Encryption of Time Machine backups on external disk

comjpf wrote:
I use File Vault to protect my data and Time Machine to back it up to a dedicated external disk.
If my backup disk gets robbed, all my data is readily available to anyone connecting it to another Mac.

No it isn't. The data in your encrypted home folder is what's backed-up.

The Time Machine help states that I can close my session, thus encrypting my disk, then log in as a guest to back up my encrypted disk.

I don't know where you're reading that. You may be misinterpreting the instructions. When you first turn File Vault on, you will be logged-off so it can encrypt your home folder. Thereafter, when you log out, Time Machine will back up your (encrypted) home folder. The normal hourly backups will still run, backing-up changes elsewhere, but not in your home folder (a major disadvantage, many think).

See #25 in Time Machine - Frequently Asked Questions (or use the link in *User Tips* at the top of the +Time Machine+ forum), for details.

Message was edited by: Pondini