quote:Originally posted by SalesServiceGuy:
if you format a HDD immediately twice in a row, it effectively destroys all useable data on the HDD.
Well... Here's the deal. There are two levels of "Format". The most common "quick" format does not actually delete the data, it just forgets where the data is. That data can then be recovered by readily available software.
A "low level" format actually writes over the data. Formatting a HDD a single time this way "effectively" destroys the data.
The problem arises due to the fact that all this "writing" is actually placing + and - charges onto a metallic disk to represent 0 and 1. Even though the disk has been formatted and all the data now says "0", very sophisticated software can actually tell if it was a 1 before. It does this by detecting tiny differences in the amount of electrical charge, though the effectiveness of it has been in dispute.
Here's a good article about this.
Encryption is totally different. In Encryption, the data on this disk is scrambled and you need a key to unscramble it. Losing or deleting the key means the data is "Effectively" destroyed, however, the strength of the encryption comes into play.
If 128-bit encryption was unbreakable, why would 256 and 1024 bit encryption exist?
Still, this is only a concern for spies and nuclear physicists. for "normal" business, one real (not quick) format or ANY encryption would prevent a casual snoop.