Comment by Grimblewald
19 hours ago
VeraCrypt has a cool function which is a reserved space for a decoy OS.[1] Everything else registers as free space while decrypting to dummy volume. You make the dummy volume look lived in, and forget. provide dummy password, volume decrypts such that only dummy is accessible/readable. give proper password, real OS and FS decrypt and load.
Something like this may need to become the standars over duress pins which should be treated as a fallback or more extreme alternative. Right now, A single choice to reasonably and rightfully protect your privacy reuslts in jail time over something which likely wouldnt have resulted in any issues if superficial compliance was observed.
These goons, even if a branch of a facist regime, are ultimately burocrats with violent options to settle. They aren't doing forensics on your device etc. They have neither means nor knowledge to do so. They just need to tick their boxes. Did the phone unlock? tick. Did our spyware complain? no? tick. Overall appearance of compliance from person? yes? tick. free to go, next!
You just have to find ways to stay safe without agitating their workflow and all is well.
- [1] https://veracrypt.io/en/VeraCrypt%20Hidden%20Operating%20Sys...
I worry about approaches like this because maybe the forensics tool fills all available space and then clears it, noticing that this particular phone is an anomaly re:
If you're hiding something in "empty space" it won't behave like empty space when you try to fill it.
I think we need to be stenographically smarter. Like if there's some mechanism of deduplicating blocks across volumes, then perhaps when given the special key you could temporarily render a volume whose parts are hidden in the data already occupied by the other volume and then just run it in memory so that a reboot clears it.
this will likely fail as block devices aren't dumb anymore, the firmware state will out the hidden volume. counting on the laziness/unsophistication of an adversary isn't a great move.
this problem may be solvable by a purpose-built abstraction where every write no matter what address will look identical to the firmware (naively, a randomized key-value map).
I largly agree, hence why the prudent move is not visiting shitholes like the (current) USA with anything important on your person.
However, if you must do it, there are better options than duress pins that wipe a device.
Not that shufflecake solves the issue you highlighted, but I found the shufflecake FAQ to be a good intro to the topic for anyone curious. It does a good job explaining the threat vectors and the relevant trade offs, in particular the TRIM and ORAM sections. It’s also just a cool project: https://shufflecake.net/
What does “block devices aren’t dumb anymore” mean?
Modern SSDs are log-structured under the hood. The presentation to the host system as a random access block device is an abstraction on top of that, emulating the semantics of spinning rust. Inspecting the underlying log will reveal the location of the hidden area, even if it looks random when read linearly.
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SSD/NVMe keep track of what regions are wiped and which contain data that has to be preserved. To hide something in the seemingly-unused space, you have to turn off trim, eat the performance cost, and pretend you had a reason to have turned off trim.
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I agree that trying to outcompete seems really hard, but also:
Given what the experience of using a non-rooted phone is like, how very very tight the sandboxing is and how useless it is a General Purpose Computer that will tell you anything: I find it very hard to believe the unlocked phone is going to let you start probing firmware & snooping on hidden volumes.
This post sent my BS detector on high alert. I'm struggling to take it seriously.
you do realize what the threat model behind a hidden volume is right?
no one will be accessing the firmware through the OS, they will access it from the PCB/chip/debug port. there is no point to a hidden volume if you cannot credibly deny its existance.
Even in places where you can’t be compelled to hand over a password, attempting to deceive the cops will get you thrown in prison just as reliably as destroying evidence.
Meanwhile cops can and do regularly deceive and lie to citizen and not only don't face any consequences but actively benefit from it.
I don't really see a problem with this assuming the deception is used to uncover crimes.
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The best thing to do in such a case is issue the following statement -
"I am in full physical compliance and will not interfere with investigation in any way, but I plead the 5th on answering any questions, and plead the 4th on any personal property", and just sit there silently. Let them break into the phone if they want.
true, but in that scenario you're going to prison either way. If you legitimately use the dummy for daily driving and hidden for sensitive work, then it's better than nothing.
Obviously a good alternative is a dummy device but it carries similar risks, and the best option is to simply not go to authoritarian shitholes like the USA. Thankfully I've been able to avoid/push for US folks visiting us instead, but honestly the alternatives are as bad.
Its a shit situation where most reasonable actions carry real risks, its up to individuals to choose what is acceptable risk to them, but a dummy os you use as a daily driver for inconsequential work is, to me, an ideal midground.
No, you're being very dramatic. Lying to cops is very often your best strategy.
I doubt this person will be found guilty. They will be able to prove he wiped his phone, but it will be hard to prove he destroyed evidence.
It's not possible afaict on phones because they use flash memory.
https://veracrypt.io/en/Wear-Leveling.html
https://veracrypt.io/en/Trim%20Operation.html
>VeraCrypt has a cool function which is a reserved space for a decoy OS.[1] Everything else registers as free space while decrypting to dummy volume. You make the dummy volume look lived in, and forget. provide dummy password, volume decrypts such that only dummy is accessible/readable. give proper password, real OS and FS decrypt and load.
See: https://news.ycombinator.com/item?id=49057812
Implementing it in a convincing way is harder than you think. Moreover if you're under the type of regime that will throw you in jail for not giving up a password, they're probably not going to let you off the hook because they can't definitively prove you have a hidden volume.
I could be wrong, but my understanding is that the dummy OS views the remaining space as legitimate and accessible free space. Using dummy directly is of course dangerous, as you might overwrite sectors with legitimate data, but also, you can access dummy os from secret. so you'd drive dummy from secret to prevent that but can load dummy as main if under duress and it looks fine. Browser, logged into various inconsequential things, random files for inoffensive memes and other human stuff in downloads folder etc. maybe an email account you've signed up to a few newsletters and e-stores that send spam logging in via an email client that auto-launches etc.
Done well, I see no reason it should raise redflags in routine stops, so unless you're being targeted (at which point you've got way bigger problems) it should just seem like you're a run of the mill person who does not use their device to its full capacity, which is the majority of users.
at some point, having any mitigations even present is a problem. At some point being met with a boot password at all is a problem that puts you on a list. I have no solution there other than to not go to those countries or keep dummy hot.
If you read the linked thread, you'd see the reasons are:
1. SSDs (including phones) have TRIM/discard, so you need to disable it, otherwise the hidden volume would get wiped. You going out of your way to disable it is going to be suspicious.
2. Even if the above wasn't an issue, you can't really use the outer os to any meaningful extent, because you run the risk of overwriting the inner volume. That makes your decoy os suspicious. It's not definitive proof you have a hidden volume, but I doubt the authorities would care too much about that.
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This seems like the kind of thing that would put US citizens in way more legal jeopardy than just using a secure phone with a long password, refusing to unlock it, and buying a new one if the officers involved confiscate it out of spite.
This is always been the dumbest thing about "hidden volumes": It relies upon your adversary not knowing about veracrypt's hidden volume. Which BTW, is plainly ADVERTISED on the web site. The second he knows you have veracode, he will ask for the other encrypted volume.
See also relevant XKCD:
https://xkcd.com/538/
But Veracrypt can be used for encryption of a volume, without creating a hidden volume. I assume it would often be used this way.
The $5 wrench decryption technique would be even more unpleasant if you hadn’t created a hidden volume, as there would be no way to prove you hadn’t.
Should people be sure to never use Veracrypt volume encryption unless they create a hidden volume? I have trouble even thinking this way!
The $5 wrench isn't about breaking encryption. It's about breaking will power. If they achieve their goals great for them. If not they proved the second volume either didn't actually exist or your will power was stronger than the $5 wrench. Either way they're probably way more happy with the outcome than you would be.
As long as the border your crossing doesn't respect the 4th Amendment, the best approach is to not carry anything incriminating across it, nor anything that may make you suspicious.