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Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

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Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#91

Post by X-Istence »

superuser2 wrote: post #78
X-Istence wrote: post #56

Earlier quoted context omitted.

If you can break AES... then the NSA would love to have a word with you :P The FBI is going after the lowest hanging fruit, the users password that was used to create the crypto key.

The user's password is not used to create the crypto key; it is randomly generated and burned in at the factory.

It is used to create the crypto key, using a password based key derivation function, using the user's password fed into the PBKDF the output is the key used for encryption/decryption.

The users device key is mixed into that PBKDF. Without both parts of the equation, you have nothing.

For your reading enjoyment: https://www.apple.com/business/docs/iOS_Security_Guide.pdf

Specifically page 11 the diagram at the bottom.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#92

Post by sandworm101 »

ggreer wrote: post #13
randyrand wrote: post #12

Earlier quoted context omitted.

Even if touch id, it would be of no use. TouchID requires a password after 48 hours. or after the device resets. Which is interesting. If you happen to use TouchID, is your best bet to hope a court will not be able to compel you to unlock it within 48 hours of arrest? That sounds very probable.

After five failed fingerprint attempts, your password is required to unlock the phone. That seems pretty safe to me. If you're ever ordered to unlock the phone, just touch an unregistered finger to it. Fingerprint sensors aren't foolproof. It'd be hard to prove you deliberately sabotaged the effort. Though, one feature I'd like would be to register a distress fingerprint. Then I could touch say... my left index finge…

They would fingerprint the reader, and you, to get a rough idea of which finger is a likely candidate. Even an extremely partial print should be enough to narrow it down to 4 or 5. The reality is that all right-handed people hold phones in their left and so use fingers on their right hand. Lefties do the reverse. So it is already down to five candidates ... which might have something to do with why apple picked that number in the first place.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#93

Post by Karunamon »

mchahn wrote: post #32

Why can't they just pull the flash memory and work on it directly?

Problem becomes harder. The (comparatively weak) passcode gets run through a large number of hashing rounds, which takes about five seconds of real time to complete. The results of that hash are the actual key to a very strong algorithm.

It makes more sense to try brute forcing the hash, even with the delay time.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#94

Post by radiorental »

dplgk wrote: post #85

The 5th amendment protects evidence inside the brain of the accused. As devices becomes more and more an extension of the brain, the more I think we'll need to adjust the rule of the 5th amendment to cover things outside of the brain.

I'm having trouble correlating the intent of the law with your suggestion

"[No person]…shall be compelled in any criminal case to be a witness against himself"

Person/Compelled is key here, not the facts of the case or where they reside.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#95

Post by vonklaus »

tptacek wrote: post #4

Remember, this is an iPhone 5C, which doesn't have Touch ID or the Secure Enclave; the security model for this phone is significantly different from that of more recent iPhones. On phones with a Secure Enclave, the wipe-on-failures state is managed in the coprocessor (which runs L4), and is not straightforwardly backdoor-able. If you're worried about the police brute-forcing your phone, enable Touch ID and set a pass…

Interesting. Let's take this current tech you described and apply it to this situation, what happens.

You did some unspeakable act and you are dead.

* You have securely enabled touchID

Even if you have 10 tries, barring using random appendages your phone can be unlocked right?

Edit: on my phone so far it is password OR touchID. Making this easily defeatable with the physical device and my:

1. Hand if I am dead or alive.

2. A copy of my fingerprints on file with the gov't (true for me)

3. A non-gov adversary with literally anything i've touched.

Maybe I can enable both, but currently it is either or.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#96

Post by vonklaus »

tptacek wrote: post #4

Remember, this is an iPhone 5C, which doesn't have Touch ID or the Secure Enclave; the security model for this phone is significantly different from that of more recent iPhones. On phones with a Secure Enclave, the wipe-on-failures state is managed in the coprocessor (which runs L4), and is not straightforwardly backdoor-able. If you're worried about the police brute-forcing your phone, enable Touch ID and set a pass…

Interesting. Let's take this current tech you described and apply it to this situation, what happens.

You did some unspeakable act and you are dead.

* You have securely enabled touchID

Even if you have 10 tries, barring using random appendages your phone can be unlocked right?

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#97

Post by stepanhruda »

scottcanoni wrote: post #41
Myrmornis wrote: post #36

Why the worry about auto-wiping? Is it not possible to make a copy of the encrypted data and then play around with it as much as you want?

Can someone answer this? Raw read the memory to an external device and then brute force that shit using super computers until it cries.

Damn, that's a great idea. Talk to you in a billion billion years.

http://www.eetimes.com/document.asp?doc_id=1279619

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#98

Post by Natsu »

ggreer wrote: post #13
randyrand wrote: post #12

Earlier quoted context omitted.

Even if touch id, it would be of no use. TouchID requires a password after 48 hours. or after the device resets. Which is interesting. If you happen to use TouchID, is your best bet to hope a court will not be able to compel you to unlock it within 48 hours of arrest? That sounds very probable.

After five failed fingerprint attempts, your password is required to unlock the phone. That seems pretty safe to me. If you're ever ordered to unlock the phone, just touch an unregistered finger to it. Fingerprint sensors aren't foolproof. It'd be hard to prove you deliberately sabotaged the effort. Though, one feature I'd like would be to register a distress fingerprint. Then I could touch say... my left index finge…

Going through a few thought experiments, one might think they could adapt by dusting it for prints and requiring you to use the one they found there.

On the other hand, one might habitually touch, but not register, random fingers to it, while registering some fairly unusual finger as the real one, while using the dominant hand's index finger to "unlock" it.

Finally, someone might decide that if you fail the unlock, they'll just inspect the fingerprint module in isolation and if it works, they'll assume you did that deliberately.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#99

Post by whatwhatwhat999 »

Unfortunately, there's no good outcome here.

If Apple can unencrypt the phone, it will prove to everyone that backdoors exist. If they can't, and they tell the FBI as much, it will just give politicians more reasons sound off about how we have to have backdoors, because this shooter was a "terrorist" after all, and we just have to suck it up and do whatever is necessary to go after people like that.

Either way, we end up with backdoors.

Re: Apple ordered to bypass auto-erase on San Bernadino shooter's iPhone

#100

Post by X-Istence »

vonklaus wrote: post #95
tptacek wrote: post #4

Remember, this is an iPhone 5C, which doesn't have Touch ID or the Secure Enclave; the security model for this phone is significantly different from that of more recent iPhones. On phones with a Secure Enclave, the wipe-on-failures state is managed in the coprocessor (which runs L4), and is not straightforwardly backdoor-able. If you're worried about the police brute-forcing your phone, enable Touch ID and set a pass…

Interesting. Let's take this current tech you described and apply it to this situation, what happens. You did some unspeakable act and you are dead. * You have securely enabled touchID Even if you have 10 tries, barring using random appendages your phone can be unlocked right? Edit: on my phone so far it is password OR touchID. Making this easily defeatable with the physical device and my: 1. Hand if I am dead or ali…

After 5 tries with your finger, an iPhone will require passcode for any further unlocks.

Also, after 48 hours an iPhone requires a passcode to be unlocked, even if TouchID is enabled.

So you have limited time, and have to hope you guess the right finger to use and it reads the finger within that 5 try period.

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