The Great Zero Challenge Remains Unaccepted

An anonymous reader writes "Not even data recovery companies will accept The Great Zero Challenge and only four months remain! We've all heard how easily data can be recovered from hard drives. We're told to make multiple overwrites with random data, to degauss drives and even physically destroy them just to be extra safe. Let's get the word out. The challenge is almost over! It's put up or shut up time. Can you recover the data?"

Comments

Re:Do many companies really do EFM recovery?

[anagama]

Although the drive has to be in a living system and not on the shelf, it's worth noting the cold boot attack: http://citp.princeton.edu/memory/

Q. What encryption software is vulnerable to these attacks?

A. We have demonstrated practical attacks against several popular disk encryption systems: BitLocker (a feature of Windows Vista), FileVault (a feature of Mac OS X), dm-crypt (a feature of Linux), and TrueCrypt (a third-party application for Windows, Linux, and Mac OS X). Since these problems result from common design limitations of these systems rather than specific bugs, most similar disk encryption applications, including many running on servers, are probably also vulnerable.

An urban legend

[Ancient_Hacker]

It's an urban legend. You can't recover erased bits. If you could it would imply that you can store at least two bits in the space of one. Disk companies have a pretty good idea what their heads and surfaces can do. Do you think they'd be passing up big $$$ by under-utilizing their disk's capacity?

There is that one Usenix conference "paper" foating around out there, but if you read it carefully it does not give a single example of one recovered bit.

If you've ever looked at the waveform coming off a disk head, you'd wonder with all the x/y noise and jitter how they can get even ONE bit out of that hairball. The answer is, they can, just barely, by applying all the sync, gating, PLL, and deglitching tricks, just barely reliably recover bits at the maximum recording density possible.

And all those pictures they show of bit patterns lingering under large erased areas are actually counter-examples. They prove that you can detect periodic bit patterns under large erased areas. Duh. In the real world the underlying data is not periodic, and the erasure isn't smooth or periodic either. If you overwrite real typical data with random data, you can't recover the original data. Shannon and company, you know.