I guess it would be fairly difficult to make this truly secure without making it too difficult to use. Simply encrypting the data with your Google account passw

I guess it would be fairly difficult to make this truly secure without making it too difficult to use. Simply encrypting the data with your Google account password does not do much good, since you are going to provide that password to Google and they could obviously use that to decrypt the data (should the government request it). One option would be to use separate password for protecting the data, but that would not be very convenient for the user. Very easy to forget such password since you are not going to need it very often.