5

Is this considered safe enough? Nothing is "safe enough" if we do not know the cost. OK, if you have $100k in bitcoins the 12-words phrase is safe enough. If the 12-words phrase is the seed to the "Method of destroying the Universe" I would recommend to add at least 11 bits of entropy and use 13 words.


5

I don't know if this is the recommended way, but I did this by using the Send Nxt API call on an offline computer, storing the transaction bytes, and broadcasting the transaction from an online computer by using the Broadcast Transaction API call.


5

Electrum uses AES-256-CBC to encrypt wallets. The key is sha256(sha256("your password")). Electrum wallet source: https://github.com/spesmilo/electrum/blob/master/lib/wallet.py slowaes library: https://code.google.com/p/slowaes/source/browse/trunk/python/aes.py


5

If you have encrypted your Bitcoin.org wallet with a passphrase, then only having that passphrase will allow that to be decrypted. If you have a backup of your wallet prior to performing the encryption step, then any coins from that wallet that still have not been spent can be recovered. Otherwise, without that passphase to open the wallet you cant get to ...


5

The chances of someone "brute-forcing" or guessing your seed is extremely slim. There are more than 5 duodecillion possible combinations of twelve-word seeds. Just so you get an idea of how big that number is, it's more than 1 thousand million million million million million million possibilities.


4

There is a script provided by a forum user Revalin which can be used to attempt variations. There is a forum user Rix who may be available for hire to provide assistance with this type of problem. You can also try out this script: https://bitcointalk.org/index.php?topic=170694.0


4

You can dump your old wallet to a backup file, restart the program to generate a new wallet and import your old wallet into it. Assuming you are in the directory where your wallet file is located, using the command line that would look like this: bitcoind walletpassphrase "xxx" 60 bitcoind dumpwallet "wallet.dat.backup" bitcoind stop mv wallet.dat wallet....


4

A very, very long time. Oxford English Dictionary contains full entries for 171,476 words in current use. If you use only lower case letters and they are mostly random words (no phrases - "four score and seven years ago" is like having your password be "secret"), there are about 7.47e41 possibilities. At 50 million attempts per second, it'll be about 4....


4

The wallet actually uses a randomly generated master key to encrypt the keys, and this master key is encrypted using your passphrase. When you change the passphrase, all that changes is the encrypted master key. The actually encrypted wallet keys aren't touched at all.


4

The passphrase is stored as part of the wallet.dat file, so yes, that should work, as long as you haven't received any payments to addresses with private keys that don't exist in the old wallet. Note that these received payments can actually occur when you send a payment, as a hidden "change" amount is sent to an unused hidden private key which is stored ...


4

If your passphrase contains spaces or special characters, you will need to wrap it with single quotes (') so that the debug console can properly parse your passphrase. For example, if your passphrase were This is my passphrase, then your command should be walletpassphrase 'This is my passphrase'


4

Is there a way to just manually transfer the btc from the old wallet into a new wallet we do have access to No. You need at least one of the things you have none of working wallet. PIN or password for the wallet. Recovery phrase for the wallet. is there any way to extract the password or private keys directly from the wallet file? No. The brute-force ...


4

What can I do? You could find tools that automate the trying of various combinations of seed-words. Some are mentioned in similar questions here. For example btctools, btcrecover. Use them or adapt them to your needs. Lost my Bitcoin wallet and have only 11 out of 12 mnemonic seed phrase words. How can I get my Bitcoins? Need help to recover blpckchain....


3

Multibit will prompt you for a password regardless of whether you are sending it to your own wallet or not. This is by design, since if it didn't do this, it would allow anyone who can access your laptop to transfer bitcoins from your encrypted wallet by sending it to the unencrypted wallet first. Sorry but unless you made an unencrypted backup of the ...


3

If your wallet hasn't been compromised (how can you be sure?) then it should be enough to secure it with a strong passphrase and then be sure to back it up. If your wallet has been or even just might have been compromised then securing it with a strong passphrase now might not be enough. Sending the Bitcoins at risk to a new address in the same wallet ...


3

Bitcoin-qt only asks for your password when you do an operation that requires it, such as sending coins. Currently, wallet.dat must be called that and reside in the Bitcoin data directory. It might be possible to use symlinks to work around that.


3

In particular, is there a way to make it so that it is impossible to know if a transaction signed with a password is correct unless its part of a mined block? This way, even if your password only requires 1,000,000 tries to crack, the attacker needs to mine 1,000,000 blocks to bruteforce the password? I'm not aware of any cryptographic constructions that ...


3

No. The whole point of strong encryption is that it is impossible to recover the data without the passphrase. You can: Keep trying to brute force (maybe with faster computers, or a better initial guess at the passphrase) See if you have a backup of the wallet.dat file that isn't encrypted Try really hard to remember Give up, and resolve to be more careful ...


2

Blockchain.info does not use 2FA for encrypting the wallet and instead uses it only for limiting access via the web interface. If your system is compromised with a keylogger, and the attacker has access to the blockchain.info wallet (e.g., the backups sent via e-mail), for instance, then the attacker can perform a replay attack and spend the funds from the ...


2

It is all a matter of how many bits of entropy your passphrase has (how hard it would be to guess). Using a couple words provides a lot more randomness than a couple random characters. As far as I remember, the algorithm used to encrypt the private keys that is used by BitcoinQT has about 100 bits of security (which is a lot). You would want to attain a ...


2

No, bitcoin core does not expand environment variables in bitcoin.conf. See here to see how options are parsed. You can expand environment variables as arguments for bitcoind: $ bitcoind -rpcuser="$RPC_USERNAME" -rpcpassword="$RPC_PASSWORD"


2

No, because the encrypted keys don't change in that case. When you encrypt a wallet.dat file, a random master key is generated, the master key is encrypted using your passphrase, and the actual address keys are encrypted using the master key. When you change the passphrase, only the encrypted master key is changed.


2

However, have never had the option of providing a passphrase. You must certainly have set a passphrase in the past. There's no way to remove it without knowing exactly what it is. If you can not recall what password you set, your funds are lost.


2

The wallet passphrase is there to protect the wallet file on disk. It is not an authentication mechanism or a security measure against anyone who can see what is sent to it. It does however prevent private keys from hitting disk in readable form.


2

Yes, any person you give your rpcpass and rpcuser to can control your wallet, that's not what the wallet encryption password designed to protect against. You really don't want to be giving arbitrary users your RPC authentication details under any circumstance, and I can't think of one where you would need to.


2

That is certainly weird and it's most likely that you simply are typing a different password. To test this hypothesis, install MultiBit on another computer and import your wallet to see if it works. Perhaps your local MultiBit instance is corrupted. Another option would be to try different versions of the client, although the wallet encryption algorithm ...


2

In short: 12-word seed has enough entropy to be safe against brute force attack. First of all not all 132 bits are random. Seed uses some kind of control sum. Lets talk about 128 bits of entropy. Lets imaging the following attack: We will take one billion (10^9) of the most powerful mining hardware in 2017 (13 TH/s each). We will make a 1000 years brute ...


2

There is a copy of the password stored encrypted with an AES key derived from the wallet words. Thus if you forget your password and still have a copy of your wallet you can use your wallet words to recover your password.


2

So just like Nick said, If the encryption is done using 256 bits then creating a passphrase which is 512 bits long would be the same as creating a passphrase which is 256 bits long (as long as its random). You should look into brainwallets as they provide a way to create strong passwords which are also easily memorable since all you have to memorize is a 3 ...


2

Might want to experiment with libbitcoin's command line interface called bitcoin explorer (bx). Instructions for using v3.0 bx commands used below are found here in the right pane. Assuming there is no mnemonic password, and the associated public key is compressed, the associated BIP 32/39/44 m/44'/0'/0'/0/0 private key and address can be computed as ...


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