Authy is a free mobile / desktop app for two factor authentication, as well as security partner and SMS delivery service of many websites that want to make two-factor authentication work better for their users. Some of our well-known partners include CloudFlare, Coinbase, Twitch, Humble Bundle, Mercado Libre, etc. If you set up an account with one of those companies, and use two-factor authentication, that company may use Authy to send SMS to your phone, and if so, they have created an Authy account for you to use with our free mobile apps if you wish.
Passwords aren't great. More and more, email hacks or phishing attacks leave users vulnerable to unauthorized password resets. Two factor authentication dramatically increases your security by requiring entry of a code visible only from your mobile or desktop device, sent by SMS or an app that syncs with the website you are accessing.
Some advantages of the Authy apps:
- Your data can be backed up to Authy's server if your phone is lost or stolen - and afterwards, you can log out the old phone, too (settings: remove device).
- You will receive a push notification if someone else is trying to access your account via SMS. High risk accounts (such as Bitcoin) will require a 24 hour delay with email approval, or you can turn on this protection by disabling "multi-device" in the Authy app settings.
- You may sync multiple devices to one account - even copy and paste a token right from the desktop Authy app into the website you need to access.
- If you are traveling, the app doesn't need an SMS with roaming charges... just use the code generated in the app.
- If you have changed your phone number but didn't update your information with the websites you need access to, you may use Authy's account recovery tools to change your number.