How creare un wallet Electrum su chiavetta USB
Warning: this method is less secure than the Cold Storage one, and you are adviced to always use that method for consistent sums.
- a normal computer, for everyday use;
- a USB flash drive;
- two sheets of paper;
Download Electrum on the computer following this link https://electrum.org/#download but DO NOT START THE PROGRAM!
Once Electrum is downloaded, disconnect the computer from internet.
Format the USB flash drive and use it only for Bitcoin, don’t use it for anything else. Create a folder inside the USB flash drive, to be used to save the Electrum private key. To avoid any confusion, it’s best not to put any spaces or unusual character in the names. For example, call the USB flash drive “Bitcoin” and the folder “Electrum-Wallet-3.0.1”.
Start Electrum and choose “Auto connect” between the choices to connect to a server.
Once in Electrum Wallet, delete what is written in the “Wallet” string and replace it with the file path of the wallet on the flash drive. If using a Mac, it will be:
In my example, I have used:
Click on “Next”.
Leave “Standard Wallet” selected.
CAUTION: WHAT FOLLOWS IS THE MOST IMPORTANT PART OF THE WHOLE PROCEDURE.
Select “Create a new seed” and then “Segwit”.
The Seed will now appear. The Seed is a sequence of 12 words that will allow you, at any time, to recreate the wallet and recover your Bitcoins, even if the computer you’re using became lost or destroyed.
WRITE THE SEED ON THE TWO SHEETS OF PAPER, BY HAND, WITHOUT USING THE PRINTER AND WITHOUT USING THE COPY AND PASTE FUNCTION. KEEP THE TWO SHEETS OF PAPER IN TWO DIFFERENT HOUSES, AS A HOUSE CAN BURN DOWN OR BE FLOODED. LOSING YOUR SEED IS EQUIVALENT TO LOSING YOUR BITCOIN.
IF THE SEED HAS BEEN COPIED AND SECURED WE CAN PROCEED INSERTING IT IN THE CONFIRMATION WINDOW.
In the subsequent window, we will be asked to insert the seed. This must be typed by hand, because the copy and paste functions are disabled as a security precaution. Insert the seed copying it from the sheets you have just written and proceed. Just to make sure to have driven the point home: the Seed is fundamental to recover the Bitcoin in any case. Pay maximum attention to its storage.
Insert a password to encrypt the wallet. If this password is forgotten, the wallet can be regenerated anyhow, thanks to the seed. It’s always best to choose a complex password.
Now the offline wallet is set up. Now you must generate the public key that you will use on the online computer for all the rest. To do that, click on the “Wallet” menu and select “Information”.
You will see a string of letter and numbers starting with zpub. This string must be copied and pasted in a txt document that will be saved on the Desktop, since this string will be used on the everyday use computer, the one that will be connected online.
You can now close Electrum, eject the USB flash drive and reconnect the computer to the internet.
Start Electrum again. The software will start with the basic configuration, since the wallet you have just created doesn’t exist anymore (it resides on the USB flash drive that you have just removed).
Select “default_wallet” in the first screen and “Standard wallet” in the second. In the next screen, select “Use public or private keys”.
Insert the public key previously saved on the Desktop.
The online wallet has been set. You will get a warning about this wallet being “watching-only”. This means that the wallet can’t send transactions, but only receive payments. That is correct: this wallet lacks the key for the signature that is stored in the USB flash drive.
To receive Bitcoins, you just have to go to “receive” and use the address given in the first string (marked “Receiving address”). It is possible to add a description to the address and to save it for future uses. You can also associate a expiry date to the address. The address doesn’t expire and will always be available to receive Bitcoins. The expiry date will only be useful as a reminder for the person who receive the address, signalling that you expect the payment before that date.
To send Bitcoins, you need to create a transaction on the computer, clicking on “Send”, inserting the address you need to send the Bitcoins to and the amount to pay. You also need to select the fees for the miner, according to the needed speed of the transaction. After that, you can click on “Preview”.
The transaction cannot be signed. That’s why the “Sign” button is disabled. For this reason, the transaction needs to be saved and put on the desktop.
You must now disconnect the computer from the internet and insert the USB flash drive. Select “File” -> “Open” from the Electrum menu, selecting the wallet created at the begin of the procedure, on the USB flash drive (it should also be available in “File” -> “Recently Open”). Once this wallet has been opened, go to “Tools” -> “Load transaction” -> “From file” and select the transaction you have just saved on the desktop.
Electrum will realize this is a transaction needing a signature and will prompt you to do so. After that, you need to save the signed transaction on the desktop. You can close the wallet in the USB flash drive, eject the flash drvie and reconnect the computer to the internet.
Load the signed transaction on the Electrum wallet on the Desktop (the watch-only one) from “Tools” -> “Load transaction” -> “From File” and click on “Broadcast”, once loaded.