For greater convenience when traveling, if you lose a device, or are switching between devices, Authy supports synching your accounts across multiple devices - phone, tablet and computer. Accounts you have created by scanning a QR code will be encrypted with a password only you know, and the tokens but not the password itself will backed up to the Authy server using the password you selected when enabling backup/sync.
IMPORTANT NOTE: for greater security, this password is not stored anywhere on Authy's servers! If you forget the password and none of your devices are synched, your tokens are lost and you will need to delete them and start over (and you may need to contact the support of services you are locked out of).
Read more about how the tokens are backed up and encrypted on our blog, here.
To enable backups launch your Authy App and go to: Settings > Accounts and turn on Enable Backups as shown below.