The point is to at least make them resort to hitting you with the $5 wrench, at which point they're probably committing a more serious offence than what you're up for (dependent on country).
Doesn't have to be a literal wrench right? A government can trivially and legally make you miss the itinerary that made your holiday possible that you've saved up for the rest of the year with no restitution that I'm aware of in any jurisdiction. They can confiscate 'evidence' (any computer and (backup) storage media in your house) for years. They can do a heck of a lot that's more annoying than medium amounts of wrench swinging
And as for street thugs, sure it won't be a wrench, more likely they'll flash a knife and unkindly suggest you remove the lock screen
Taken as a metaphor rather than a literal wrench, you don't think it's accurate?
> A government can trivially and legally make you miss the itinerary that made your holiday possible that you've saved up for the rest of the year with no restitution that I'm aware of in any jurisdiction. They can confiscate 'evidence' (any computer and (backup) storage media in your house) for years.
This could be preferable to handing over private data about contacts, communications, sources, client information, etc. Especially if it has life-changing implications for yourself or other people!
The wrench attack is still far weaker than a push-button attack.
In the wrench attack you are aware that you have been attacked, and you're aware of what data the attacker gains.
Additionally there are schemes like deniable encryption which can mitigate the outcomes of such an attack or serve as a red herring.
Furthermore it's dependent on physical intimidation which is expensive to scale and can be met with your own physical intimidation. In order for a wrench attack to scale to an entire society you have to send the gestapo to everyone's house whereas push-button attacks scale by default unbenownst to the victims and enable more nefarious systems to be built on top of them. In the USA this would mean interrogating some well armed citizens.
Lastly, you aren't forced to give up the key by any means. They can torture you to death and there is nothing they can do if you don't want to give up the key. There are some secrets in the game of love and war that are worth taking to - it's why spies are equipped with cyanide pills.
The point of the comic is pretty obviously to make fun of the expectations of cryptography geeks; you know, the sort of people who use 4096 bit RSA keys for the coolness factor. It is a stretch to imply it is suggesting that encryption is somehow futile.
The United States has famously shot and killed protesters in the Vietnam war era. They have dedicated torture facilities for people suspected, not even convicted, of terrorism. Police officers use lethal violence for no reason every month and rarely get more than a talking to.
In a perfect society, your point makes sense, but I don't see why the authorities in the real world would need to care about committing a worse crime.
If you're that much of a coward, you won't get hit by a wrench anyways because you will give your keys up immediately. But you will force your enemy to exert additional effort.
It works for the same reason locks on houses work against cops or criminals, despite the existence of lockpicking and locksmiths. There are various layers of physical security, and while no layer can prevent an attack absolutely they each increase the cost of an attack.
The system is only as secure as it's weakest layer.
So in a mixed information/physical system like a smartphone why should we allow the weak point to be the information system? To improve the information system we need only to rewrite the software, so the per-unit cost is nothing in the large.
The offenses of a regime at its apex would've led to it being stopped had they started out that way, but they didn't.
What you've hit on is the basic problem of treating privacy as a means to an end though: no level of it protects you from fascism, but it is a means by which fascism can be opposed - in many cases at personal cost to yourself.
In theory I have no secrets, and the contents of my phone or life if public would be of no consequence to me. In practice, when the regime starts flustering itself that I have no secrets for them to reveal the hopefully people will oppose it - or I get a decent warning that it's time to bail.
Everyone thinks they're brave until they get punched in the face. The fact that a handful of terrorist attacks decades ago were all it took to push society into voting for control freaks who built a worldwide surveillance state to nanny them tells me all I need to know about how brave people really are.
According to The Guardian, the US Department of Justice is prosecuting Atlanta resident Samuel Tunick after he allegedly gave a GrapheneOS duress PIN while border agents were trying to search his Google Pixel phone.
It sounds like he did give them the password, but it was the password to wiping his phone and not unlocking it. I'm surprised they didn't back up the device first.
From what I understand he was not formally arrested at the time, just interrogated at the border. I am not familiar with US laws but from what I understand the device was not (yet?) considered evidence in an investigation. I imagine backing up might not be as easy an option without tearing down the device as the memory chip is no the device mainboard, so not something you can necessarily do on the side of the road or at a border without a formal warrant/investigation.
This is really an interesting case. Hope to see a ruling here. The edge cases are really interesting as well, like the fake pin on the back of the phone. I also wonder generally about the 'destruction' of data
Wouldn't the government need to prove that there is no backup, because just making it more difficult (like hiding) would probably not call for the paragraph. Unfortunately for the rest of us the defence is based on more proven grounds. I guess only plausible deniability is helpful: I e.g. would love to see my trusted android space being empty/recreated on false password.
> The edge cases are really interesting as well, like the fake pin on the back of the phone.
"Your honor, I have the real pin memorized because I use it all the time, but since I can never use the duress code, I had to keep it somewhere handy."
Or
"Pickpocketing and phone-snatching is a real problem overseas, I put it there so that criminal would wipe the phone trying to get in, denying them access to things like my bank account."
Heck, those aren't just plausible, they might be a good idea.
> I'm surprised they didn't back up the device first.
There's no use in taking an image of the SSD and restoring it after a wipe. Data needed to derive the key encryption keys was wiped from the secure element. Separately from that, there's also additional data on the SSD needed to derive the key encryption keys which the TEE hardware will no longer consider valid.
Entering the duress PIN/password does the following:
* wipes TEE hardware keystore
* wipes secure element hardware keystore
* wipes the secure element other than Factory Reset Protection data which isn't used by GrapheneOS at this time
* wipes the encryption metadata on the SSD with special wiping commands
The secure element data is inside the secure element's internal storage. TEE keystore keys are normally stored encrypted on the SSD with a hardware-based anti-rollback storage system to prevent reusing deleted keys. The secure element keystore is a lot more secure.
The most important data that's wiped is the Weaver table on the secure element. Weaver is the secure element rate limiting feature we describe in our post. It's implemented by the OS passing a dedicated hash of the initial key derived from the user's PIN/password. If it's the valid hash, the secure element provides a token needed alongside the initial derived key for the final key derivation. If it's not valid, it's a failed attempt wasting one of 20 attempts and triggering a hardware enforced delay.
It also isn't possible to simply image the SSD and then try to brute force the PIN/password due to the secure element rate limiting and the final key derivation done in the TEE.
It isn't the same as a typical disk encryption approach on a desktop, although GrapheneOS supports using a strong passphrase to avoid depending on the secure element rate limiting. GrapheneOS makes it convenient to use one via 2-factor fingerprint+PIN secondary unlock in After First Unlock state. It's the same as regular fingerprint unlock but with a PIN needed to complete it where incorrect ones count towards the limit of 5 attempts (reduced from 20 by GrapheneOS).
The alleged charges seem nonsense - destruction of property to prevent seizure? First no property was destroyed, and second they could still seize it. But US courts are a coin toss so it may still work for the government.
It sounds like he did give them the password, but it was the password to wiping his phone and not unlocking it. I'm surprised they didn't back up the device first.
The duress password does not wipe the phone. It wipes the encryption keys from the secure element. The phone's storage is the backup, but it is worthless, unless law enforcement has an attack against AES that does not require a brute force attack (unlikely).
This site is called Hacker News :), people might just want to learn how it works technically, so I think it is worth mentioning technical differences.
Also, it does make a small difference in practice. Erasing keys is pretty much immediate, while erasing storage can take some time (especially for phones with larger storage), so the attacker could still try to power down the device in some way to avoid all storage gets wiped.
I'm not sure it would have been that easy for them to back it up.
Depending on his settings.
You can disable the usb port entirely if you like, so that it is only possible to charge the device by switching it off. Or enable charging only when unlocked etc.
Or if his device had rebooted I don't think it would be possible to extract anything.
Yes, it would be interesting if the question was formulated like "we're gonna need a password" and this ends up being a lawyerdog situation. https://blogs.illinois.edu/view/25/574827
I hate this meme.
The point is to at least make them resort to hitting you with the $5 wrench, at which point they're probably committing a more serious offence than what you're up for (dependent on country).
Doesn't have to be a literal wrench right? A government can trivially and legally make you miss the itinerary that made your holiday possible that you've saved up for the rest of the year with no restitution that I'm aware of in any jurisdiction. They can confiscate 'evidence' (any computer and (backup) storage media in your house) for years. They can do a heck of a lot that's more annoying than medium amounts of wrench swinging
And as for street thugs, sure it won't be a wrench, more likely they'll flash a knife and unkindly suggest you remove the lock screen
Taken as a metaphor rather than a literal wrench, you don't think it's accurate?
> A government can trivially and legally make you miss the itinerary that made your holiday possible that you've saved up for the rest of the year with no restitution that I'm aware of in any jurisdiction. They can confiscate 'evidence' (any computer and (backup) storage media in your house) for years.
This could be preferable to handing over private data about contacts, communications, sources, client information, etc. Especially if it has life-changing implications for yourself or other people!
The wrench attack is still far weaker than a push-button attack.
In the wrench attack you are aware that you have been attacked, and you're aware of what data the attacker gains.
Additionally there are schemes like deniable encryption which can mitigate the outcomes of such an attack or serve as a red herring.
Furthermore it's dependent on physical intimidation which is expensive to scale and can be met with your own physical intimidation. In order for a wrench attack to scale to an entire society you have to send the gestapo to everyone's house whereas push-button attacks scale by default unbenownst to the victims and enable more nefarious systems to be built on top of them. In the USA this would mean interrogating some well armed citizens.
Lastly, you aren't forced to give up the key by any means. They can torture you to death and there is nothing they can do if you don't want to give up the key. There are some secrets in the game of love and war that are worth taking to - it's why spies are equipped with cyanide pills.
Missing a holiday is usually not such a bad price to save you from whatever the government is considering doing to you.
The point of the comic is pretty obviously to make fun of the expectations of cryptography geeks; you know, the sort of people who use 4096 bit RSA keys for the coolness factor. It is a stretch to imply it is suggesting that encryption is somehow futile.
The United States has famously shot and killed protesters in the Vietnam war era. They have dedicated torture facilities for people suspected, not even convicted, of terrorism. Police officers use lethal violence for no reason every month and rarely get more than a talking to.
In a perfect society, your point makes sense, but I don't see why the authorities in the real world would need to care about committing a worse crime.
You end up getting hit by a wrench though, that doesn't sound like it ends well for you.
If you're that much of a coward, you won't get hit by a wrench anyways because you will give your keys up immediately. But you will force your enemy to exert additional effort.
It works for the same reason locks on houses work against cops or criminals, despite the existence of lockpicking and locksmiths. There are various layers of physical security, and while no layer can prevent an attack absolutely they each increase the cost of an attack.
The system is only as secure as it's weakest layer.
So in a mixed information/physical system like a smartphone why should we allow the weak point to be the information system? To improve the information system we need only to rewrite the software, so the per-unit cost is nothing in the large.
Liberty is given up in inches, not miles.
The offenses of a regime at its apex would've led to it being stopped had they started out that way, but they didn't.
What you've hit on is the basic problem of treating privacy as a means to an end though: no level of it protects you from fascism, but it is a means by which fascism can be opposed - in many cases at personal cost to yourself.
In theory I have no secrets, and the contents of my phone or life if public would be of no consequence to me. In practice, when the regime starts flustering itself that I have no secrets for them to reveal the hopefully people will oppose it - or I get a decent warning that it's time to bail.
Sounds like something a coward would say, honestly.
Everyone thinks they're brave until they get punched in the face. The fact that a handful of terrorist attacks decades ago were all it took to push society into voting for control freaks who built a worldwide surveillance state to nanny them tells me all I need to know about how brave people really are.
Relevant news story: https://www.androidauthority.com/grapheneos-duress-pin-us-pr...
It sounds like he did give them the password, but it was the password to wiping his phone and not unlocking it. I'm surprised they didn't back up the device first.From what I understand he was not formally arrested at the time, just interrogated at the border. I am not familiar with US laws but from what I understand the device was not (yet?) considered evidence in an investigation. I imagine backing up might not be as easy an option without tearing down the device as the memory chip is no the device mainboard, so not something you can necessarily do on the side of the road or at a border without a formal warrant/investigation.
Border searches are special case in US law where the 4th amednment protections aren't as strong. See the EFF page about it for more:
https://www.eff.org/issues/border-searches
This is really an interesting case. Hope to see a ruling here. The edge cases are really interesting as well, like the fake pin on the back of the phone. I also wonder generally about the 'destruction' of data Wouldn't the government need to prove that there is no backup, because just making it more difficult (like hiding) would probably not call for the paragraph. Unfortunately for the rest of us the defence is based on more proven grounds. I guess only plausible deniability is helpful: I e.g. would love to see my trusted android space being empty/recreated on false password.
> The edge cases are really interesting as well, like the fake pin on the back of the phone.
"Your honor, I have the real pin memorized because I use it all the time, but since I can never use the duress code, I had to keep it somewhere handy."
Or
"Pickpocketing and phone-snatching is a real problem overseas, I put it there so that criminal would wipe the phone trying to get in, denying them access to things like my bank account."
Heck, those aren't just plausible, they might be a good idea.
> I'm surprised they didn't back up the device first.
There's no use in taking an image of the SSD and restoring it after a wipe. Data needed to derive the key encryption keys was wiped from the secure element. Separately from that, there's also additional data on the SSD needed to derive the key encryption keys which the TEE hardware will no longer consider valid.
Entering the duress PIN/password does the following:
* wipes TEE hardware keystore * wipes secure element hardware keystore * wipes the secure element other than Factory Reset Protection data which isn't used by GrapheneOS at this time * wipes the encryption metadata on the SSD with special wiping commands
The secure element data is inside the secure element's internal storage. TEE keystore keys are normally stored encrypted on the SSD with a hardware-based anti-rollback storage system to prevent reusing deleted keys. The secure element keystore is a lot more secure.
The most important data that's wiped is the Weaver table on the secure element. Weaver is the secure element rate limiting feature we describe in our post. It's implemented by the OS passing a dedicated hash of the initial key derived from the user's PIN/password. If it's the valid hash, the secure element provides a token needed alongside the initial derived key for the final key derivation. If it's not valid, it's a failed attempt wasting one of 20 attempts and triggering a hardware enforced delay.
It also isn't possible to simply image the SSD and then try to brute force the PIN/password due to the secure element rate limiting and the final key derivation done in the TEE.
It isn't the same as a typical disk encryption approach on a desktop, although GrapheneOS supports using a strong passphrase to avoid depending on the secure element rate limiting. GrapheneOS makes it convenient to use one via 2-factor fingerprint+PIN secondary unlock in After First Unlock state. It's the same as regular fingerprint unlock but with a PIN needed to complete it where incorrect ones count towards the limit of 5 attempts (reduced from 20 by GrapheneOS).
My trick there is not travelling to the US.
I carry a burner phone when travelling most of the time anyway. It has access to email only, 99% of which is in offline folders anyway.
The alleged charges seem nonsense - destruction of property to prevent seizure? First no property was destroyed, and second they could still seize it. But US courts are a coin toss so it may still work for the government.
It sounds like he did give them the password, but it was the password to wiping his phone and not unlocking it. I'm surprised they didn't back up the device first.
The duress password does not wipe the phone. It wipes the encryption keys from the secure element. The phone's storage is the backup, but it is worthless, unless law enforcement has an attack against AES that does not require a brute force attack (unlikely).
Oh please. That's not a real distinction. The phone as a unit, flash plus enabling chips, is wiped in an unrecoverable way.
And the primary copy is not a backup.
This site is called Hacker News :), people might just want to learn how it works technically, so I think it is worth mentioning technical differences.
Also, it does make a small difference in practice. Erasing keys is pretty much immediate, while erasing storage can take some time (especially for phones with larger storage), so the attacker could still try to power down the device in some way to avoid all storage gets wiped.
Going into detail about how it works: great.
Saying it's "italics-not wiped": bad.
It might be a real legal distinction, but probably not.
I'm not sure it would have been that easy for them to back it up.
Depending on his settings.
You can disable the usb port entirely if you like, so that it is only possible to charge the device by switching it off. Or enable charging only when unlocked etc.
Or if his device had rebooted I don't think it would be possible to extract anything.
So, technically, the border agents wiped the phone. I wonder how specific their request was of Tunick when they asked for the password.
Yes, it would be interesting if the question was formulated like "we're gonna need a password" and this ends up being a lawyerdog situation. https://blogs.illinois.edu/view/25/574827
Backup is useless without security chip.