Understanding encryption using Disk Utility
Using Disk Utility, I created an encrypted disk image, into which I have copied files I would like to secure. This works well, but I am trying to understand how things work, so that I can control exposure. Fundamentally, the question is when are files exposed, and when not. Clearly, when a password has been entered, the file is visible and available. But is it being decoded (ie is the underlying file is always encrypted)? If I make a copy of a file (after password entered), is this copy encrypted? If I make a back-up using Time Machine, are the back-up files (of encrypted files) encrypted?
Mac OS X (10.7.2)