Transferring bitcoin from old bitcoin core wallet to electrum

I have a 7 year old wallet.dat file that was created by the bitcoin-qt program (https://bitcoin.org/en/bitcoin-core/).

Downloading the blockchain takes too long and I experienced that the downloaded chain risks getting corrupted. I decided to use Electrum so I can access the wallet’s contents sooner.

I tried following the steps from https://en.bitcoin.it/wiki/Transferring_coins_from_Bitcoin-Qt_to_Electrum, but I’m stuck at the step dumpprivkey, because I don’t know what <your bitcoin address> means. I have installed a new bitcoin-qt version so naturally the list of receiving addresses is empty.

I have also tried another approach with dumpwallet. This yields a 250 kb file with thousands of lines and I don’t know what to do with that. Surely importing every single private key from that file isn’t feasible?

How does Electrum get transaction input values?

https://electrumx.readthedocs.io/en/latest/protocol-methods.html#blockchain-transaction-get defines the api for getting txs. Vin values are not included, however. Is it possible to find these without querying for every txid? Is that what Electrum does or is there an easier way?

How to transfer BTC from desktop wallet to mobile wallet (without fees), say using Electrum or Bitcoin Core

I have both Bitcoin Core & Electrum wallets installed on both my desktop & mobile. How do I transfer BTCs from respective desktop to mobile wallets (& vice-versa) directly (i.e., not thru the blockchain) to avoid fees?

electrum – Issue with broadcasting the transaction

Hi I got an issue as I can’t get my refund back on coinb.in . I don’t really understand the whole thing as I have never used that before. It’s a multisg 2 of 3 (if that means anything to you).
I did verify it then I signed it and copied the text fron the green box, but when I try to broadcast it it says “there was an error subbmiting your request. Try again”

Also tried to get this done through electrum wallet but when I go to broadcasting it says “opeation not valid with current stack size”
Can anybody help please, whoever helo me willl recieve a reward

How to open lightning network channel to a selected node in Electrum?

Electrum (version 4.1.2) Open Channel dialog only contains a dropdown "Trampoline" with predefined entries. How a new channel can be opened to a specific node?

Electrum Open Channel Dialog

How do I double spend using electrum for fix unconfirmed transaction

I have two Blockchain.com wallets.(Both of them are mine)
Some days ago i did a big mistake.
I sent 1100$ From wallet #1 to wallet #2. (10.0 sat/vB > As you see this is very very low) (TX LINK)
And i sent that 1100$ to my friend from wallet #2 after the transaction upper immediately. (99.3 sat/vB) (TX LINK)
Because of low fee in first transaction, both transactions have n’t confirmed yet.
I asked people to fix these unconfirmed transactions.
They told me use another wallet like Electrum wallet and double spend those unconfirmed transactions.
So i installed Electrum in my windows 7 os.
For double spend using electrum i found this link :
https://steemit.com/bitcoin/@profitgenerator/tutorial-how-to-fix-unconfirmed-transactions
But it seems it has deprecated.
I could n’t understand one part of this tutorial :

Re-create the transaction, but this time put a higher fee.
Sign your transaction, and save it to a file, it should end with .txn extension

My questions :

  1. As you know Blockchain.Com has no RBF option. So those two transactions have n’t RBF flag.
    In this situation can i use double spend with electrum?
  2. How can i create a transaction in offline mode and sign and save it?
    I tried it.But after setting fee and click send button electrum tried to broadcast.And i could n’t find an option for sign or save transaction with .txn ex.
    Would you please share a complete step by step tut about this.
  3. If i double spend first transaction what happen to second unconfirmed one? (I am a bit confused about this)
  4. Should i double spend two unconfirmed transactions with two temp wallets in electrum or double send of first one is enough?

Why does Electrum include seemingly unnecessary inputs in a transaction?

I want to make a payment of x BTC.

My Electrum wallet shows two “output points” in the Coins tab (with the same address). Both of these show an amount much larger than x BTC.

If go to the Send tab and start to make a payment to an address, then click “Pay…” and then “Advanced”, I can see two inputs, which seem to correspond to the two “output points” in the Coins tab and show the same amounts. The transaction size is 447 bytes. I abandon this transaction.

If I go to the Coins tab, right click on one of the two “output points” and choose “Spend”, Electrum shows a green banner saying “Coin control active”. If I start to make the same payment, the “Advanced” dialog now only shows one input and the transaction size is 226 bytes.

This looks to me as though I can make the same transaction and incur a smaller fee by using “coin control”. Am I missing something? Is there a disadvantage or risk to doing this? I’m thinking there must be, otherwise Electrum would just do it automatically.

I could understand needing two inputs to the transaction if x was more than the amount associated with each one of my two “output points”, but it isn’t.

Thanks!

How to accept Bitcoin payments using Bitpay and Electrum for a business

Our company uses a standard invoicing model where we bill our clients the service charge and require payment within X days. We’d like to be able to add a “Pay with Bitcoin” option on the invoices. We are thinking we’d use a service like Bitpay to facilitate the payment and then have Bitpay send the BTC to our business wallet which uses Electrum.

What are some important considerations? Although Electrum generates several wallet addresses, Bitpay only allows entering a single address. Is this okay? I’ve seen recommendations to always use different addresses, but I can’t figure out how to do this with Bitpay.

Perhaps another service instead of Bitpay would be a better option…

transactions – Sent money from Bitcoin Core to mobile Electrum and for 3 days can`t recieve it

3 days ago I made transaction from my Bitcoin Core to my mobile Electrum but I didnt receive the money yet. I cant see this transaction in Electrum and on Blockain,Tradeblock either, however, Bitcoin Core shows that the money are sent. Usually I can see my transactions in Blockchain and Electrum but that doesn`t work with that transaction at all. There is definitely a problem with the app Bitcoin Core.

Who knows how I can receive money?

How does Electrum compute seed byte just before BIP-32?

As a newbie in Bitcoin and programming it, I am trying to generate BTC addresses from mnemonic. So I read about the BIPs, and found codes in Github that implement those.

I found out that Electrum doesn’t implement BIP-39 (by default if I have not mistaken), because mnemonics that are invalid in BIP-39 are accepted by Electrum!

So my question is: How does Electrum do its own “From mnemonic to seed” section (atleast for standard wallet)? This “seed byte” is the one to be used in BIP-32 for generating keys, if I have not mistaken.

I tried the following Python psuedocode (from “Electrum Seed Version System”):

hmac = hmac.digest(b"Seed version", b"...(12 word mnemonic)...", hashlib.sha512)
bip32_thing = Bip32(secret = hmac(:32), chain = hmac(32:)) # default: Bip32 main net version (idk what this means)

But my generated master public key and Electrum’s doesn’t match (most likely I misunderstood the “Seed Version System” altogether). Thanks for responding!

In case it helps: I am using bip-utils in Python.