Temp files Vs Value of Secure Erase

Question

Hello,
Let's say I write a "top secret" document in Pages. During the writing process, I save it about ten times. I then print it and use secure erase to delete the Pages document.
So the absolute final version of the document was securely erased, but what about the 10 temporary files that were created during the process?
(For those that don't know, every time you save a document, the system creates a new file on the drive and erases the previous one. This goes on without the user's knowledge. But those are very real files that are erased "normally" during the saving process.)
Loa

Answer 1

Loa wrote:
Hello Pondini,
Thx for the info. I already know about 2 and 3, but they only add to my point: what's the use of Secure Erase?
I only took Pages as an example: everytime you save a document in ANY application, the system deletes the old version and creates a new file. As far as I know, you cannot "modify" any file at the basic data level.
Not necessarily true. Some apps don't even use individual files; they use a large single file or database instead, and they're normally updated, not replaced. Entourage and Thunderbird, for example.
Most likely you'll see it disappear then reappear, usually in an adjacent "location" (i.e. below where the old icon was).
Yes, just like most Autosaves.
But I still don't understand why this is a such a big problem. If you change a file, save it with a new name, then securely-delete the old one.
Or, use FileVault (or, better, put your sensitive documents in an encrypted sparse image);
and/or Zero-out free space.
Perhaps if you told us a bit more about what you're trying to do, we can clarify things.