Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why can't Apple decrypt your iPhone?

blog.cryptographyengineering.com

Post reply on HN
Print view View original

101–110 of 132 posts

Re: Why can't Apple decrypt your iPhone?

#101

Post by spike021 »

eridius wrote: post #90
jshevek wrote: post #84

Earlier quoted context omitted.

Maybe I don't understand the problem, but it seems to me that it would be very simple for apple to prevent the popup messages at their discretion, since they write and control the software that causes the popup to happen in the first place.

They would have to update the OS on the device first. And that's definitely not something that can be done silently. I'm assuming here that the OS already doesn't have the ability to suppress the popup, and I think that's a safe assumption because Apple doesn't want to have this ability.

Couldn't the change simply be included in one of the regular .x updates? They don't need to mention it in the changelog. It's not something significant enough that people would really notice.

I don't think Apple would want that capability either, but just for argument's sake.

Re: Why can't Apple decrypt your iPhone?

#102

Post by eridius »

spike021 wrote: post #101
eridius wrote: post #90

Earlier quoted context omitted.

They would have to update the OS on the device first. And that's definitely not something that can be done silently. I'm assuming here that the OS already doesn't have the ability to suppress the popup, and I think that's a safe assumption because Apple doesn't want to have this ability.

Couldn't the change simply be included in one of the regular .x updates? They don't need to mention it in the changelog. It's not something significant enough that people would really notice. I don't think Apple would want that capability either, but just for argument's sake.

They could, but that's not something that law enforcement can just ask them to do on the fly.

Re: Why can't Apple decrypt your iPhone?

#103

Post by eridius »

ObviousScience wrote: post #94
eridius wrote: post #90

Earlier quoted context omitted.

They would have to update the OS on the device first. And that's definitely not something that can be done silently. I'm assuming here that the OS already doesn't have the ability to suppress the popup, and I think that's a safe assumption because Apple doesn't want to have this ability.

> And that's definitely not something that can be done silently. Can you link me to a technical analysis about this? It would be one of the few phones where the baseband/SIM couldn't make changes to the system.

iMessage has nothing at all to do with the baseband or SIM. And carriers definitely can't push updates to the OS. Only Apple has the technical capability to produce updates to the OS, if for no other reason than the fact that all OS code must be codesigned with Apple's certificate, and only Apple has the keys. But since the baseband can't update the OS anyway, that's a moot point.

I don't have a link for a technical analysis of this, but I shouldn't need one. It should be self-evident that updating the OS is a process that is very obvious to the user. It's also something that Apple has never done without explicit action by the user to perform such an update. It would in fact be incredibly dangerous to update the OS without explicit action, if for no other reason than the fact that this would not give the user the chance to back up their phone in case something goes wrong.

Re: Why can't Apple decrypt your iPhone?

#104

Post by triski »

The security is based on the premise that Apple is unable to decrypt as they do not keep a record of the devices unique ID that is the base of all the cryptography.

What if that is not true? What if the device has a built-in keylogger to just get all the crypto from the user input? be it a passcode or a fingerprint.

Wouldn´t it be partly better if this were based on a trully public key cryptography with a randomly generated private key generated each time the device is factory reset?

Re: Why can't Apple decrypt your iPhone?

#105

Post by c_c_c »

scintill76 wrote: post #39
opendais wrote: post #30

Earlier quoted context omitted.

The problem is the attack surface for an app on a device vs. in the wild is much, much larger and much, much less secure. Once its on your phone, it can just screenshot things if nothing else.

Android requires root privilege and/or system-level app to take screenshots. iOS is probably similar. I don't think an app could spy like this without user enabling it (which is a valid but separate concern about how knowledgeable the average rooter/jailbreaker is.) [0] http://android.stackexchange.com/questions/10930/why-do-we-n...

Maybe I'm not fully understanding here but the last two phones I've used do not require root or any app to take screenshots. Nexus 5 and Moto X.

Re: Why can't Apple decrypt your iPhone?

#106

Post by derekp7 »

TazeTSchnitzel wrote: post #71
jacquesm wrote: post #47

Earlier quoted context omitted.

It could be an update of an app that runs by default, or an update of a core component of the OS.

No apps "run by default". The OS's core components require user confirmation, as that's just a normal iOS update.

What about when you get a phone call -- the app that pops up the call UI could be updated, pushed, then triggered by calling the phone.

Re: Why can't Apple decrypt your iPhone?

#107

Post by bartman »

scintill76 wrote: post #39
opendais wrote: post #30

Earlier quoted context omitted.

The problem is the attack surface for an app on a device vs. in the wild is much, much larger and much, much less secure. Once its on your phone, it can just screenshot things if nothing else.

Android requires root privilege and/or system-level app to take screenshots. iOS is probably similar. I don't think an app could spy like this without user enabling it (which is a valid but separate concern about how knowledgeable the average rooter/jailbreaker is.) [0] http://android.stackexchange.com/questions/10930/why-do-we-n...

On iOS it's possible to capture the framebuffers of other apps via the IOSurface APIs with an app that's running in the background. These APIs are not documented well, but it's certainly possible.

Re: Why can't Apple decrypt your iPhone?

#108

Post by simonh »

All the criticisms I've yet seen of Apple's iMessage security comes down to "yes it's probably completely locked down now and for all historical messages, but here's this obscure way they could open it up for messages in the future therefore it's not secure".

Well duh! It's their software. Of course they could backdoor it in future, such as if required to by the government. That's true of any software. Apple are asserting that right now there are no such backdoors and iMessages are secure. I've not seen any credible argument that this is not the case other thst "maybe they're lying". Ok. What's the alternative? Run everything through OpenSSL? That didn't worm out do well. Maybe we should run everything on Linux using Bash scripts. Oops again!

Maybe Apple are lying. Maybe they will sell us all out. But if they do these things always have a tendency to come out in the open eventually. So far they've had a pretty good track record of being on the level. In the end it's tfag reputation, and their appreciation of its value, that is the best and really the only guarantee we have, as with anyone else we rely on.

Re: Why can't Apple decrypt your iPhone?

#109

Post by bryanlarsen »

adsr wrote: post #50
bryanlarsen wrote: post #45

Earlier quoted context omitted.

That's pretty much exactly how AMD implements TrustZone. http://www.anandtech.com/show/6007/amd-2013-apus-to-include-...

It sounds more like they are using a Cortex-A5 to gain access to TrustZone with an existing x86 core.

And it sounds like Apple is using a separate unspecified ARM processor (probably a Cortex-A5 since that's the cheapest possible one) to gain access to an existing A7 or A8 core.

Re: Why can't Apple decrypt your iPhone?

#110

Post by shawnz »

eridius wrote: post #90
jshevek wrote: post #84

Earlier quoted context omitted.

Maybe I don't understand the problem, but it seems to me that it would be very simple for apple to prevent the popup messages at their discretion, since they write and control the software that causes the popup to happen in the first place.

They would have to update the OS on the device first. And that's definitely not something that can be done silently. I'm assuming here that the OS already doesn't have the ability to suppress the popup, and I think that's a safe assumption because Apple doesn't want to have this ability.

> that's definitely not something that can be done silently.

I hate to sound so paranoid, but what reason do you have to believe this?

Post reply on HN