Lion brings a slew of new features and interface changes. Some drive me mad: reversed (“natural”) scrolling—thankfully, that can be disabled. But some are great, like the ability to encrypt your Time Machine back-up.
I don’t have a real need for serious data security measures, but if you back up wirelessly, your back-up is vulnerable to unauthorized access even if you’ve secured your wireless network with a password.
If you need this added measure of security, open System Preferences from the Apple menu and click on Time Machine. In this preference pane, click Select Disk, select the disk you’re currently using for back-up, and click the box labelled “Encrypt back-up disk.”
Once encryption is enabled, Time Machine will take many, many hours to encrypt your back-up, and if your back-up disk is accessed wirelessly, your encryption time will go up substantially.
If interrupted, you run the risk of corruption, so plan to leave your computer on and connected to your back-up disk for quite some time once this process starts. I recommend you connect to your network by ethernet to maximize throughput in the encryption process.