How To Run Ian Coleman's BIP39 Tool In A Secure Offline Ubuntu 16.04 Temporary Live Boot Session
This article assumes that you have completed the previous guide on setting up an Ubuntu 16.04 temporary live boot session including running 'sudo apt-get update' and installing git from the official Ubuntu software repositories. The task for this article is to safely download Ian Coleman's BIP39 Tool directly from Github so we can run it from the local machine while it is disconnected from the internet.
It is important we go through these set of steps rather than using the tool via the web in order to keep your private keys somewhat in a state of cold storage where they don't touch a machine that is on the internet. We will not use Google or other service (that may be tracking you) to download the tool. Instead, we will download it directly from its source.
Your seed phrase will not be typed into this machine until it has been disconnected from the internet. Since by design, the OS will not write anything to the hard drive, it will not retain any memory of the keys (unless there is highly-sophisticated malware that evades these precautions). This is appropriate for low-value amounts where the ease of using Ubuntu provides better utility than no protection at all. For higher-value amounts and more confident Linux users it is recommended that one take a look at using TAILS instead.
Download the BIP39 Tool From Github
For the last step of the previous article the previous article, git was installed. The first step here is to use git from the Terminal application to clone Ian Coleman's repository (https://github.com/iancoleman/bip39) from github onto the local machine. This can be done by typing 'git clone https://github.com/iancoleman/bip39' into the terminal and press 'Enter'. It will take a couple seconds look like this when it is done:
This downloads the source code provided into the Ubuntu user's home directory. Since this is a temporary live boot session, this is not actually written to any disk, but rather just held in the computer's RAM for the remainder of the time the PC is powered on. However, it does function as if it were on a hard drive as far as the software can tell.
We can now close the Terminal window, and open Ubuntu's GUI File Explorer tool by clicking on the grey icon of a file cabinet on the left hand side menu. In the window that comes up, you should see a folder called 'bip39' which is the first item in the user's home folder. If you double-click on it, the file explorer shows the contents of the folder which should look like this:
Disconnect From the Internet
Before we run the tool, we should disconnect from the internet. Ubuntu's network control menu is in the top right conner. Networking can be disabled. Additionally, to be completely sure you are offline, you can consider unplugging your computer's Ethernet cable (if it is connected that way) or switching off any hardware networking disabling switches if, for example, you have one on the laptop you are using. What you see in the menu will vary depending on your network hardware, but this is what the menu looks like:
Open The BIP39 Tool With Firefox
The tool should appear in the web browser. You can now do stuff like enter your BIP39 seed phrase to derive your associated Bitcoin private keys:
Once your passphrase is entered, you can use the tool to examine the possible key derivation paths for addresses and private keys associated with your mnemonic phrase in a safe environment.
When you are finished with using this tool, you can close the Firefox window, and shut down the PC. It will not retain any memory of what was done during this session.