5 ms·

That's why TrueCrypt, and I think Vera Crypt have support for a volume that can be decripted with two keys - one will yield a decoy volume where its free space

That's why TrueCrypt, and I think Vera Crypt have support for a volume that can be decripted with two keys - one will yield a decoy volume where its free space is actually the real volume that you want to protect which gets decoded only with a second key I'm not sure if the entropy analysis of that free space can suggest that there's something funky about that free space or not.. Because usually free space is either actual info just marked as deleted, or info reset to zeros by some pro active wiping of the free space. So, having a bunch of whacky data that doesn't look like any kind of file, can probably be used as a tell tale sign? No?

brianjlogan 7y ago
In most instances I think torture would yield all of your knowledge including the secondary unlock. Unless you're thinking your attacker would exclude you from torture for "yielding" the password. I would think if they are capable of torturing you than they wouldn't stop at a polite confession.
- varenc 7y ago
  VeraCrypt hidden volumes are supposed to be a 100% deniable. There’s no way to prove they exist. The idea is that they’ll stop torturing you because they don’t know of the existence of the hidden volume. (In practice I suspect it leaves some subtle queues, but maybe perfect for a border crossing )
  - frandroid 7y ago
    My understanding is that people who torture you don't know what you don't know; so they don't know when to stop. As such, they'll keep torturing you way past the point where you've admitted to everything you know. This is why information obtained under torture is considered unreliable: eventually you'll just say anything to stop the torture; further admissions will support the use of torture as an information extraction tactic, and then lead to more torture.
    - elif 7y ago
      Yes but, under what pretext would you torture someone who has complied with all of your requests? ~"Do you have any encrypted data we can't see?" "Yes. The entire drive is encrypted" ~"What is the key?" "iloveapplesauce6969" ~"Well, that worked and I see your data here. What a lovely family.. is that Disney world?" "Yes it was Timmy's 5th birthday" ~"I'm going to waterboard you"
      - frandroid 7y ago
        Them: "You're still hiding something" You: "This was everything!" Them: "We don't believe you" -rubber hose- You: "Stop it! I planned to blow up the world trade center!" Them: "We knew you were a liar." To themselves: "Wow, torture works." Rinse, repeat.
- bootlooped 7y ago
  Border agents inspect and copy many more digital devices than just those of people they actively suspect of something, or are willing to torture.
- lukifer 7y ago
  In theory, you could just keep adding n+1 layers of fake passwords (maybe with realistic fake data), on the hope that after n attempts, they think they've broken you and hit the jackpot. But as sibling commenters describe, if sufficiently motivated, there's no reason that an authoritarian state wouldn't just keep torturing you anyway. :(
  - bb88 7y ago
    > if sufficiently motivated, there's no reason that an authoritarian state wouldn't just keep torturing you anyway. Sure, but it helps to make it look like you're someone not worth torturing in the first place. The same look would happen when you decrypt your TrueCrypt partition. Large unused sections on the laptop with random data is a bad look for someone trying to say they're not a spy. If it were me, I would do something more like bring a laptop with a bunch of biblical research and ask everyone in the checkpoint, if they've taken Jesus Christ into their heart. This of course assumes that in this instance the authoritarian regime just finds these sorts of religious people annoying and not dangerous. I wouldn't do this coming into Iran, say.
bArray 7y ago
An encrypted volume (fixed space) should even remove the white space. After all, knowing the size of a file contained within could leak information about its contents. I imagine the only way to detect a volume would be to have it decrypted (enforced by law enforcement), to take the supposed volume type and files within and then re-encrypt with the same data. If your volume and the supposed clone are different, it would suggest that you have hidden another volume within.
- abhorrence 7y ago
  I think the defense is that (assuming IVs, nonces, etc... are held constant) that the files would encrypt identically. And the excuse for the rest of the disk is “it gets filled with random bytes to obscure how much disk space is actually being used.
threatofrain 7y ago
It's also why, IMO, obscurity is a valid component to security.
- ivankolev 7y ago
  Yes, but defence in depth/layering is the over-arching, higher-order concept in the security game.
- OJFord 7y ago
  I agree, not least because I can't see how to define 'obscurity' without it also being a basic explanation of encryption. (Good) Encryption is a (secure) mechanism for obscuring data, surely?
  - antepodius 7y ago
    It seems like there's something like a way to measure the different mechanisms in terms of how inherently decoupled they are from their surroundings. So, a the fact you have to send messages to my server in a particular format is one type of obscurity- but it's highly non-incidental, linked to many different parts of the world (i.e. it's some common network protocol) and more easily investigated (you could get interesting different responses by vary what string of bits you send). In comparison, which particular password I use can be very highly decoupled from the rest of the world and my architecture, which makes it vastly more (reliably) obscure. Somewhere inbetween "you have to know my server exists to send 'login:admin password:pass' to it" and "the volume's encrypted with a 2048-bit cypher generated from atmospheric entropy" is, maybe, a useful middle ground. Hidden volumes seem like more of a defensive meta-obscurity, in that they obscure your metadata (your ownership of a particular piece of encrypted data).
  - XMPPwocky 7y ago
    https://en.wikipedia.org/wiki/Kerckhoffs%27s_principle https://en.wikipedia.org/wiki/Kerckhoffs%27s_principle
    - OJFord 7y ago
RcouF1uZ4gsC 7y ago
I think the authoritarian regime will just torture anyone with any VeraCrypt or TrueCrypt volume and the plausible deniability will come back to bite you as you can't prove that there are no other hidden volumes.
- rolltiide 7y ago
  The point of a decoy is to satisfy scrutiny. Truecrypt WITHOUT decoy will escalate the scrutiny, truecrypt WITH decoy will avoid further scrutiny.
  - XMPPwocky 7y ago
    The problem is the level of scrutiny. Against some attackers, decoys have very very nasty game-theoretic failure cases. Specifically- there's no limit to the number of decoys that could be on a disk. So you can get into the situation where you've decrypted every volume that exists, under coercion, but your adversary believes there are more volumes remaining. By design, you have no way to prove that there isn't more hidden data on that disk. This is unlikely to end very well for you.
    - sveme 7y ago
      If that‘s the operation mode of your foe, it‘s not going to end very well for you anyways.
      - bb88 7y ago
        It's more complex than that right? If you have a VeraCrypt partition that they can detect, it makes you look like a spy. Lots of random data in unused sectors on your hard drive is a bad look if you're trying to convince the border agent you're not a spy. If you have a plain old laptop with some mildly embarrassing information on it that's not encrypted, you might still be a spy, but they wouldn't be able to tell from the laptop itself.
    - deleted 7y ago
      [deleted]

brianjlogan 7y ago

In most instances I think torture would yield all of your knowledge including the secondary unlock. Unless you're thinking your attacker would exclude you from torture for "yielding" the password. I would think if they are capable of torturing you than they wouldn't stop at a polite confession.

varenc 7y ago
VeraCrypt hidden volumes are supposed to be a 100% deniable. There’s no way to prove they exist. The idea is that they’ll stop torturing you because they don’t know of the existence of the hidden volume. (In practice I suspect it leaves some subtle queues, but maybe perfect for a border crossing )
- frandroid 7y ago
  My understanding is that people who torture you don't know what you don't know; so they don't know when to stop. As such, they'll keep torturing you way past the point where you've admitted to everything you know. This is why information obtained under torture is considered unreliable: eventually you'll just say anything to stop the torture; further admissions will support the use of torture as an information extraction tactic, and then lead to more torture.
  - elif 7y ago
    Yes but, under what pretext would you torture someone who has complied with all of your requests? ~"Do you have any encrypted data we can't see?" "Yes. The entire drive is encrypted" ~"What is the key?" "iloveapplesauce6969" ~"Well, that worked and I see your data here. What a lovely family.. is that Disney world?" "Yes it was Timmy's 5th birthday" ~"I'm going to waterboard you"
    - frandroid 7y ago
      Them: "You're still hiding something" You: "This was everything!" Them: "We don't believe you" -rubber hose- You: "Stop it! I planned to blow up the world trade center!" Them: "We knew you were a liar." To themselves: "Wow, torture works." Rinse, repeat.
bootlooped 7y ago
Border agents inspect and copy many more digital devices than just those of people they actively suspect of something, or are willing to torture.
lukifer 7y ago
In theory, you could just keep adding n+1 layers of fake passwords (maybe with realistic fake data), on the hope that after n attempts, they think they've broken you and hit the jackpot. But as sibling commenters describe, if sufficiently motivated, there's no reason that an authoritarian state wouldn't just keep torturing you anyway. :(
- bb88 7y ago
  > if sufficiently motivated, there's no reason that an authoritarian state wouldn't just keep torturing you anyway. Sure, but it helps to make it look like you're someone not worth torturing in the first place. The same look would happen when you decrypt your TrueCrypt partition. Large unused sections on the laptop with random data is a bad look for someone trying to say they're not a spy. If it were me, I would do something more like bring a laptop with a bunch of biblical research and ask everyone in the checkpoint, if they've taken Jesus Christ into their heart. This of course assumes that in this instance the authoritarian regime just finds these sorts of religious people annoying and not dangerous. I wouldn't do this coming into Iran, say.

bArray 7y ago

An encrypted volume (fixed space) should even remove the white space. After all, knowing the size of a file contained within could leak information about its contents. I imagine the only way to detect a volume would be to have it decrypted (enforced by law enforcement), to take the supposed volume type and files within and then re-encrypt with the same data. If your volume and the supposed clone are different, it would suggest that you have hidden another volume within.

abhorrence 7y ago
I think the defense is that (assuming IVs, nonces, etc... are held constant) that the files would encrypt identically. And the excuse for the rest of the disk is “it gets filled with random bytes to obscure how much disk space is actually being used.

threatofrain 7y ago

It's also why, IMO, obscurity is a valid component to security.

ivankolev 7y ago
Yes, but defence in depth/layering is the over-arching, higher-order concept in the security game.
OJFord 7y ago
I agree, not least because I can't see how to define 'obscurity' without it also being a basic explanation of encryption. (Good) Encryption is a (secure) mechanism for obscuring data, surely?
- antepodius 7y ago
  It seems like there's something like a way to measure the different mechanisms in terms of how inherently decoupled they are from their surroundings. So, a the fact you have to send messages to my server in a particular format is one type of obscurity- but it's highly non-incidental, linked to many different parts of the world (i.e. it's some common network protocol) and more easily investigated (you could get interesting different responses by vary what string of bits you send). In comparison, which particular password I use can be very highly decoupled from the rest of the world and my architecture, which makes it vastly more (reliably) obscure. Somewhere inbetween "you have to know my server exists to send 'login:admin password:pass' to it" and "the volume's encrypted with a 2048-bit cypher generated from atmospheric entropy" is, maybe, a useful middle ground. Hidden volumes seem like more of a defensive meta-obscurity, in that they obscure your metadata (your ownership of a particular piece of encrypted data).
- XMPPwocky 7y ago
  https://en.wikipedia.org/wiki/Kerckhoffs%27s_principle https://en.wikipedia.org/wiki/Kerckhoffs%27s_principle
  - OJFord 7y ago

RcouF1uZ4gsC 7y ago

I think the authoritarian regime will just torture anyone with any VeraCrypt or TrueCrypt volume and the plausible deniability will come back to bite you as you can't prove that there are no other hidden volumes.

rolltiide 7y ago
The point of a decoy is to satisfy scrutiny. Truecrypt WITHOUT decoy will escalate the scrutiny, truecrypt WITH decoy will avoid further scrutiny.
- XMPPwocky 7y ago
  The problem is the level of scrutiny. Against some attackers, decoys have very very nasty game-theoretic failure cases. Specifically- there's no limit to the number of decoys that could be on a disk. So you can get into the situation where you've decrypted every volume that exists, under coercion, but your adversary believes there are more volumes remaining. By design, you have no way to prove that there isn't more hidden data on that disk. This is unlikely to end very well for you.
  - sveme 7y ago
    If that‘s the operation mode of your foe, it‘s not going to end very well for you anyways.
    - bb88 7y ago
      It's more complex than that right? If you have a VeraCrypt partition that they can detect, it makes you look like a spy. Lots of random data in unused sectors on your hard drive is a bad look if you're trying to convince the border agent you're not a spy. If you have a plain old laptop with some mildly embarrassing information on it that's not encrypted, you might still be a spy, but they wouldn't be able to tell from the laptop itself.
  - deleted 7y ago
    [deleted]