I take a pretty serious interest in things related to data-security, simply because I find the whole subject interesting. I'm always looking into new ways to hide, securely destroy or encrypt data. I was recently playing around with a few new ideas. I'm now satisfied that this method will annihilate data beyond any doubt, with no remote possibility of having it recovered by any means - current or future.
You will need:
- A data-recovery tool. This guide will reference Piriform's "
Recuva."
- A volume-encryption tool. This guide will reference "
TrueCrypt."
-
General knowledge of how to reformat devices.
1.) First, you may either normally delete all the files contained on the device, or securely erase them if you have
such a tool at your disposal. Your preference here doesn't matter at this stage of the process. Be sure all hidden files, and other hard-to-find data, are deleted.
2.) Open Recuva. What we're going to do is configure Recuva to securely overwrite data, and then proceed to do this to the entire device. Under Options > Advance, you may specify the behavior of secure overwriting. 1 pass is fine at the moment. Under the Actions tab, be sure that "Deep Scan" is checked. Once you're satisfied with the configuration, select the device and scan it for deleted files. Check all files, right-click any one of them and select "Secure Overwrite Checked." Now that one overwriting pass has been made, it's time to encrypt the device...
Background info: When data is deleted, the system merely places a flag on that data letting the system know that it can be recycled for other files. Data is not, by any means, actually removed from the device. Some techniques can be applied to recover data that has been deleted. Secure overwriting allows you to replace that data with random garbage so that it cannot be recovered. There is still some concern as to how effective this measure is by itself.
This holds true for other types of devices, as well: FlashDrives, memory cards, et al. All recycle data the same way.
3.) Open TrueCrypt. What we're going to do is encrypt the device. I will give a bit of basic info about what this process is, and why it's beneficial, in the paragraph following these instructions. Click Volume > Create New Volume. If the device you want to encrypt is not a system drive, (i.e., it is not the very HD you are using at this very moment) then select "Encrypt a non-system partition / drive." Next > Standard TrueCrypt volume, and select the device from the drop-down list. (or click the "Select Device..." button) Select the entire device, as opposed to a specific partition that might be on the device. Specify any encryption parameters you wish. It generally does not matter for the sake of this exercise. (though, a cascading encryption is recommended) Be sure to specifiy a ridiculous password, having many characters of mixed letters, casings, numbers and punctuation. This is not a password you need to remember, because you will not be decrypting the device. Now, encrypt the device.
Background info: Encryption is a process in which data is converted into what appears to be garbage. This "garbage" can only be understood through the use of a specified password, or key, that instructs the system as to how to translate the data. Without this password, the data can only be seen as garbage. As an analogy, let's imagine that you decided to invent your own language. Every word in this language indeed has a meaning, but because you invented new ways to represent these meanings, only you can understand it. If you began to spout all of your thoughts to other people using this invented language, none of them would be able to understand you. In a way, your HD is speaking its own language. Without knowledge of how this language is decoded, it's just utter nonsense.
4.) Now that we've encrypted the device, it's time to reformat it. To scramble any possible remnant of data on the device, you may feel free to reformat, encrypt again using a new password, reformat, encrypt again, rinse and repeat. If you scan the device for deleted files, it will appear that no files have ever been placed on the device to begin with.
Warnings: Encrypting a device, and then reformatting it without decrypting it, can potentially cause permanent damage. Some hardware / software may see the device and think that it has never been initialized, and thus make an attempt to initialize it. I can't be held responsible for any such damage incurred by the use of this guide. (although, you can take assurance in the fact that I have applied this method to some of my own devices without any damage)
Why is this effective? Not only have you securely overwritten your data to begin with, but you also converted it - and the entire volume - into an encrypted mass of tangled garbage. Regardless of how stringently forensic techniques are applied to your device, it would be like trying to interrogate an aphasic mime for all his secrets. The poor bastard couldn't put together a coherent sentence if he wanted to.
