I do not normally keep any Google account details on my Android device. I'd normally log in to Google Play weekly, update my device, and then delete my Google account details from my device.
When I do log into Google Play, the "Google Services" page asks me to accept (or not) an offer to "Use basic device backup". The explanation says:
Easily restore your data or switch devices at any time. Your backup includes apps, app data, call history, contacts, device settings. Your backups are securely encrypted and uploaded to Google ..."
I have always declined the request without much thought but for the first time today I read the latter part of the description which brought to mind the following questions:
Is the information securely encrypted on my phone prior to the encrypted backup being stored by Google, or is Google saying that they will encrypt the backup? If it's the former, and the encryption is done on the device, then how is it possible to transfer the information to another device? Where is the decryption/encryption key that would enable the new device to use the backed-up data?
Is "backup" the same as "sync"? More particularly, if I backup the various apps (calendar, messages, contacts, etc) is the effect the same as syncing my device calendar with a Google calendar?