One of the FBI’s Major Claims in the iPhone Case Is Fraudulent

https://www.aclu.org/blog/free-future/one-fbis-major-claims-iphone-case-fraudulent

by danielsiders • 10 years ago

759 252 10 years ago

pbkhrv3• 10 years ago

How practical is it to remove-restore-replace the NAND chip every 10 tries if you have to search through millions of combinations?

jessaustin3• 10 years ago

Presumably you'd only have to remove it once, then install it in an easily-controlled circuit that would selectively connect it back to the rest of the phone?

drakenot2• 10 years ago

If the user was using a 4 digit pin code it would only be 10,000 combinations.

voxic11• 10 years ago

Where do you get the millions of combinations figure?

CIPHERSTONE• 10 years ago

Maybe it was a type and he meant to say: >You see, a six digit passcode has one million possible combinations instead of 10,000.

pbkhrv3• 10 years ago

for passcode, iPhone supports 4-Digit numeric code (10k combinations), 6-Digit numeric code (1 million combinations), "custom numeric code" (arbitrary length, millions of combinations), or "custom alphanumeric code" (arbitrary length, millions of combinations)

RickHull• 10 years ago

If it turns out that the auto-erase feature is on, and the Effaceable Storage gets erased, they can remove the chip, copy the original information back in, and replace it. If they plan to do this many times, they can attach a “test socket” to the circuit board that makes it easy and fast to do this kind of chip swapping.
If the FBI doesn't have the equipment or expertise to do this, they can hire any one of dozens of data recovery firms that specialize in information extraction from digital devices.

ikeboy2• 10 years ago

Are there any data recovery firms that advertise the ability to do exactly what the FBI wants here?

CamperBob22• 10 years ago

One obvious workaround would be to emulate it with an FPGA.

kabdib4• 10 years ago

Heck, the FBI could also disable writes to the chip, or simply interpose some logic that pretends to write, but actually doesn't (a non-write-through cache :-) ).

That is, if the secrets in question are on that NAND chip.

drakenot2• 10 years ago

For this device, with no Secure Enclave, I believe they are on the NAND chip.

kabdib4• 10 years ago

Heck, there are probably 20 companies with a Silicon Valley zipcode that could do that work, then. And a few in LA. I know people who could do this in their garage (and that's not hyperbole).

jonknee6• 10 years ago

They aren't, the key is burned into the chip. You could decap it and try and get at it that way, but that also runs the risk of destroying it and losing all hope of data recovery.

an_account2• 10 years ago

I think you're thinking of newer iPhones.

loumf• 10 years ago

I wouldn't be so sure the FBI knows this. Apple certainly does -- if they told the FBI, why didn't they also put that in their letter?

ebbv2• 10 years ago

If the FBI's technical teams can't figure this out they should all be fired and it's all the more reason we shouldn't trust them with back doors into anything.

officialchicken2• 10 years ago

Obligatory ACLU and EFF donate links, "Freedom isn't free":

https://action.aclu.org/secure/become-freedom-fighter-join-a...

https://supporters.eff.org/donate

joshstrange• 10 years ago

Obligatory you can donate to the EFF via Amazon Smile:

EFF: http://smile.amazon.com/gp/chpf/search?ie=UTF8&q=Electronic%...

ACLU: http://smile.amazon.com/gp/chpf/search?ie=UTF8&q=ACLU

And Chrome plugin that I use to force the browser to the smile site: https://chrome.google.com/webstore/detail/smile-always/jgpmh...

I've never used this firefox one but here's a link to a similar one for FF: https://addons.mozilla.org/en-US/firefox/addon/amazonsmilere...

sosuke• 10 years ago

I only recently learned about Amazon Smile. Awesome stuff!

rqebmm• 10 years ago

"Freedom isn't free":

Is the suggested donation a buck oh five?

officialchicken2• 10 years ago

Could be, depends on how you value it.

sathackr2• 10 years ago

With 14 million combinations just in a 4 character alphanumeric(upper/lower/numbers) password, I would think they would start to encounter flash reliability issues re-writing this "Effaceable Storage" long before the password could be broken.

This would also slow down their attack considerably.

I disagree that the claim is fraudulent.

Titanous2• 10 years ago

At that point they can swap out the flash chip for a new one, new chips can be obtained easily. Also, the PIN is 4 numeric digits, no alpha characters.

tyre• 10 years ago

I believe the passcode is only 4 numbers, not alphanumeric.

athenot• 10 years ago

The passcode can be alphanumeric. It's user-configurable.

http://www.engadget.com/2014/03/05/how-to-set-up-a-complex-p...

ebbv2• 10 years ago

iPhone 4-digit codes are not alphanumeric, they're digits only so there's only 10,000 combinations.

Johnny555• 10 years ago

by definition a 4 digit code is a 4 digit numeric code, but I haven't seen a definitive source saying that the phone is secured by a 4 digit PIN, as the iPhone allows longer PIN's as well as alphanumeric passcodes.

http://www.macrumors.com/how-to/create-a-more-secure-passcod...

geographomics3• 10 years ago

Interesting technique, but it doesn't remove the long interval between permitted passcode attempts - an equally important problem for brute-forcing.

So the FBI would most likely still require Apple's assistance in this.

albinofrenchy3• 10 years ago

Isn't it just a 4 digit pin? Even if they input a pin per minute, that is slightly under a week, worst case scenario.

kyrra• 10 years ago

iOS9 started defaulting to asking for a 6-digit pin now (though you can still do 4-digit). So it may depend on when the phone was setup.

iLoch4• 10 years ago

No, it uses an exponential back off.

jperras2• 10 years ago

If you can copy the contents of the NAND memory to one chip for testing, then you can copy it to a hundred chips and parallelize the process, assuming I haven't misunderstood the hardware issues at hand (not my specialty, to be fair).

The exponential backoff of attempts is not really an issue in that case.

brk2• 10 years ago

This was my thought too after reading this article.

Part of this relies on the specific iPhone 5c from the shooter, because of the per-device hardware key. They ultimately need to unlock that specific phone, with the NAND data intact, in order to read the contents.

But, if the passcode is stored in NAND and validated only against user input they could duplicate the NAND and parallelize the process. If any part of the user code check involves the hardware key, then it wouldn't work.

geographomics3• 10 years ago

You can't parallelise it like that, because the passcode check relies on an unreadable AES key (the UID) that is unique to that particular iPhone.

nickysielicki3• 10 years ago

Or you could just extract the UUID (though others are claiming that's not possible; I'm skeptical but don't know) and throw the iPhone in the garbage as they use a distributed supercomputing cluster to decrypt it.

devy2• 10 years ago

Interestingly, this is the EXACT advice [1] given at the Apple + FBI @ U.S. Congressional Hearing on March 1st from California congressman Darrell Issa (R).

Congressman Issa was previously the CEO of DEI, a car security and audio equipment company. He is possibly one of the most tech-savvy members of U.S. Congress and happens to be one of the wealthiest as well [2].

The Congressional hearing video footage is here, the suggestion was proposed at 1h23m 13s in.[3]

[1] http://qz.com/628745/i-have-no-idea-the-fbi-director-at-the-...

[2] https://en.wikipedia.org/wiki/Darrell_Issa

[3] https://youtu.be/g1GgnbN9oNw?t=4993

cwkoss• 10 years ago

What is the A6's trusted source for time? Does it have an internal clock, and if so, what happens when it loses power?

emcq• 10 years ago

Maybe their exists experts that can get this right every time but there are significant risks to damaging a chip desoldering and resoldering. It's not just removing a through hole capacitor.

devy2• 10 years ago

Disclaimer I am no electrical engineer and have had limited experiences soldering components on circuit boards. But from all the tutorials I've been through, I agree. There are risks of damaging the NAND chip while desoldering and/or re-soldering chips on the board. Since there is the only piece of hardware with the information, perhaps the Feds aren't going to risk the chance of destroying the evidence all together after all they made the mistake of changing iCloud password already.

timv• 10 years ago

Yet the FBI's official plan is to get Apple to assign a few developers to put together a custom version of iOS that they trust will overcome all risk of erasing the device.

Is there a reason we should have confidence in software engineers rather than electrical engineers?

keithnz• 10 years ago

sw can test it on another phone till they get it right....EEs can only practice on another phone, if they screw up on the actual phone, it's gone burger

pwyll• 10 years ago

This. The chip needs to be desoldered, cleaned (remove a layer of epoxy resin) and then finally reballed (secure a 0.3mm ball of solder on each of the > 64 connectors) just to get the on the chip reader.

Once you've done that you need to reverse the process.

I've done a few of these and they still scare me. Its not a trivial process.

iLoch4• 10 years ago

I wonder if the FBI has checked for any ways to circumvent the passcode screen using software bugs.

Edit: Not sure why I got downvoted. I can currently circumvent my keyboard passcode with a number of steps, and I'm on iOS 9. Steps to try for yourself:

Edit: Ok I've been tricked. The steps below are unnecessary as the first step actually unlocks your iPhone in the background. ¯\_(ツ)_/¯ The fact remains though that these bugs have existed in the past and may exist on the device the FBI wants to unlock.

1. Invoke Siri, "what time is it?"

2. Press the time/clock that is shown

3. Tap the + icon.

4. Type some arbitrarily long string into the search box. Highlight that text and copy it.

5. Tap on the search box. There should be a share option if your device is capable. Tap the share option.

6. Share to messages.

7. Press the home button.

Congrats, you're more effective than the FBI.

rm_-rf_slash• 10 years ago

This works. You just scared the shit out of me. Well done.

Nadya• 10 years ago

If your device is completely up to date, shouldn't this not work? The SiRi-on-lockscreen vulnerability is nearly 6 months old by now.

rail2rail• 10 years ago

Whoa.

knd7752• 10 years ago

Data is still encrypted in that state. The passcode screen is not what is preventing access. That is how it works in Android (where a lockscreen is just an app that is locked into the foreground), but not iOS. Bypassing the iOS passcode entry screen gets you to a weird limbo-like state where a lot of thing don't work. I don't recall what that state is called.

kenferry• 10 years ago

For more on this see "File Data Protection" and "Data Protection classes" in https://www.apple.com/business/docs/iOS_Security_Guide.pdf .

The default protection class is "Protected Until First User Authentication". This means that unless an app says something more specific, the key required to read a file is not available between reboot and the first time a phone is unlocked.

tuxracer• 10 years ago

This is not accurate regarding Android http://www.zdnet.com/article/google-now-requires-full-device...

prdonahue• 10 years ago

Just tried this. No time/clock icon shown.

jonknee6• 10 years ago

Congrats, you just unlocked your device with TouchID.

laxatives• 10 years ago

There's this neat trick that can get you access into all of your bank accounts and credit cards. You can even get access if you forget your username and password.

look_lookatme2• 10 years ago

Hrm, didn't get a "Share" button.

liquidise• 10 years ago

I never get the Share option on 9.2.1 using a 6. I don't doubt this works on a number of OS/device combos though

iLoch4• 10 years ago

Yeah I'm on 9.1 with a 6.

zkhalique• 10 years ago

On step 5, I don't see any share option.

matthewmcg• 10 years ago

Interestingly, this works on my 6s when I press the home button with a finger that is registered for TouchID. I can't add a new clock when I use a different finger. That suggests that on my phone, at least, I'm really just silently unlocking the phone with Touch ID at some point in following these instructions--probably when I press the home button.

TouchID is so fast on the 6s, it's easy to unlock it without realizing you're doing it.

asd• 10 years ago

This has been debunked.

https://www.youtube.com/watch?v=2zOEoIV5YGI

tehwebguy2• 10 years ago

Share option doesn't show up for me on 9.2.1 with the phone locked, does when it's not locked.

mikeash8• 10 years ago

I got lost on step 5. I'm not sure where the share option is supposed to appear or why it would, but it doesn't for me.

On step 7, are you sure you're not also unlocking your phone with Touch ID when you do that?

filipm• 10 years ago

You're unlocking your iPhone using TouchID. Try this using a finger not registered for TouchID and the 'Share' option won't show.

It's a hoax.

nicoles• 10 years ago

Try accessing Siri with something that isn't registered with touchID (like a friend's finger) and this doesn't work. I think the steps have nothing to do with it, and it has more to do with you unlocking the phone with touchID when you summon Siri.

burritofanatic• 10 years ago

The share button will appear only if you use your thumb to invoke Siri. Try doing it with your knuckle to start.

albinofrenchy3• 10 years ago

Anyone else a little surprised that apples security feature here is so easy to sidestep? I'd have thought, in the least, that any such keys were stored in the main processor without external read/write capabilities.

brk2• 10 years ago

No, I'm not that surprised. I think this feature is intended to protect your personal data from the casual iPhone thief or to minimize risk if you lose/forget your iPhone somewhere. I don't think it was intended to be a secure-from-governments kind of features.

hollander• 10 years ago

Guess again - it is! It's a work in progress, and on the 6S it has improved a lot with the secure enclave in its own chip. It seems it will get even better, with encryption in the icloud as well.

The SE uses a different key for each app, so even if you can decrypt one key, you only get data from one app.

Titanous2• 10 years ago

The feature exists to protect against less sophisticated attacks. It's not necessary, as setting a long alpha-numeric passphrase will mitigate brute force attacks.

nickysielicki3• 10 years ago

It's a cheap phone from a couple years ago. This world is moving fast.

eridius4• 10 years ago

FWIW, it's not easy to bypass on devices with TouchID. The Secure Enclave manages the process there, and it's designed to be resistant to tampering so you can't use this trick with it.

mikeash8• 10 years ago

It looks likely that the Secure Enclave has no storage of its own, so this same attack would still apply.

What would make you secure here is having a password sufficiently long and complex to make brute forcing infeasible. Touch ID facilitates that by making it practical to use the device even with a strong password set. But if you have a four or six-digit passcode set on such a device, then this technique should still work fine.

DrJokepu• 10 years ago

…yet it's clearly more than enough to stop the FBI.

jonknee6• 10 years ago

Not at all, I think it's pretty great that they're encrypted by default. Plus, newer iPhones are even more secure (with the dedicated Secure Enclave).

codeonfire2• 10 years ago

The device is evidence, so all of you saying they can just start desoldering things and such need to think about that. What is the first thing a defense attorney would say if the data were to be used in a criminal trial? That's right, "the FBI replaced the memory chip on the phone with one they wrote their own copy of the data to." That is only after they potentially permanently damage the device and data.

Osiris• 10 years ago

Can't the same be said for when law enforcement takes images of hard drives? That happens all the time. There are procedures for maintaining chain of custody that are required to verify these things.

codeonfire2• 10 years ago

Hard drives have a universal interface for reading out their contents without modification. Most jurors would understand that. Many jurors would equate drastically modifying a device as tampering. Chain of custody doesn't matter. What a juror thinks is what matters.

TrevorJ• 10 years ago

That's why chain of custody is a thing. That argument could be made for anything, even physical objects can be tampered with.

TheDong• 10 years ago

And yet, there's no issue with "We'll let apple take the device, flash a custom OS onto it, and allow us to make attempts remotely while not having physical access to the device".

That's what they're asking for. Part of the FBI's argument is that they need the information for safety of our country, not specifically for the trial.

wl2• 10 years ago

The FBI specifically asked for a version of iOS that would be loaded into memory and not modify any of the information on the flash. One of Apple's arguments about why the request is an undue burden is that iOS doesn't normally work like that and it would take a lot of effort to make it work like that.

rhizome• 10 years ago

Isn't the FBI's position that the FBI will have physical possession of the device at all times?

throwaway_xx9• 10 years ago

Well, yes and no.

The owner is dead, so the phone data is not needed for a trial against the owner.

It might be evidence against "co-conspirators" - sadly, we have a vindictive, lawless government now that likes to go after former roommates and acquaintances.

malka• 10 years ago

The argument "the cops planted the evidence" usually does not go well by the judges, unless you have very very strong evidence that tamper DID occur.

fnordfnordfnord• 10 years ago

What criminal trial? The criminals are dead. Yeah, I know, James Comey said that maybe there's another criminal; spare me, I ain't buying it.

Also, you hire an expert to testify as to the technical details. It isn't perfect, but it is what it is; and anyway, the first thing a defense attorney will say/do in the case that the FBI prefers is to cast doubt upon the integrity of anything the FBI finds after all of the screwing around with it that's been done.

takeda• 10 years ago

Evidence to what? Both of them are dead, also this was work phone.

There's nothing interesting there.

tylercubell• 10 years ago

It seems like there are several articles and security experts out there explaining how to recover data from a locked iPhone as if it were a cakewalk but where is one example of a complete soup-to-nuts case study on unlocking the same model phone as the San Bernardino shooter?

If you want the American public to believe the FBI is making fraudulent claims, show demonstrable proof that it can actually be done instead of all the talk and theories.

ismyrnow• 10 years ago

^this

JaRail• 10 years ago

This article seems wrong to me. I don't know a ton about the iPhone's specific implementation. That said, I was under the impression that these systems all worked similarly to the PC's TPM. Essentially, the encryption key is stored in a chip that acts as a black box. That chip is manufactured in such a way that makes it extremely difficult to extract data from. You can't simply copy it. You'd have to take it apart, inspect it with a microscope, and hope you don't destroy the data in the process.

The OS should set the security level initially. The TPM would enforce it. You can't modify the OS to make an attempt without it counting against the initially configured limit.

https://en.wikipedia.org/wiki/Trusted_Platform_Module

zwerdlds2• 10 years ago

Not for the 5S. The iPhone TPM (or "Secure Enclave") is available on the A7 processor and above. The 5S includes an A6.

DoritosMan• 10 years ago

I think you mean the 5C.

makomk• 10 years ago

Some of the critical encryption keys are stored in the main A6 processor and incredibly difficult to extract, which is why you can't launch offline brute-force attacks - however those keys are read-only and initialized at device manufacturing time. All the volatile data is in the external flash chip. I'm not even sure if the Secure Enclave has its own flash on newer devices that have one.

jwildeboer• 10 years ago

"I don't know how stuff works but I think this is all wrong" uhm. Well.

ChuckMcM• 10 years ago

Seems like a pretty articulate explanation of what is going on here. Of course I realize that my confirmation bias will cause me to see articles more in line with my way of thinking as 'right' but I've also worked with NAND flash devices and believe that the chip[1] they use in the phone does not have any sort of protections on the NAND flash itself, you should be able to just drop it into a test fixture and read it out.

[1] http://toshiba.semicon-storage.com/info/docget.jsp?did=15002...

croddin• 10 years ago

Apple said that could sync the data if the AppleID password wasn't changed. Can Apple just revert the AppleID account on their servers to a backup with the old password hash (or however it is stored)? Why wouldn't this work? Has something on the phone changed because of the password change or is Apple unwilling or unable to revert the AppleID account?

chime2• 10 years ago

The local device could have cleared the stored password if the remote server rejected it even once.

an_account2• 10 years ago

I doubt it based on my past experience.

After I changed my iCloud email/password my phone tried to use the old one for months, and I had to escalate the issue high up Apple Support to get it fixed (you can't erase your iPhone without proper iCloud credentials if findmyiphone is enabled). That also involved my email, so it was slightly different.

nkurz2• 10 years ago

Could have, and perhaps should have, but I haven't seen anyone claim that it actually does delete the stored password after a failure. And it would be awkward if the automatic backup stopped functioning and required manual intervention after each intermittent network failure. It should be fairly easy for someone with an iPhone to test and find out.

jessaustin3• 10 years ago

Can Apple just revert the AppleID account on their servers to a backup with the old password hash?

If it were just a password hash and Apple still had that hash, then probably so. Is that actually how this information is stored? ISTM it could be something more complex. The system was not designed to support the FBI's intended use, so the fact that Apple could have logged and stored all sorts of things doesn't indicate that they did.

revelation• 10 years ago

The ACLU is not wrong, they are right in the technical sense.

But I very much doubt you would practically manage to remove that NAND chip and replace it very often on that umpteen layer ultra thin board. Instead, remove it once and stick it in a test fixture, then try brute forcing it.

edraferi2• 10 years ago

"Technical correct... the very best kind of correct!"

The bigger question here is: do you really want law enforcement to hack into things as standard procedure? They certainly don't. It's difficult, expensive, slow, and worst, unbound by law. It's a world where your privacy is exposed based on the federal hacking budget rather than a judge's opinion about your potential criminality.

It's much better for law enforcement to be constrained by law than technical ability.

payne92• 10 years ago

This attack was already widely discussed here, last week: https://news.ycombinator.com/item?id=11199093

toyg• 10 years ago

I have to say, whoever at the FBI decided this was the right case to push their new doctrine, could have done his/her homework a bit better. Technically speaking, this is the last iPhone you can actually crack without assistance from Apple. They are making it harder for themselves. They only have to wait for another major incident, retrieve (or plant, why not) an iPhone 6 from the scene, and do it again, this time for real.

Unless they are trying to pre-empt something else (like the recently-touted shift to "devices even we can't access" from Tim Cook, which may or may not be simple advertising), they just picked the wrong time to stir this particular pot.

mentalpiracy• 10 years ago

This case isn't just about Apple though. If the FBI wins this case, it becomes a precedent that can then be turned around and used on ANY hardware or software company in the future.

CamperBob22• 10 years ago

Which is why it should have been important enough to them to wait for the next 9/11 or similar incident.

Waving around the proverbial pipe wrench for a case this ambiguous is just stupid. They're just as likely to have it taken away from them altogether.

Gratsby• 10 years ago

this is the last iPhone you can actually crack without assistance from Apple.

That's being pretty liberal with words. It's more difficult to crack more recent versions, but saying it's impossible is putting too much faith in the creators of the device and too little in determined people who would want in.

steveax• 10 years ago

I suspect the main driver in picking this case had nothing to do with the technical details and everything to do with the emotional aspects. The general public won't follow the technical bits and the emotional appeal of the case (terrorists! scary!) has clearly been a boon.

lisper16• 10 years ago

This is really annoying. I wrote a blog post last week making this exact same point, posted it here, and it promptly got flagged to death, most likely by the same people who were commenting that I was "absolutely, totally wrong".

https://news.ycombinator.com/item?id=11199093

Nice to be vindicated though.

c3t0• 10 years ago

Thanks for bringing it up. Last week I read your article and I found it very interesting.

You did receive harsh RTFM comments (stark contrast with the tone of the comments on this thread).

Glad that you can see your work corroborated.

bduerst• 10 years ago

If it's any consolation, you're faster at describing this than the ACLU.

Hasn't it always been known, since the beginning of this issue, that this was a penetrable 5c phone and thus a red herring for the FBI's request?

lisper16• 10 years ago

It has been known in the abstract, but AFAIK I was the first to publish a specific attack. (Not that I really claim that as much of an accomplishment. Sometimes it's hard to navigate the line between educating people and insulting their intelligence, particularly when it comes to security.)

look_lookatme2• 10 years ago

Other people have brought this up but in a kind of hand-wavy way.

https://www.lawfareblog.com/how-destroy-pandoras-iphone

vatotemking• 10 years ago

The author is absolutely, totally wrong.
I flagged the article, as the entire argument is predicated on a factually false premise.

Wow those comments are harsh

Godel_unicode3• 10 years ago

Not inaccurate, however.

timr7• 10 years ago

To be fair, this isn't an especially relevant argument, even if it's true.

The FBI isn't going to rip open a phone, unsolder a chip and risk destroying the device, when it can do what it's done successfully, many times in the past, and ask Apple to unlock the phone for them:

http://www.npr.org/2016/02/22/467602161/the-seeds-of-apples-...

This thread is a real-world demonstration of the XKCD comic about pipe-wrench security:

https://xkcd.com/538/

Nerds think that proving that there's some theoretical, high-tech attack against the this specific phone means that the FBI should therefore lose. But that's irrelevant. This case is about the pipe wrench.

csydas• 10 years ago

Well, no, I think it's still very relevant.

To use the classic XKCD comic, the crux of the case is that FBI is the one arguing the first panel (i.e., some bogus magical encryption we can never break), and because of that claim, they need to be able to compel Apple to compromise the security features using the old wrench trick.

The reality of there being practical alternatives for the FBI to pursue should give pause as to whether they can compel Apple to compromise the security features, and arguably the method described/discussed is indeed very practical.

All in all, it's less about the FBI's ability to do any of this and instead more about "should be the allowed to force a company to do something like this?". By demonstrating the claim that it's impossible to proceed without Apple's help is not true, I would think it should give pause to any court as to how to rule, since the implication of the ruling is pretty big.

davmre• 10 years ago

It may not be relevant legally. But it undermines the (already very flawed) PR argument that Apple is enabling terrorists by not unlocking this specific phone.

Forcing the FBI to admit that their real objective is the general power to hit people with pipe wrenches seems like an important step.

acqq• 10 years ago

The linked article quoting former NSA person is wrong, Apple never unlocked encrypted iPhone 5C before, there are enough articles about the fact that for the previous demands no new software was needed, just data copying.

agwa2• 10 years ago

No, there's an essential difference between your post and the ACLU's: you suggested that the FBI would be able to brute-force the key off-chip, which is not true because the encryption key is derived in part from the device ID, which can't be extracted. This is not what the ACLU/DKG is suggesting - they are suggesting making a backup of the flash storage and restoring it after the auto-erase kicks in. The decryption would still happen on the iPhone itself.

Granted, you updated your post to suggest what the ACLU is now suggesting, but that was after the commenters correctly criticized your post for being wrong.

lisper16• 10 years ago

You must not have read my original post very carefully:

"they could use a copy of the chip to try five different PIN codes, and then replace the chip with a fresh copy of the original and try five more"

I don't know how I could have made it any clearer that I was proposing an attack on the PIN, not the key.

andromeduck4• 10 years ago

He said mount on their own hardware but that doesn't preclude using the original chips as part of the setup.

kordless2• 10 years ago

So you are annoyed someone who was wrong to begin with said you were wrong. :) I'm happy you were right!

lisper16• 10 years ago

No, the annoying part was being flagged to death, which cut off the discussion. I don't mind people telling me that I'm wrong. Sometimes they're right (but not this time).

orik• 10 years ago

do you think they could back up the nand chip and replace it with a read only nand chip with the same memory, and then try to unlock is as much as they want?

lisper16• 10 years ago

I don't know, but it's fairly pretty to find out. Just try it. I don't have the skills to desolder a surface mount chip but I personally know people who do. It would probably cost about $1000 to buy an iPhone and hire one of these people to do the experiment.

tremguy• 10 years ago

Pretty sure it would throw some kind of low level error as that would disable all kinds of basic IO.

TazeTSchnitzel3• 10 years ago

AIUI your blog post was nonetheless wrong. As the OP explains, there are multiple layers of encryption.

The first is at the hardware level, performed by the SSD itself.[0] It encrypts all data on it with a key stored in rewriteable memory. By changing the key, you can "erase" the drive. The FBI could backup that key if they wanted to undo the "secure erase" feature.

However, this is not the only layer of encryption. The second is done in software, performed by iOS. It encrypts all user data with a key derived from the user's passcode and a unique key burned into the chip. The FBI cannot get past this layer, and this is what they wanted Apple's help for.

You were right in that the FBI could trivially get past the first layer of encryption, but it's not the one we care about. There's more than one layer.

[0] Or rather, by the flash controller. At least, I assume it is. It might actually be an iOS software feature too, but the OP's description reminds me very much of how some SSDs implement secure erase. Whether it's actually done in hardware or software is immaterial, anyway.

lisper16• 10 years ago

The FBI cannot get past this layer

Yes, it can, and I explained exactly how in the original post. It's true I got some of the technical details wrong, but the substance of the post was and is correct.

superuser22• 10 years ago

FBI didn't demand help with that layer, it demanded a way to bypass auto erase. They intended to perform the brute force of the 4 digit PIN themselves. Sure, they wanted to be able to enter PINs electronically, but they could just as easily have an intern sit there and enumerate the 1000 combinations once auto erase was disabled.

retrogradeorbit2• 10 years ago

Hacker News filled with people who don't know what they're talking about but talking like they are infallibly right? Say it isn't so!

Your real issue was going up against the cult of Apple fanboys that hang out here. You will find this response with anything that remotely suggests that Apple isn't perfection.

You can see them still getting huffy in the responses to this comment.

lisper16• 10 years ago

But I wasn't even being critical of Apple, I was being critical of the FBI! I thought that would go over well here.

StreamBright2• 10 years ago

Well, HN is -just like any other community- biased and also suffers from echo chamber problem. Even if it is much smaller scale than any other online forum, still there is a chance for getting down voted even though your are absolutely 100% right about something and most of the down voters are wrong. You can either live with this and just ignore it or getting annoyed by it. I am not sure if this is going to be fixed or it needs to be fixed at all.

lisper16• 10 years ago

The problem is not so much the voting and the community, but the extreme non-linearity of the flagging mechanism. Getting flagged is mostly invisible until you cross a threshold and then -- poof! -- your article is dead. It was intended to keep spam and kitten pix off the front page. Vouching was introduced as a counter-measure to inappropriate flagging, and indeed my article was vouched for once and was briefly resurrected before it was flagged to death a second time.

Keeping control of an on-line curated forum as it grows is still an unsolved problem.

Dowwie• 10 years ago

TL;DR: "they're asking the public to grant them significant new powers that could put all of our communications infrastructure at risk, and to trust them to not misuse these powers. But they're deliberately misleading the public (and the judiciary) to try to gain these powers. This is not how a trustworthy agency operates. We should not be fooled."

unfamiliar• 10 years ago

The TL;DR should be "iPhone 5C NAND flash can be wiped and restored to default, making brute forcing the PIN a possibility," not this speculative snippet.

vermilingua• 10 years ago

Except that all the evidence points to this speculative snippet being correct, and is the point of the article. So, your tl;dr is missing the crucial point of the article, that the FBI is making a power gambit through deception.

SocksCanClose• 10 years ago

the most frustrating part of this whole thing is the multi-headed response by various agency chieftains. fbi says one thing. nsa says another. former generals say another.

am i crazy to want the president step up and say: "our position as a government is: x"? there's no/no way this has escaped his notice. isn't that part of the job description of "leader of the free world?"

edraferi2• 10 years ago

The executive branch is a big organization. Each agency has a different mission, culture and authorities (legal powers). The cryptowars are a complex issue, so it makes sense that the agencies have different takes on it.

I agree that thr government should have a unified view on all this. However, it should come from CONGRESS, not the President. This is clearly an area where our democracy needs to make a decision about how we govern ourselves, then enshrine that decision in law, then follow that law.

bertil• 10 years ago

What strikes me as odd in all those analysis is that they all assume that the FBI is not expecting that weakened security will mean that there will be far more difficult to address crime -- i.e. far more on their plate.

timr7• 10 years ago

"The FBI can simply remove this chip from the circuit board (“desolder” it), connect it to a device capable of reading and writing NAND flash, and copy all of its data. It can then replace the chip, and start testing passcodes. If it turns out that the auto-erase feature is on, and the Effaceable Storage gets erased, they can remove the chip, copy the original information back in, and replace it. If they plan to do this many times, they can attach a “test socket” to the circuit board that makes it easy and fast to do this kind of chip swapping."

Right. They could do this, and risk destroying the device, or they could ask Apple to do the easy, reliable thing, and just install a build on this phone that allows brute-force attacks.

Given that Apple has a long history of complying with these kinds of requests for valid search warrants, and that this situation is about as clear as it gets when it comes to justifiable uses of government investigatory powers, it's obvious why they're taking the latter approach, and not the former.

There's a legitimate privacy debate in this case, but this isn't it.

Edit: I'm just stating facts here, folks. Downvoting me won't change those facts, or make the government change its tactic.

facetube4• 10 years ago

When has Apple complied with a warrant that sought to compel a digital signature?

timr7• 10 years ago

They're not being asked to provide "a digital signature". They're being asked to enable a brute-force attack on a single phone. Here's the full text of the request:

http://www.ndaa.org/pdf/SB-Shooter-Order-Compelling-Apple-As...

Order #2 is the relevant order. But to answer your question, they've complied with similar warrants on at least 70 cases in the past:

http://www.npr.org/2016/02/22/467602161/the-seeds-of-apples-...

The only difference in this case is whether or not the FBI can compel Apple to make and install a custom build of iOS to crack the phone.

052• 10 years ago

The risk is really negligible if they try practicing on other phones first and use a proper lab.

differentView• 10 years ago

Why the FBI can easily work around “auto-erase”

If it's so easy, then the ACLU should have no problem demonstrating it with an actual iPhone 5c.

Spooky232• 10 years ago

I think this makes the FBI look dumb, but I don't think this really helps them either.

If the NSA did this for espionage it's one thing, but I'm curious as to whether substantially modifying the iPhone in this way would stand up in court.... How would the police assert that they preserved evidence after doing this?

I was involved in a drawn out case challenged the validity of data recovered from backup at great. That was easy to assert with normal IT people, and yet it took weeks to litigate. Couldn't imagine how this would go.

boosting6889• 10 years ago

They're not looking to prosecute anyone (defendant is dead), presumably they're trying to recover info the could lead to more terrorists/plots

Spooky232• 10 years ago

The whole point is to build a precedent, remember?

lswainemoore• 10 years ago

Yes, but presumably they might want to bring what they find as evidence in such future cases.

andromeduck4• 10 years ago

As if they didn't have enough to convict even he the man wasn't already dead.

sabujp• 10 years ago

so john mcaffee was right?

kevin_thibedeau• 10 years ago

If it turns out that the auto-erase feature is on, and the Effaceable Storage gets erased, they can remove the chip, copy the original information back in, and replace it.

Sounds like a better hack would be to interpose the flash memory interface with a RAM cache that simulates writes without modifying the original flash data. Then they can hammer away at brute forcing it without the delay of reburning the flash.

drivingmenuts• 10 years ago

From the sound of various blogs, articles, etc., it sounding like the FBI doesn't have anyone who has technical expertise in this area (or if they do, those persons are being kept buried). While the court case is important to the FBI (and very wrong to the public), the technical details of breaking into an iPhone should not have been an issue for them.

I'm starting to think no one is driving the clown car in their technical division.

mynameisvlad• 10 years ago

Well, according to the congressional hearing (posted in another comment thread on this post), the FBI has "engaged all parts of the US government" to try and find a solution and came up with none. Which is funny, because the congressman who was questioning Comey proposed essentially the same thing as this article.

baldajan2• 10 years ago

This reminds me of the republican congressman from Cali, Issa, telling the FBI in very technical terms (inserting in between that he could be completely wrong) the exact same thing mentioned in this article. I'm unsure if the author was inspired by congressman Issa or if he came to it by his own accord.

More over, what's more fascinating is, some people may say it's privacy v security and the fight for terror. But what has emerged from the last few weeks is multiple reason why the FBI should not win in court, regardless of your perspective of terror. It's been very clear from day 1 that the intentions of the FBI are vicious and non-genuine, and with every passing day, more people are finding out.

darksim905• 10 years ago

I don't know why this case is getting so much attention when it's readily apparently the FBI could just get everything off the phone with a cellebrite & call it a day.

Aoyagi• 10 years ago

Sorry about the slight OT, but what truth is there in this statement I was presented with?

Even if an iPhone is locked, all of that encrypted data can technically be read easily so long as the phone had at least been unlocked once since the time it was booted up.

Obviously I think it's a nonsense, but I have no way of disproving it (even though the burden of proof is on the claimer, naturally).

Edit: OK I found this http://www.darthnull.org/2014/10/06/ios-encryption so never mind, I guess...

ldom66• 10 years ago

Never attribute to malice that which can be attributed to stupidity. Some engineer probably told upper management they couldn't decrypt the phone because the software would erase all data. Maybe because they didn't know, or didn't want to, but still this has blown out of proportion.

To be clear I don't think apple should compromise the phone, just that this is not a long con by the FBI to compromise all phones.

oldmanjay2• 10 years ago

There needs to be a corollary considered here, possibly something like "never invoke the stupidity out lane for those who have previously demonstrated their malice"

zaroth2• 10 years ago

Relevant grant from the Department of Homeland Security from 2011: https://www.sbir.gov/sbirsearch/detail/361729

I'm surprised someone at Uni hasn't made demonstrating this exact attack a class project.

One of the FBI’s Major Claims in the iPhone Case Is Fraudulent

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