Saturday, September 7, 2013

Plausible deniability of a hidden OS - Part 3

This is Part 3 of a 4 part post on using TrueCrypt to create a hidden operating system.

Links to each section:
Part 1 - (Un)boring intro with all the snazzy info
Part 2 - Setup your second partition
Part 3 - Setup your first partition (sounds backwards, I know) -- you are here
Part 4 - Other cool stuff -- COMING SOON

Part 3 - Setup your first partition

~So now that you have copied your operating system from Partition 1 to the inner volume of Partition 2 we need to securely wipe the contents of Partition 1. Otherwise, even if you reinstall Windows on Partition 1, someone with forensic capabilities may be able to recover the previous Windows installation Partition 1 and thereby build a case that you have a hidden operating system, etc.

~Using the default Department of Defense standard of 3 passes of random ones and zeros for wiping is quite adequate in my opinion. For utter paranoia, try additional passes -- though that could put your wipe time at days or weeks!...

~Click Wipe:

~Click OK here:

~More mouse fun! The more you move your mouse, the more securely and randomly Partition 1 will be wiped!

~Wiping in some cases can take all day/night, even at 3 passes. Other factors of course include the size and speed of your drive.

 ~Here is the success dialog:

 ~Click Exit:

~So now it is time to go ahead and install a fresh copy of Windows on Partition 1 as a decoy operating system. Just pop a Windows disc in there and install on Partition 1. (Don't accidentally install onto or delete Partition 2!!) Once that's done, download TrueCrypt onto the fresh decoy install and choose Create Volume. Then choose Normal since this will be the decoy installation and press Next:

~Choose Encrypt the Windows system partition...

~Choose Single-boot

~Make sure you select the same encryption algorithm here that you did when you created the inner volume on Partition 2. They must be the same because both the decoy and hidden operating systems use the same bootloader and there is a different bootloader for each algorithm.

 ~More mouse fun! Great to feel like you are a part of the process, huh? :-) Move that mouse for the greater good of your encryption strength!

~Click Next...

~Somewhere in there it asks you for the password. Can't remember at which point. (Oopsie.) Anyway, when it does, you need to enter Password A for the decoy operating system. Do you need any more sermons about secure passphrases and whatnot? Didn't think so. ;)

~It will also ask you about creating a rescue disc. Creating a rescue disc is pretty important, as you can see below. It might sound scary to have it laying around, but your system will still require the password even when using the rescue disc. It's not really a vulnerability any more than the presence of the bootloader itself which is put on your hard drive. Just make sure you put it in a safe place so you don't lose it.

~TrueCrypt creates an ISO and then helps you burn it to optical media as a rescue disc:

~The rescue disc is verified to make sure it was a good burn:

 ~Now we are going to tell TrueCrypt how we want the data wiped from Partition 1. Wiped again, you say? Yup. The last time we wiped Partition 1 was to wipe operating system from it that was copied to the inner volume of Partition 2. This time TrueCrypt is going to encrypt the decoy operating system and wipe the unencrypted version of it. If it didn't, then someone could potentially do forensics on Partition 1 and recover the unencrypted version of the decoy operating system. This would be especially bad for those who use their decoy system for activities which are of a lower level of sensitivity but sensitive, nevertheless. As stated earlier, the default of 3 passes should be quite adequate.

~As stated, this will take a while once it actually starts which will happen later...

~TrueCrypt is going to test everything before doing the final encryption and wipe. Click Test:

 ~TrueCrypt informs you that this is not the real thing and that actual encryption will not take place. However, if the test fails, then Window may fail to start. If this does occur, you can come back here and read the various options for repair. Hopefully, you will be good though.

~I scrolled down and took another photo:

~Time to test, then. Click Yes and then when your computer reboots it will prompt you for Password A. If you have any trouble, see the 2 previous images.

~After you've rebooted and typed Password A, hopefully this is what you are now looking at. TrueCrypt warns here that in the event of power loss or a system crash during the encryption process, data on the decoy operating system may be gone forever. I didn't mention backups sooner because I am assuming that you followed my advice in Part 2 and used a clean system with a fresh Windows install. So hopefully, you don't even need backups. If you do, read the instructions here on how to defer, backup data and then resume. If you don't need to make backups, then click Encrypt.

~The next 3 photos provide instructions on how to troubleshoot any potential future booting issues with the rescue disc... Press OK.

~TrueCrypt is now encrypting your decoy operating system on Partition 1! Folks, this is even more amazing than it may seem. It's actually quite remarkable. Think about it. What's happening here is that while booted into Windows (not a live environment!) TrueCrypt is encrypting the currently booted Windows AND wiping the non-encrypted version of it all on the fly without even rebooting. WHAT? How is that even possible? It's more magic from the TrueCrypt people!! If this doesn't make you feel like donating, what will???!!!

~If you want, you can setup additional non-system encrypted volumes to be mounted at boot up, but that is outside the scope of this article. 

~You can click Do not show this again here:

~But if you had clicked Show more information you would have seen this, which was shown earlier -- so not that big of a deal.

~Alright, let's test this baby! If you reboot, you should get the bootloader shown below. If you type Password A, you get the decoy operating system on Partition 1. If you type Password B, you will get the hidden operating system on the inner volume of Partition 2! Don't worry, if you press Escape it doesn't really bypass authentication as long as you have encrypted the drive (which you just did.) It would only work if you had a TrueCrypt bootloader sitting on top of an unencrypted system, which is not the case here.

~If instead of typing the password or Escape you press F8, you will get some options which you will hopefully never need. Most of these options are only there because this same bootloader gets copied to the rescue disc and would be run from there.

~Awesome! So you've set up your system! In Part 4 I will boot into a live CD just to prove out whether or not I can see the encrypted data and show you some cool stuff, so stay tuned!

Links to each section:
Part 1 - (Un)boring intro with all the snazzy info
Part 2 - Setup your second partition
Part 3 - Setup your first partition (sounds backwards, I know) -- you are here
Part 4 - Other cool stuff -- COMING SOON

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