Some web applications, like Google Docs, store data generated by the users. Data that can only be read by its owner. Or maybe not?
As far as I know, this data is stored as is in a remote database. So, if anybody with enough privileges in the remote system (a sysadmin, for instance) can lurk my data, my privacy could get compromised.
What could be the best solution to store this data encrypted in a remote database and that only the data’s owner could decrypt it? How to make this process transparent to the user? (You can’t use the user’s password as the key to encrypt his data, because you shouldn’t know his password).
If encryption/decryption is performed on the server, there is no way you can make sure that the cleartext is not dumped somewhere in some log file or the like.
You need to do the encryption/decryption inside the browser using JavaScript/Java/ActiveX or whatever. As a user, you need to trust the client-side of the web service not to send back the info unencrypted to the server.
Carl