), and then Save File to a thumb drive.
Then from the offline computer you open the file from the browser and the BitAddress page will load.
2.) The private keys don't expire or ...
For those of you looking to import your Vanity address into your BitCoin QT client, here are the instructions (source):
Backup Your Wallet
Although this process is well tested and used you should always take another backup of your wallet.dat file before starting.
Open Debug Window
Then go to menu: /Help/Debug Window and click on the tab - Console.
If you are downloading the blockchain from scratch I strongly recommend using the bootstrap.dat file, which allows your computer to simply verify blocks and import them without needing to download for days or even weeks on end.
The main issue with downloading from the network is that your client will only download one block at a time. It starts with block #...
You ought to ask this question on CryptoSE, as the problem is not Bitcoin-specific. I've even done that for you.
The public key is QA=dAG where G is the base point on the curve defined in the publicly agreed upon parameters.
And you can find the Bitcoin curve (secp256k1) parameters in the wiki.
There is no way to 'un-import' a private key in the core client. What you could do instead is:
Make a list of all the private keys you do care about.
Close your client.
Move the wallet.dat out of the data directory to some other location.
Start the client.
Re-import all the private keys that you do want in your wallet.
This is sort of a work around, and it ...
The RPC interface doesn't generally provide any "batch mode" functionality. If you want to import 100 addresses, call importaddress 100 times. You might like to write a short script with a loop in some other language.
You should set the rescan parameter to false for all but the last address, so that you don't trigger rescanning 100 times.
Copy the blockchain.dat file into your bitcoind directory, and the application will begin processing the file, checking for validity as it goes. Once it parses the entire blockchain file, it will connect to peers to continue downloading more-recent blocks.
It does not answer your question of getting your private keys out of bitcoin-qt, but this link explains how you import a single private key into MultiBit:
If you have more than one private key it is simply more rows in the import file.
The date alongside each key is a bit non-obvious. It has to be before the ...
Have you looked at references of http://en.wikipedia.org/wiki/Elliptic_Curve_DSA
Certicom Research, Standards for efficient cryptography, SEC 1: Elliptic Curve Cryptography, Version 2.0, May 21, 2009.
I think the core of the problem is that we call base58-encoded public key hashes "addresses", no matter whether people are willing to accept payments to them.
In my opinion, they are just identifiers for a public key - something internal in Bitcoin's technology. Humans shouldn't ever see them, unless they are debugging.
Satoshi originally didn't intend to ...
You can ask the vendor for the transaction id of the transaction where they sent the bitcoin to you. Look it up on https://blockchain.info to check it exists and is sending bitcoin to your receiving address correctly. Look at the date of the transaction. Go into MultiBit, select your wallet and choose the menu option 'Tools | Reset blockchain and ...
Yes. txindex=1 is not related to the wallet and the wallet does not know about the txindex nor does it care. What the wallet really cares about is transaction output information and which transactions are related to addresses stored in the wallet. The txindex does not store any of that information, all it stores is the location of each transaction identified ...
Notice that your private key retrieved from the Satoshi client begins with a K. According to the List of Address Prefixes, that means the key is exported in compressed form.
MultiBit's export file saves private keys in uncompressed form. Private keys in uncompressed form begin with a 5.
You can divine the uncompressed key using Bitaddress's wallet details ...
Yes, you can send coins to this new address. If you restart your client you'll see the address will have moved to your receive list of addresses.
The new address initially posts in your address book because of the need to scan the blockchain for all transactions associated with that private key. But you have to actually restart your client to move the ...
Step one : Update your Multibit, normally since 0.3.4 it can import Blockchain.info
Anyway, if it's not working you can try this :
Go to Import/Export in Blockchain.info
Now "Export Unencrypted", change Base58 by Bitcoin-Qt format and take the key after "priv".
Now go to ...
Set the date in the import file to the date the key was created (date and time are in UTC, not local time). Then do Tools -> Reset block chain and transactions. This will cause MultiBit to rescan the block chain from the earliest key creation time. It should then show your transactions.
Unlock your wallet
Run Import Command in Debug Window
Sweep to another key
Tools needed: camera in your PC + qr code reader.
But of course you can find the private key value with classical mathematics ;)
To supplement George's answer:
It would help if you would clarify what you mean by "crash" and describe exactly what happens. (To many people, "crash" means a segfault or similar abnormal termination, but it sounds like that's not what you mean.)
If the issue is that the program appears unresponsive, this is normal: it's a well-known annoyance (perhaps ...
Perhaps a distinction between importing and sweeping a key needs to be considered. The aforementioned warnings deal with the importing of keys, and does not refer to the sweeping of keys, which moves all the coins to a new address. This method is inherently secure.
importmulti finds the earliest of the timestamps, and rescans from that point after all imports are done, yes. The wallet stores metadata about keys including the timestamp, which is why a timestamp is provided individually for each address rather than a single timestamp overall. Other commands like dumpwallet export a timestamp per key as well so this makes ...