To setup two-factor authentication hover over your name in the bottom left corner of the Peerio window and click "Account".
Then click "Enable Two-Factor Authentication" at the lower right side of the Account page.
You will be asked to scan a QR code with an authenticator app. We recommend using either:
Authy: Encrypted backup and sync of your accounts across devices, remote device de-activation, PIN-locking, and a desktop app. Provides convenience and security in the event of a stolen or lost device. Not open source. Available for Android, iOS, Blackberry, Chrome.
If you are using a Windows phone, we recommend using Microsoft Authenticator.
Once you scan the QR code, "Peerio" and a 6-digit code should appear. Enter this 6-digit code in Peerio and click "Authenticate"
From now on, each new day you login to Peerio you will be asked to verify your identity by entering the digits displayed on your mobile authenticator.