https://en.wikichip.org/wiki/x86/sme#Overview https://www.qubes-os.org/doc/anti-evil-maid/
There are so many possible evil maid attacks that I think it would be useful to add a pysical layer, just in case.
It would be interesting to leverage SEM to run a version of qubes where not only are the VMs isolated by the Xen hypervisor but are also separately encrypted using the PSP.
If memory serves correctly they achieved the best results by using a can of compressed air to freeze the ram in place before removal.
//Small edit to wording
It's a matter of being more determined than your attacker. Imagine a device that will irretrievably brick itself if tilted more than a certain angle, if left unpowered for more than a certain time, etc. and that has to be under constant guard. This seems almost incompatible with any kind of personal use. And some measures may only work in one instance, with the attacker planning for them the second time they have an operation.
Many attackers also don't have the same restrictions the police has. In the Ulbricht case the police may have been forced to use a device that copies the data with no human intervention just to preserve the chain of evidence and not have suspicions that the agent operating the laptop altered it while installing additional software. An attacker operating in the grey/dark area might just immobilize the user, snip the wrist cable, and then retrieve the necessary data either directly at the console or by siphoning it via the network. Or the police may just start video recording in great detail every step from the moment an agent touched the laptop until the data was exfiltrated to remove suspicions of tampering.
But such a tool would be of great effect against an undetermined, unsophisticated attacker committing a crime of opportunity.
Putting a regular device in a safe leaves it exposed to someone unlocking the safe and compromising the device by implanting a keylogger inside or even by putting a replacement identical device there and waiting for the user to type the boot password.
As for methods of emergency clearing sensitive data from memory while in operation, whatever method is employed will work once. The next time the attacker is ready for that particular method. For example the police might just have to completely immobilize the suspect (and their hands) and keep the laptop in the vicinity while the "dead man's switch" is bypassed.
Not exactly. You don't want someone sneaking in and misappropriating the HSM to authorize something bad. And if you set the system up for unattended recovery from a power failure, then in all likelihood someone walking off with the server the HSM is in can use those keys indefinitely. But there are options.
Some HSMs have self-destruct mechanisms that attempt to prevent physical access to the private key (ie by lapping the chip). Some vendors (nCipher, IIRC) have a smart card (a second HSM) that is required to authorize certain activities, like signing, or key recovery. In fact they had a byzantine generals solution that either had the key or a password for the key split between n cards. In the latter case you needed one of the original HSMs in order to clone the key, so a movie plot where you kidnap the entire team at a conference doesn't work. During initial setup the cert would be generated on the first HSM and copied to the others, having never seen daylight.
That system was quite difficult to explain to users, and I had to document it just so I wouldn't get confused and trigger a reset of the evaluation hardware (at which point all of our test artifacts have to be rebuilt).
It might be more complicated to start WWIII than to protect a signing certificate, but only just.
I think we're talking about exactly the same thing :). That's what I meant by "even they rely on being stored in a physically secure room and protected from theft". Despite all the hardening that is applied to the device, it must always be kept secure and supervised. As an example, this is what Safenet considers the intended installation environment should be [0].
This can't be effectively applied to a personal computer.
[0] http://cloudhsm-safenet-docs-5.3.s3-website-us-east-1.amazon...
Then your biggest problem is people thinking that stealing the cards will get them anything. Which, they're not entirely wrong, because those things are damned expensive. So you need a 'kinda' secure facility.
Again, the issue is that any hardware that will start up for you without any action on your part will likely start up for anybody else, too. Your laziness will probably win out...
"In recent years, however, it has become increasingly challenging to execute cold boot attacks or perform physical memory forensics due to the introduction of DRAM memory scramblers. Modern processors with DDR3 and DDR4 DRAM scramble data by XOR’ing it with a pseudorandom number before writing it to DRAM [5], [6]. These scramblers were initially introduced to mitigate the effects excessive current fluctuations on bus lines by ensuring bits on the memory bus transition nearly 50% of the time"
DDR4 is also yes in the lab -
https://web.eecs.umich.edu/~misiker/resources/HPCA17-coldboo...
I’m not sure if it’s something they offer on current models, or to individuals at all (I bought it used from a corporate IT asset liquidator so it was likely originally purchased as part of a bulk deal). Regardless it makes a great little Linux box!
Also, does it still work if you open the machine with the power disconnected and battery removed?
... I don’t know of anyone actually implementing this though :)
If the latter, the server would probably be okay, and it would take a very long time for the termites to damage the surrounding room enough to be a security deterrent.
Nobody I know who got arrested ever managed to destroy anything. When I think about it, we all assumed the cops would storm in when we were in the act of doing something bad, probably like in the movies lol, when in practice, they tend to pick you up when you are really off guard, duh.
Very few people had automatic protections because like, our parents would probably get mad if we burned down the house :)
When it came to me, the FBI did knock on my front door, and I managed to dd if=/dev/random of=/dev/hda
I lost my entire BBS, all the custom code and ANSI I had for it, among other ancient treasures that I'd probably still have with my napster mp3s :)
Of course they didn't come for me, there had been a flasher in the neighborhood on halloween...
When I was a teen, I somehow got a modem number at NASA, and I stupidly gave it to a friend. He tried to brute force it, but he got door knocked. He quickly formatted his disks, but it wasn’t even the cops haha!
After 18, you're done, even if they can't think of a good charge, they'll make them up, which is exactly what they did back then, cross state commerce was a blanket thing to grab folks.
I stopped doing anything questionable well before I turned 18.
Today, you should encrypt everything, and cut power before physical access is obtained. Will that count as "tampering"? I was just turning off my computer. No, I do not remember the key.
In practice, the only real protection we had (those of us in my social group) was that we were minors, and lucky that laws hadn't caught up yet.
If I delete a file on my computer today that would be potentially "evidence" if seized, and the police come knocking tomorrow, I haven't committed a crime by using my personal computer in the past.
I only saw people in suits with a black car outside knocking on the door, also this was like 30 years ago so don't twist my arm :)
Could you expound on what this means? In the USA/UK, people most "at risk" of police kicking down the door seizing their laptops/computers while they are still running are child pornographers.
Perhaps this can be used "for good" under oppressive regimes (i.e. if you are a dissenting journalist) but then I think you won't get a fair trial anyway and having a kill switch just means more prison.
It can happen if you are a political activist in any fashion. Nothing violent, just speaking out for rent control and against gentrification can get you in trouble. Or hanging around with the wrong people.
When it happens, you want to leave them as little rope as possible to hang you with. As I said, the courts still are honest and they won't make up evidence, but they will take everything they can find to make a case - and to learn about your structures and networks while they are at it.
You are right, that in real oppressive regimes all bets are off. If they want to get you, they won't stop at their own laws. But even then, these techniques are useful against industrial espionage. If you are doing business in certain countries, the "evil maid" is quite real...
As for the dissenters, I’m sure they would appreciate their co-conspirators remain secret.
Can you provide any evidence at all of police or "thugs" (or anyone, really) kicking down doors to get at trade secrets being a common problem? Because there are countless news articles of police raids seizing computers to stop child porn[0].
I speculate any tool billed as "anti-forensic" will be used for immoral purposes more commonly than moral purposes.
[0] https://en.wikipedia.org/wiki/Jared_Fogle#Child_pornography_...
That does not mean it should be banned. Knives are used for many things from cutting food and opening boxes to killing people. Nitrate based fertilizers can be used for vastly improving crop yields but can also be used for bombs. Encryption can be used to protect your sensitive personal data from criminals and prying eyes, but can also be used by the criminals themselves to hide their activities.
No state (even if it was the most ethically illuminated utopia) has the power to protect every person in every place at every time. Banning defensive tools is asinine as rarely does it mean that a criminal won't use them against you.
It is doubly foolish to believe that the police are the only users of forensic software when there is credit card theft and multmillion dollar ransomware rings out there. Robbing a bank by force or by heist is foregone jail but snatching a laptop from a banker? Far more petty in risk and disguised as mere property theft as opposed to the data theft.
Somewhat related, I'm wondering about the physical security of computers. There is an attack where they open your PC, take out the ram, and freeze it immediately so the bits don't decay and they can extract your encryption keys.
All BIOSes have an option for cassis intrusion detection, but I've never seen a case that has the necessary cable. Has anybody here set up a chassis intrusion kill switch that erases the RAM/shuts down the PC etc. if the case is opened improperly? Can you buy anything like this on the market?