GreenAddress is a multisignature wallet with improved second factor security. One HD key is controlled by GreenAddress and one key is in your possession. You can use the Ledger Nano (or HW1) to manage your own key. This tutorial will show you how.
Warning: using your Ledger Nano with GreenAddress requires a specific personalization which is not compatible with the Ledger Chrome app. You cannot use both applications with the same hardware wallet.
First, install the GreenAddress Chrome application, and launch it.
Click on "Create new Wallet"
Click on the "use hardware wallet seed", and insert your Nano in the USB port of your computer.
Click on "Set up BTChip" (old name of Ledger Nano). And choose your PIN:
The Nano is ready, and you must now save your seed:
Remove the Nano and insert it on a secure Linux offline computer. It will be in keyboard mode and dump immediately the seed (set the focus on a shell or go in console mode with CTRL+SHIFT+F1).
Once seed has been dumped an secured, plug it back on the GreenAddress computer and click on Continue:
Complete the registration to enable the second factor, your GreenAddress wallet is now ready!
To login back to your wallet, launch the GreenAddress app and insert the Nano in the USB port:
Enter your PIN and confirm:
And you are authentified on your wallet interface:
All transactions will then be securely signed by your Nano and by GreenAddress key controlled by the second factor you initialized.