There is no way to export the seed phrase from a 2FA wallet. If that was possible, it would defeat the purpose of a 2FA wallet.
But in OP, you said that you have the seed phrase.  



Take note that with importing your master public key, you create a watch-only wallet and the fund displayed in a watch-only wallet is not spendable.

You get that error when you have a segwit 2fa wallet and you use one of the master public keys to create a single-signature wallet. You don't get that error when using the master public key generated on a legacy 2fa wallet.
As you can see in the image shared by OP, he/she has used a xpub, not a zpub.

You can get your master private key and gain access to the fund. Just note that you need to use the desktop version of electrum.

1. Go for creating a new wallet and select "Wallet with two-factor authentication."
2. Select "I already have a seed" and enter your seed phrase.
3. Select "disable".
4. Leave the password field empty and click "Next".
5. Find your wallet file in your hard drive and open it with a text editor application. (You can see the default electrum directory in electrum FAQs.)
6. Copy the first master private key. That's in front of "xprv": and above the first xpub.
7. Create a new wallet and select "Standard wallet".
8. Select "Use a master key".
9. Enter the master private key you copied in step 6 and click "Next".

Now, you should be able to spend your fund.

Iancoleman can be used for generating a BIP39 seed phrase and deriving keys from a seed phrase.
What do you mean by a finding a private key? Do you mean you have a seed phrase and you want to derive the private key associated with an address?

The solution is to join a mining pool.

In a mining pool, a group of miners work together with sharing their power over a network and in this way, they increase the chance of finding blocks.
The block reward that is earned by a mining pool is shared among the miners according to the power owned by each of them.

There's a big difference between making such a transaction and creating a time locked address.

When you make a transaction with setting the nlocktime to a future date or a future blockheight, you tell the network that this transaction must not be accepted before the specified time. This doesn't mean the fund is locked and you can't make a new transaction. You can make a new transaction even before the specified time.

Also note that with disabling RBF, you only make the transaction unreplaceable after it being broadcasted and there wouldn't be anything stopping you from making a new transaction before that transaction being broadcasted.
(It may worth mentioning that with full RBF in future, transactions can be replaced by a new one paying higher fee, even if they haven't been flagged as RBF.)

If you use that only for generating a time locked address from your public key, yes. You don't enter any sensitive data for that at all.
You should generate your private key and public key somewhere else using a safe tool (preferably on an airgapped device).

Again, take note that any fund that is sent to a time locked address will be locked until the specified time or blockheight and there won't be any way to spend that before that.
Do this only if you are sure that you won't need the fund before the specified time.

All bitcoin transaction have locktime and in any transaction you make, the nLockTime must be specified. Most wallets set the nLockTime to zero or the last mined block, in the case you haven't specify any locktime.

I think OP is asking if it's possible to spend the fund before the locktime.
If you have set the nLockTime to a future date or a future blockheight, the transaction can't be broadcasted until the specified time or blockheight and for broadcasting a new transaction with the same input(s), you don't have to wait until the specified time.

If you make timelock transaction, that can't be broadcasted before the specified time/blockheight and as long as that transaction has not been broadcasted, there's nothing preventing you from making another transaction with the same input(s).

Take note that it's not true to call this a double-spend. You make the new transaction while the timelock transaction hasn't been broadcasted at all.

Edit:
I don't have any information about the services you mentioned.

If you want to have bitcoin locked for a certain time and there is no way to spend the fund before that, you can create a time locked address.
A tool that can be used for this is coinb.in. Generate a private key and address. After that enter your public key and specify a date or blockheight on coinb.in. It will give you a timelocked address. Take note that there will be no way to spend fund from a timelocked address before the specified time. So, do this only if you are sure that you won't need to spend the fund before the specified time.


You can also create a wallet for your children, make a timelocked transaction to that and give your child the raw transaction. Your child will be able to broadcast that transaction after the specified time.
The difference with the previous method is that, you will be able to make a transaction before the specified time and make the transaction to your child's wallet invalid.
For making a timelock transaction, you can use electrum.

To have full control over your fund, you need to use a trustworthy open source non-custodial wallet, but you don't have to run your own full node.
With running a full node, you can help the network be more decentralized, validate transactions and protect your privacy, but that's not required if your only concern is having full control over your fund.

Bitcointalk Username: hosseinimr93
Utopia Public Key: 30E20017534A3752A8D7E0030294B28222E6D6441E77294317A72BFED290B531
BTC Address: bc1qek4rjx60kyyj8xf0ltu643vwca7rwaqa7teh8j
Message Deep Link (Chat link): https://utopia.im/d53b4431fd604e2f0261792444797aa4?tid=1269852511864789319
Slot No: 98

The other advantage is that we can have numerous addresses all generated from a single seed phrase.


Right. Read the post made by o_e_l_e_o in another thread before.
If you miss 6 words, it would take around 44 million years to brute-force the seed phrase. Even 4-5 missing words can't be brute-forced, let alone 9 missing words.

Thank you SinBad.io for the competition. I was very lucky this time.

Just a question. Wasn't bitcoin price on June, 30 at 10:00:00 AM (UTC) $30,770.53? That's the price mentioned by Sarah Azhari too.
I think you are looking at coinmarketcap's chart on a different time zone.

This wouldn't change my place, but it would make NeuroticFish the first winner and GazetaBitcoin the second winner.

And Congratulations to GazetaBitcoin and NeuroticFish.

What do you mean by being backward compatible?
Take note that it's not that BIP39 seed phrase is the new version of electrum seed phrase or vice versa. They are completely different types of seed phrases.

Almost all non-custodial wallets (with a few exceptions) support BIP39 seed phrase. If you have a BIP39 seed phrase and you know the derivation path, there's nothing to worry about. There are many wallets that can be used for recovering your wallets. (Note that most wallets use standard derivation paths and there is no need to save or write down the derivation path at all)

If you have an electrum's seed phrase, you can recover your wallet using electrum itself and bluewallet. Again, there's nothing to worry about.

I doubt you have any other type of seed phrase.

The checksum isn't the 24th word. The checksum in a 24 word seed phrase is the last 8 bits. This means that the first 3 bits of the last word are determined randomly and the last 8 bits are a function of your 256 bit entropy.
If you have 23 words and don't have the last word, there would be 8 possibilities for the last word.

If the words have been picked truly randomly, right. The point here is that if the words are chosen by human brain, then they are not random.
The correct way to generate a seed phrase is to generate a random entropy using a trustworthy software and then convert that to a seed phrase.

A 24 word BIP39 seed phrase provides 256 bits of entropy while a 12 word BIP39 seed phrase provides 128 bits of entropy. Therefore, the probability of brute-forcing a 24 word seed phrase is smaller. Of course, a 12 word seed phrase is enough and again, take note that human is not a good source of entropy.


There are 2048²³ * 8 or 2²⁵⁶ combinations.
Take note that words can be repeated and the last 8 bits are checksum.

You can't trust electrum, because you can't read the code yourself. I understand you, but what change does it make if the wallet is not SPV and you run your own full node?
Can you read bitcoin core's code and know how the keys are generated? How can you be sure that there is no vulnerability in bitcoin core?

We trust bitcoin core, because it's open source and the code has been reviewed by many people.

I recommend you to avoid any tool that generates the keys through javascript.
click here and read gmaxwell's explanation on why it's not a good idea to use javascript for generating keys.

And it may worth mentioning that if by "without being connected to the internet", you mean just disconnecting internet when generating the keys, that's not enough. You should use an airgapped device.