Electrum 2FA Wallet

[Abdussamad]

You can click on preview to see how much you will be charged. If 2fa is disabled then you are no longer paying trusted coin's fee so that second output to trusted coin's address won't be there.

BTW even if 2fa was enabled what you were paying for is a whole bunch of spending transactions in one go. You can click on the blue shield icon in the bottom right to see trusted coin's fee schedule. To switch wallets go to file > recently open or file > open.

[Listerfiend]

You can click on preview to see how much you will be charged. If 2fa is disabled then you are no longer paying trusted coin's fee so that second output to trusted coin's address won't be there.

BTW even if 2fa was enabled what you were paying for is a whole bunch of spending transactions in one go. You can click on the blue shield icon in the bottom right to see trusted coin's fee schedule. To switch wallets go to file > recently open or file > open.

When I check preview there is the input address and 2 output addresses.  One for the amount I want to send, and one that is about .04BTC.  This is the address
https://blockchain.info/address/3D9kMCEW2MajXy6rXbse6jKCWZvCdTf13D if that even means anything.

I feel like I am losing my mind over this.

[Listerfiend]

WAIT, is the second output my change ?

Original balance
-tansaction fee
-speccified amount asked to be transferred


So is OUTPUT ADDRESS 1 where I want my money to go
and is OUTPUT ADDRESS 2 a new address that is created for the left over amount instead of the original address retaining the difference?

Where is this documented to confirm this and why doesn't the GUI reflect this if this is the case?  I HAVE BEEN SO STRESSED OVER THIS

p.s.  it still says 2fa in the header.  if 2fa is disabled, why does it still say 2fa? 

[HCP]

Because it was generated from a 2fa seed... And it's still technically a 2FA wallet... Ie. MultiSig, you've just disabled The requirement to use TrustedCoin on THIS copy of the wallet as it now contains two private keys, so can sign the "2of3" transactions without using TrustedCoin.

The other output is most likely change... You can tell if the output address in the preview window is highlighted in "yellow"... That equals Change address. Receive addresses should be highlighted in green.

[jerry0]

Hey all notice few threads about 2FA.  Can someone explain this very quickly?  When you set up electrum, they give you option for that?  I don't ever recall it.  Also do most people use 2FA on electrum or not?  Isn't just putting an encryption before you can check your balance good enough?


So if you put 2FA, which 2FA are you using?  Google authent, authy or something else?  So basically if you have 2FA on, that means a hacker cannot hack your wallet?

[HCP]

When you setup a wallet in Electrum, you get the options:

- Standard Wallet
- Wallet with Two-Factor Authentication
- Multi-Signature Wallet
- Import Bitcoin Addresses or Private Keys

The 2nd option "Wallet with Two-Factor Authentication" is the "2FA" wallet option. It is a special kind of "2-of-3" Multi-Signature (aka "MultiSig") wallet that utilises a "third party" service called TrustedCoin.

Being "2-of-3", means that any two out of the original 3 private keys are able to sign a transaction.

The seed creates 3 private keys... #1 is put into your wallet file... #2 is "protected" by the seed and is "hidden" (unless you disable 2FA functionality when restoring the wallet)... #3 is held by TrustedCoin.

The system uses Google Auth "One Time Passwords" (OTP)... so you can use any GAuth app like Google Authenticator, Authy, Authenticator Plus etc...

The idea is, when you want to spend from your wallet, you create the transaction and sign it with key #1... the system then sends the transaction to TrustedCoin... and after you put in the GAuth OTP code, TrustedCoin signs the transaction with key #3... and then gives the fully signed transaction back to you for broadcasting.

The system is "safe" in two ones... one, you get the benefits of 2FA, no-one can spend from your wallet without the seed or 2FA device... and two, it has the safety backup, in that if you lose your phone, or TrustedCoin goes out of business, you can simply restore the wallet with your seed, disable 2FA functionality during the restore and Electrum will put both key#1 AND key#2 into the wallet file, so you can sign transactions without needing TrustedCoin or your 2FA device. (Note: this is meant to be an "emergency recovery" tool, and the idea is you can just rescue your funds and send them to a new wallet.)


You can read more here: https://api.trustedcoin.com/#/electrum-help
and here: http://docs.electrum.org/en/latest/2fa.html