Selling MBP - How to delete private files

The long version of erase and install does seven (correct me if I'm wrong) erases and then the install?

 

35 is freakin' overkill. I'll bet one pass is sufficient.

 

Be prepared to wait a while for the 35 Pass erase, its major overkill, the government couldn't even retrieve your files after that

 

I recently changed laptops and did the following.

1, Unauthorise your itunes account and backup

2, Delete all absolute unique personal / private files securely via finder 1st. So maybe you have some folders that have personal docs in? Move all to trash then "Secure Delete".

3, Then put the install cd's in and run the disk utility from there.... i think youve said this. I did 7 passes on a 160gb drive and it look 8+ hours so leave it running over night depending on your hd size.

4, Install fresh os.

 

Anything over a single pass is a waste.

 

Why, may i ask?

 

It's a waste because the buyer is, most likely, buying the machine so he/she can use it and not so they can harvest personal data.

If you need more detailed information, check this blog post from a forensic analyst. They started a project to see how many passes are needed to correctly wipe a drive. The consensus is that a single pass is enough.

Synopsis of blog post:

"This study has demonstrated that correctly wiped data cannot reasonably be retrieved even if it is of a small size or found only over small parts of the hard drive. Not even with the use of a MFM* or other known methods. The belief that a tool can be developed to retrieve gigabytes or terabytes of information from a wiped drive is in error."

*MFM=Magnetic Force Microscopy

 

It's been proven now that most data can't be recovered after a single pass. And the data that can be recovered after a single pass is so garbled it's useless. I saw some article about it several months back on Reddit or Digg.

EDIT: The poster above me explains it better. However, I'm pretty sure the article I read was different to his. Same thing though; anything over one pass is pointless.

 

Glad i could help.