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Evidence that the FBI can hack into private Signal messages on a locked iPhone
- IgorBog61650384 6y agoI don't think this should surprise anyone. The FBI has multiple methods for accessing locked phones: using physical exploits like those provided by Cellbrite, or through baseband attacks - i.e. first attacking the cellular modem and from there using an exploit to get to the main ARM cpu, or through exploits or backdoors in any app the phone had that do background refresh through the web while the phone is locked. I think the current status of infosec means that anyone that is the target of a nation state intelligence agency or counter intelligence agency can be hacked. The question if that is actually done or not depends on how interesting they are and the lawfulness of the action and not on technical capabilities.
- lawnchair_larry 6y agoYour understanding of baseband attacks is not correct. Having a baseband exploit would not facilitate this. Nor would exploits/backdoors in any particular app.
- sprayk 6y agoWhy couldn't a baseband attack facilitate this? It was shown at least as far back as 2017[0] that a program on a baseband could affect the memory of the application processor, and in 2018[1] that a specially crafted message can achieve an RCE on a baseband. Since then, cell modems have gotten even more integrated with APs. [0] https://comsecuris.com/blog/posts/path_of_least_resistance/ https://comsecuris.com/blog/posts/path_of_least_resistance/ [1] https://i.blackhat.com/us-18/Thu-August-9/us-18-Grassi-Exploitation-of-a-Modern-Smartphone-Baseband-wp.pdf https://i.blackhat.com/us-18/Thu-August-9/us-18-Grassi-Explo...
- lxgr 6y agoAs far as I understand, the isolation between basebands and the main SoC has also been improved (using IOMMUs etc.)
- xoa 6y ago>Why couldn't a baseband attack facilitate this? Because this is about the iPhone, where the baseband is just a USB peripheral. There simply is no DMA. iPads and Macs have DMA controls in place as well. There are other iPhone attacks for sure, but they have been fairly conscious about keeping the baseband isolated for a good long while. So it's less likely to be the vector. Apple didn't spend a ton of money on a custom security processor and OS stack just to let a 3rd party vendor firmware walk all over it. From page 41 of their old iOS Security Guide: >"To protect the device from vulnerabilities in network processor firmware, network interfaces including Wi-Fi and baseband have limited access to application processor memory. When USB or SDIO is used to interface with the network processor, the network processor can’t initiate Direct Memory Access (DMA) transactions to the application processor. When PCIe is used, each network processor is on its own isolated PCIe bus. An IOMMU on each PCIe bus limits the network processor’s DMA access to pages of memory containing its network packets or control structures." You'll notice in those papers you link, that "iPhone" and "Apple" do not appear as subjects of the paper. Cellebrite and the like are probably doing other things.
- IgorBog61650384 6y agoExploits are possible even without DMA. Windows had a slew of USB stack exploits, ranging from the serial and modem drivers to HID device and more. There have also been in the past (and probably still exist) exploits over serial lines, over I2C and SMBus, etc'. Not having DMA makes it much, much harder, but not impossible. So having the modem connected by USB does not make attacking through it impossible - how can you tell there are no bugs in the iOS USB stack?
- ostrophonics 6y agois partial AFU mode anything less than a backdoor?
- sprt 6y agoI suspect it's a needed trade-off between security and practicality. I have no idea how "needed" it is though, can someone shed some light on this? Also, couldn't Signal add their own encryption layer?
- tprynn 6y agoSignal could add app-level encryption, but who would this serve? Signal can't do anything better than what the OS/hardware provides in terms of encryption. Even if they let you specify your own signal-specific password/encryption key: * Non-technical users either won't use it, or will use a weak key * Technical users are better served by making sure their device is secure and hard-locked with a strong passcode (tip: 5 presses of the lock button on iPhone wipes in-memory encryption keys, essentially exiting "AFU mode")
- kuyan 6y ago> (tip: 5 presses of the lock button on iPhone wipes in-memory encryption keys, essentially exiting "AFU mode") Is this the same thing as holding down the lock button and one of the volume buttons on one of the newer iPhones? I'm referring to this doc: https://support.apple.com/en-us/HT208076 https://support.apple.com/en-us/HT208076
- tprynn 6y agoYes, it's basically a side effect of activating Emergency SOS. The five-press shortcut works on all iPhones as far as I'm aware. As the doc says: "If you use the Emergency SOS shortcut, you need to enter your passcode to re-enable Touch ID, even if you don't complete a call to emergency services. "
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- Jkvngt 6y agoThere’s a reason Rosenfeld needs your phone number and it’s becoming more obvious.
- neonate 6y agohttps://archive.is/EdcT6 https://archive.is/EdcT6
- DC1350 6y agoHow is it possible that the FBI has so much advanced stuff when I’ve never met a skilled developer willing to work for what the government pays? Are their tools developed by high paid contractors?
- notyourday 6y agoMost of skills required gov operations are done via companies holding government contracts. Those that work for government directly for a low pay compared to what they could get in the industry simply aren't smart enough to figure out how to work via a 3rd party for a much higher pay.
- fl0wenol 6y agoYes.
- Miner49er 6y agoThere's companies that sell exploits like this to governments.
- jaywalk 6y agoYou clearly didn't read the article, since they call out the two companies who supply this type of technology to law enforcement organizations.
- DC1350 6y agoI’m more interested in their compensation than how they get paid. I know lots of work is done by contractors.
- warent 6y agoI don't get this. Your original comment said "Are their tools developed by high paid contractors?" but now you're claiming to have already known. What exactly are you asking?
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- deleted 6y ago[deleted]
- everdrive 6y agoIf you own the phone, the messages are decrypted. This seems to be more about the phone access than anything to do with Signal, right?
- keyme 6y agoOf course. All these articles and "criticisms" of Signal started popping up right after the recent WhatsApp mini exodus. What a coincidence.
- TaylorAlexander 6y agoI mean it makes sense. People are concerned about data privacy on WhatsApp so they move to signal. Then the people who have always said “signal isn’t perfectly secure” must reiterate to the masses what that have said many times before.
- baxtr 6y agoMaybe your assumption that something dubious is going on can be eliminated by Occam's razor? Because: any business that gains in popularity will automatically also see higher press coverage.
- EGreg 6y agoJust like women in tech — or any male dominated industries — have proportionately more unfortunate encounters with men because each woman has more men around her to begin with?
- cyberlurker 6y agoWhere is the data that “women specifically in tech have more unfortunate encounters with men” than other industries?
- filoleg 6y agoIsn't it the case not just in tech, but literally in any field that is male-dominated? I strongly doubt that the problem you describe is any less prevalent in finance or academia, for example. Not a comprehensive list, of course, those were just two off the top of my head.
- selivanovp 6y agoThat’s why a sane person should’t trust any messenger, especially if it works in android/iOS/Windows. And Signal specifically works like a red flag for monitoring software- this user has something to hide!
- tobib 6y ago> And Signal specifically works like a red flag for monitoring software- this user has something to hide! Less accurate though with every new user.
- brandmeyer 6y agoUniversal encryption is a defense against blanket vacuuming of communications for later offline analysis. Its a defense against a massive parallel MITM attack against the world's communications infrastructure. Its not a defense against targeted attacks of individual devices.
- godelski 6y agoIn addition to this, I frequently hear people talk about how Signal would prevent monitoring of groups like those that stormed the capital. As if you can create a secret communication channel that members of the public can join but the FBI is unable to infiltrate. Signal and E2EE stop dragnets, not targeted efforts. Which honestly is exactly what I want and seems like what we want in a free and open society. Monitoring shouldn't be the default but only happen when there is a warranted reason to monitor, preferable with a literal warrant. This embodies the idea of "innocent unless proven guilty" but balances the ability to move from suspicion to evidence gathering and minimizes the collection of data of innocent people. It's not "if you have nothing to hide then you have nothing to fear" but "if you have nothing to suspect then you have no reason to search." I don't know how a dragnet doesn't violate the 4th amendment.
- nefitty 6y agoThis comment helped clarify a lot of my intuitions regarding privacy.
- BugsJustFindMe 6y ago> As if you can create a secret communication channel that members of the public can join but the FBI is unable to infiltrate. Back in the day people used to, hilariously, have MOTD notices on all of their illegal servers saying the internet equivalent of "You have to tell me if you're a cop".
- deleted 6y ago[deleted]
- banana_giraffe 6y ago
- deanclatworthy 6y agoWhy would criminals not use expiring messages? Bizarre that you’d go to these lengths to use e2e chat and then not expire your messages after say an hour.
- hnrodey 6y agoCriminals are quite often not the sharpest tools in the shed. Expiring messages, staying up on the latest hardware, etc.
- dredmorbius 6y agoCriminals who get caught, one should note. Sort of a reverse survivorship bias at play here.
- moftz 6y agoThe smart ones don't get their phones seized by the FBI
- girvo 6y agoAll the ones I knew did, for exactly this reason, and still didn’t speak too freely on it. Cant be too careful.
- csydas 6y agoBecause expiring/detonating messages are not valid security. Signal even warns of this: https://support.signal.org/hc/en-us/articles/360007320771-Set-and-manage-disappearing-messages https://support.signal.org/hc/en-us/articles/360007320771-Se... If Charlie is selling drugs to Bob and Alice, expiring messages don't help Charlie out if the others are finding ways to capture data on the screen before the message expires (which, is very common for very innocent, non-malicious reasons). Similarly, though I've not tested this with signal specifically, other chat apps' implementations of expired messages can be futzed with by simply disconnecting the phone from all network connections. People who need true privacy, regardless of the reason, aren't using chat apps readily available from stores since the apps only prevent passive snooping, they do nothing to help establish circles of trust. Such business is either conducted out in the open without concern for who sees what (you can see this in countless pictures online when people openly sell stuff like weed), or such business stays off chat apps completely because there's no way to validate who is holding the phone on the other end. The transactions occur indirectly using proven safe methods for the courier and buyer (dead drops, mail tricks, etc)
- exabrial 6y agoI hate be a spoil sport, but generally I don't need protection from the FBI, NSA, CIA. I need convenience to unlock my phone/laptop quickly with a fingerprint, even after a restart. XKCD nails this: https://xkcd.com/538 https://xkcd.com/538 I'm MOST concerned with Google/Facebook continuously circumventing laws and violating my opt-out preferences. I'd like to have a null advertising ID for instance. Can't do that. And besides, you don't own root access on your devices. Apple/Google does. To think that a userspace app is secure where Google/Apple controls the kernel, or even something basic as remote screenshots is sort of silly.
- sterlind 6y agothe US has problems, but the police won't hit anyone with wrenches to get them to talk. torture taints the evidence obtained. the reason spy agencies can do it is because they're not law-enforcement. that's why they have to use parallel construction, to launder the evidence trail.
- exabrial 6y agoThey're not going to hit you with a wrench... it's a comic. However, they will hit you will civil asset forfeiture, freeze your accounts so you can't pay lawyers, run your name through the news so you lose your job, jail you until your trial etc.
- reaperducer 6y agoI hate be a spoil sport, but generally I don't need protection from the FBI, NSA, CIA. Awesome. Good for you. However, there are people out there who are busy changing the world, holding the powerful to account, and generally being involved in society in ways that are less safe and more interesting than you do. This is about them, not about you.
- exabrial 6y ago> there are people out there who are busy changing the world It's kind of interesting to me to see the Apple bullshit propaganda being repeated on HN so many times. Tell me, do you have root access to your phone and are your binaries created from reproducible builds? Otherwise it is marketing wank.
- torwayburger 6y ago"..., stealing users from WhatsApp ..." Genuinely curious about this statement. Is it tantamount to theft if the user migrates by choice?
- beervirus 6y agoIt's just a figure of speech.
- torwayburger 6y agoBeing a figure of speech has little to do with the statement being factually incorrect.
- TameAntelope 6y agoYes it does, since it's not presented as factual.
- torwayburger 6y agoIt's written as a statement, not as a figure of speech. If it's not intended to be factual, it should be annotated as such. It literally claims theft as it stands, which makes the article seem juvenile in use of language.
- beervirus 6y agohttps://www.dictionary.com/browse/figure-of-speech https://www.dictionary.com/browse/figure-of-speech It doesn't have to be labeled in big flashing letters "THIS IS A FIGURE OF SPEECH" for reasonable people to construe it as a figure of speech.
- torwayburger 6y agoBeervirus is stealing my time by arguing nonsense. See? Clearly presented as fact by the language used and yet clearly it's nonsense. No label necessary.
- tsuru 6y agoI've had a hard time believing that this isn't government standard practice for an SSaS since Hushmail spoke about it in 2007. https://www.wired.com/2007/11/encrypted-e-mai/#:~:text=Hushmail%20uses%20industry%2Dstandard%20cryptographic,messages%20to%20a%20Hushmail%20account https://www.wired.com/2007/11/encrypted-e-mai/#:~:text=Hushm....
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- vzaliva 6y agoNice try, Facebook :)
- jb775 6y agoRather than hacking Signal itself, maybe they were able to access the iOS app preview files from the iOS app-switcher? I'd imagine the app-switcher (the feature when you swipe up to switch between recently used apps) works by overwriting a screenshot every time it's minimized. Maybe they were able to access this data directly or indirectly (or maybe even via iCloud). There's a setting in Signal where you can hide the screenshot in the app-switcher, but could still be triggered and stored somewhere. Or maybe they just got lucky and one of the guys had it disabled.
- agret 6y agoShould read the article before you comment next time ;) There is a screenshot in there showing it is directly parsing the Signal sqlite database. I am guessing on his device he had not set an access passcode to the Signal app so no key was required to decrypt the local message cache. Towards the end of the article the Signal creator hit the nail on the head saying this is a phone security issue and nothing to do with Signals security.
- alexpc201 6y agoAn interesting idea for an app which resets the iPhone after some idle time, or if iPhone loses contact with the apple watch. To prevent AFU exploits.
- ampdepolymerase 6y agoThe Signal app, to the best of my understanding, does have a built in dead man's switch in the form of the PIN system. You can apparently set the time range in the settings.
- madars 6y agoSignal PIN currently serves a different purpose: it enables registration lock, which is a defense against number porting attacks. https://support.signal.org/hc/en-us/articles/360007059792-Signal-PIN#manage_registration_lock https://support.signal.org/hc/en-us/articles/360007059792-Si...
- kart23 6y agoAfter holding down the power and volume buttons on an iPhone, biometrics will not work, and the phone will require a passcode. Does this still count as AFU?
- sneak 6y agoI think a better fix for this issue (because, of course, they can seize the other party's phone) is to use Signal's expiring/disappearing messages, so that they are (presumably) erased from both devices after the specified period of time. I wonder if the method of "disappearing" the messages used by the app is vulnerable to forensic analysis or not.
- icelancer 6y agoYeah, not using disappearing messages with Signal is just asking for this type of thing to happen. It's the number one reason I even use it in the first place.
- qwerty456127 6y agoBut would it do that and admit that when it's not really worth? Din't you have to be really really notorious for them to use this kind of evidence in a court? If I were them and could decrypt something I would prefer to keep this fact secret.
- incompatible 6y agoPresumably a defence lawyer could ask for demonstration of the technical details: prove that they have the ability to obtain such evidence and didn't just fabricate it.
- qwerty456127 6y agoThen everybody would know they can and no people of those they could want to hunt would rely on the compromised technologies anymore. There are rumors they can even decrypt HTTPS but I bet they would do their best to hide that if they actually could.
- deleted 6y ago[deleted]
- GizmoSwan 6y agoI would be surprised if they did not have a back door in the chip's firmware but so far nobody had found or talked about it. They can intercept post de-encryption data if they hack the firmware during design period and get access.
- upofadown 6y agoSignal uses a sqlite database with an encryption extension for any long term storage of data. The key to this database is kept in whatever the phone uses for key storage. So if you break the phone you get everything including the old messages. The moral is to not keep the old messages around and delete them after you are done with them and hope they actually end up deleted. This is a hard problem simply because of the medium. If you do encrypted instant messaging you need to have everything fairly exposed all the time. You simply can't make it as secure as something like encrypted email where you can lock down everything very strongly and only unlock it when you are in a safe environment. The extra level of security also means that keeping the old messages around is a lot less risky.
- bluesign 6y agoActually this is not correct, you can also use key which is destroyed on lock.
- upofadown 6y agoFor instant messaging you need to be able to receive messages even when the phone is locked. So the key material can't be destroyed and must be left exposed. You could encrypt old messages separately, but the result would end up being very inconvenient.
- dwighttk 6y ago> For instant messaging you need to be able to receive messages even when the phone is locked. Why?
- bigiain 6y agoYou can receive encrypted messages and store them while locked. You only need the key material when reading the messages, which then uses the apps unlock pin to retrieve the key material from the Secure Enclave. Quite how Signal deals with notifications I’m not sure, perhaps your right and the encryption key s persistent while the app is in the background so it can show you the sender and message on the Lock Screen? But it doesn’t _have_ to be that way. Wickr (which I trust way less than Signal) seems to at least have its UI set up to imply that’s what it’s doing.
- bluesign 6y agoThis seems to be problem with Signal to be honest. AFAIK you can always use more secure data protection classes for your database[0] They are using the default one, which is allowing AFU attack. [0] https://support.apple.com/en-ca/guide/security/secb010e978a/1/web/1 https://support.apple.com/en-ca/guide/security/secb010e978a/...
- pseudo0 6y agoWould switching to say, Protected Unless Open have a negative performance impact? Otherwise, it seems like a kind of obvious oversight not to use a more restrictive data protection class. I'd be curious to know the Signal team's rationale for using PUFUA.
- bluesign 6y agoActually i just checked their entitlements on github and it is set to NSFileProtectionComplete. Seems stranger than I thought edit: After diving into code, they are using NSFileProtectionCompleteUntilFirstUserAuthentication for their DB file, probably they have some reason
- ilyas121 6y agoAny reason why they can't access it from icloud backups?
- dwighttk 6y agoAccess what?
- NamTaf 6y agoI wonder if Apple's relentless march towards eliminating all physical ports on the phone is at least in some small part an attempt to harden against these GrayKey / Cellebrite tools that can attack the phone. I am not particularly familiar with them, but having previously been someone who jailbroke my phone, several of the exploits used were originally delivered via plugging the phone in to another device, i.e. through the data port on it. Elimiating this may be to them a way to harden the phone against this, for both better (these tools) and worse (the JB scene). This of course does not prevent remote or semi-remote wireless attacks, such as through the cellular baseband.
- 2OEH8eoCRo0 6y agoWhy are iPhones so easily hacked?
- anm89 6y agoThis is a totally dishonest article. Of course encryption doesn't work if you can compromise the end user who already has the keys. I don't think anyone would ever claim it did.
- xyzal 6y agoIdea for an app, which would probably require a rooted Android: new USB peripheral detected (incl. charger) when screen locked => power off. I guess it could at least frustrate some of the data collection efforts.
- einpoklum 6y agoAre there smartphones where all data - except some write-once installed programs - is stored encrypted, with a complex enough key to not be easily breakable by the authorities, on one hand, but being reasonably usable by you, on the other hand?