I'm sorry to be the bearer of bad news: It looks like your funds are gone and the security of your computer is compromised. A quick google suggests that is one of the electrum phishing destination addresses.
You can find more information on the attacks against electrum here: http://electrum-malware.surge.sh/
There's no Expert Mode anymore. The Gap Limit has been hidden from the UI as it was unnecessarily complicated for normal users, and it is not a good method for merchants.
If you need to change the gap limit, enter this in the Console tab and restart the client (Tested with Electrum 3.0):
To view/verify ...
Receiving addresses are addresses generated specifically for sharing with people to send payments to you. Change addresses are generated by your wallet automatically when you send funds to someone else.
To understand how change addresses work, consider this example. Say you received 0.1 BTC once, and 0.2 BTC another time. Now you have two UTXOs (unspent ...
Currently, Electrum is more secure than MultiBit as the MultiBit wallets are not encrypted. The next version of MultiBit, version 0.5.9, supports encrypted wallets. (Disclaimer: I am the lead MultiBit dev)
Security in Bitcoin is related to many things. Here are some of them:
1) Is the code open source and do the developers have a track record ?
Electrum is easier. Armory is harder. Electrum lean towards minimalism. Armory is aimed at power users.
Even though you asked about offline wallets you will likely want to maintain a watch only version of your wallet on your online system to be able to see the current balance, create unsigned transactions and give out addresses to people who want to send ...
It uses m/0/<n> for receiving addresses, and m/1/<n> for change addresses.
Here's some example bitcoinj code to generate receiving addresses from an extended public key.
String serialized_xpub = "xpub.....";
unsigned int address_num = 4;
NetworkParameters params = MainNetParams.get();
DeterministicKey root_xpub = DeterministicKey.deserializeB58(...
There is one more step to actually process the transaction, you have to broadcast it. What you have got is a signed transaction which you can save (& even send to someone else to broadcast).
The signed transaction can be broadcasted like this:
electrum payto <bitcoin_address> <amount> | electrum broadcast -
This will write the transaction ...
As you have suggested, all you need to do is to restore the wallet from your seed on each computer and you'll have all your Electrum instances synced.
Labels can also be exported and imported on each PC in order to avoid having to re-write them; or you can use the plugin LabElectrum (Label Sync) to store them in the cloud and update them at your convenience....
With Electrum 2.x, a wallet can contain either keys you've imported from elsewhere, or keys which are generated (deterministically) by Electrum. You cannot store both types of keys in a single Electrum 2.x wallet.
Since your wallet is of the former type, Electrum will refuse to generate any new keys for your wallet. I suspect the reason for this is to make ...
In fact, the reason Electrum 2.x changed to a 13-word seed* and is incompatible with BIP39 is because they added a version number to the end of the seed. This has the purpose of allowing future versions of Electrum update the seed format while still understanding how to derive all the addresses from previous seed versions.
Standard Electrum seeds have 128 ...
Is it safe to receive funds at this 1FJJd... address?
Kind of. Your wallet knows the private key that corresponds to that address as it is the same private key for the bech32 address. However it does not necessarily know that it should be looking for coins sent to this address, so any transactions that send coins to that address may not appear in your ...
The primary concern with Bitcoin security is where your private keys are stored.
In your scenario the private keys are stored on a Linux laptop which is not unreasonable if you follow good internet hygiene and security practices.
The next best approach is to purchase a hardware wallet from the likes of Trezor or Ledger. These wallets have High Security ...
These are native SegWit addresses, specified in BIP173 using a format called Bech32. They begin with 'bc1'.
Addresses that begin with a 3 are P2SH addresses, an address format that has been around for over 5 years now. They were originally used by multisig wallets like CoPay and GreenAddress, which only saw limited usage. However, SegWit can also be used in ...
With a deterministic wallet you create from an initial seed a sequence of bitcoin addresses. Imagine counting 1, 2, 3, 4, etc.
You can create as many addresses as you like, but not all of them will appear on the blockchain. For instance I might create one especially for you to give me 1,000,000 BTC. That is (alas!) probably not going to be used.
When you ...
For one new wallet type in electrum console:
For 100 new wallets type in electrum-console:
for i in range(0, 100): print wallet.create_new_address(False)
or just (effect after restart application):
There are different "backup-standards".
Some use BIP39 (mnemonic) which lacks of a flexible wordlist and versioning. Its used by Leger, Trezor, Bitpay/Copay, etc.
Electrum uses a different – more flexible – mnemonic backup concept. Though, it's incompatible with BIP39.
But then, there is also the BIP32 keypath which can be different among wallets. Example:...
Secure storage of a bitcoin wallet can only be really considered "mostly secure" if the machine is never connected to any network, and ...
How do I view my extended public key?
Go to Wallet > Master Public Keys, and copy the text that starts with xpub
What are the consequences of giving my extended public key to someone?
They can view all of the transactions and addresses in your wallet. They can generate as many of your addresses as they want.
Can they steal my Bitcoins if I give this ...
Electrum is ordering the pubkeys lexicographically, ie
Note they're all 03, so it's 72=>f5=>f9
In the current version 2.8.3 of Electrum it's very easy to import Multibit wallets (meaning, migrating from Multibit to Electrum). An important reason to migrate is because Multibit (not HD but the classic one) does not allow to change network fees, which makes it very hard or even unreliable to move funds.
Select wallet in Multibit and choose Tools > ...
As Electrum is open-source software, we can probably safely assume it will never go away. That is, even if the devs were to take it off of github etc, there are likely thousands of copies of the source code distributed on the nets. But let's say all the electrum servers were taken down and for whatever reason you couldn't run a python interpretter (not very ...
I've just visited #electrum on IRC to get some advice. While restoring from a seed may make your wallet forget a transaction and allow you to resend it with a higher fee, abpa there told me that this sometimes doesn't work because the server will remind the client about the transaction if it's still in the server's mempool.
abpa suggested using child-pays-...
Electrum uses BIP45.
m / purpose' / cosigner_index / change / address_index
Example for non-change of the first cosigner and first address: m / 45' / 0 / 0 / 0
After a lot of struggle, I found out that Electrum uses following root derivation for normal and multisig wallets. For example:
root/0/0 for each cosigner. Example:
m/44'/0'/0' ==> shared root key (x)
x/0/0 ==> address for first receiving multisig (derive in all cosigners shared keys. all 3 keys must be lexicographically ordered).
some semi-compatible ...
By default, UTXOs are picked randomly.
You mean in Bitcoin Core's wallet? No, they're not picked randomly. There are a number of strategies, but in general the aim is to avoid change if possible, avoid transaction outputs with few confirms if possible, and otherwise create a match close to the amount intended to be sent.
My want to change this behaviour ...
The hourly average fee when this question was posted was between 9 and 10 Satoshi per Byte (sat/B).
The latest TX's that I just randomly checked all had 10.03 sat/B fee which is higher than the 4.5 sat/B that you sent.
Transactions are at a hourly peak right now. Wait it out and it'll probably go through in the next couple of hours as the mempool empties.
According to this FAQ:
In Electrum 2.0, you cannot import private keys in a wallet that has a seed. You should sweep them instead.
If you want to import private keys and not sweep them you need to create a special wallet that does not have a seed. For this, create a new wallet, select “restore”, and instead of typing your seed, type a list of private ...
Electrum servers don't save any private information. All they do is create an interface to a bitcoind instance that is exposed in such a way the Electrum client, which stores the important and private data, can read it.
The only 'evil' thing an Electrum server could do is lying about certain transactions, feeding you misinformation. When you run your own ...