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FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

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Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#511

Post by QuiEgo »

coppsilgold wrote: post #425
mmooss wrote: post #282

Don't be idiots. The FBI may say that whether or not they can get in: 1. If they can get in, now people - including high-value targets like journalists - will use bad security. 2. If the FBI (or another agency) has an unknown capability, the FBI must say they can't get in or reveal their capabilities to all adversaries, including to even higher-profile targets such as counter-intelligence targets. Saying nothing also…

I would not recommend that one trust a secure enclave with full disk encryption (FDE). This is what you are doing when your password/PIN/fingerprint can't contain sufficient entropy to derive a secure encryption key. The problem with low entropy security measures arises due to the fact that this low entropy is used to instruct the secure enclave (TEE) to release/use the actual high entropy key. So the key must be sto…

I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works.

I also recommend looking up PUF and how modern systems use it in conjunction with user provided secrets to dervie keys - a password or fingerprint is one of many inputs into a kdf to get the final keys.

The high level idea is that the key that's being used for encryption is derived from a very well randomized and protected device-unique secret setup at manufacturing time. Your password/fingerprint/whatever are just adding a little extra entropy to that already cryptographically sound seed.

Tl;dr this is a well solved problem on modern security designs.

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#512

Post by tkel »

armadyl wrote: post #402
tadzikpk wrote: post #357

Earlier quoted context omitted.

> I'm sad that a lot more people don't know that Signal for Desktop is much, much less secure against adversaries with your laptop Educate us. What makes it less secure?

In addition to what the other person who replied said, ignoring that iOS/Android/iPadOS is far more secure than macOS, laptops have significantly less hardware-based protections than Pixel/Samsung/Apple mobile devices do. So really the only way a laptop in this situation would be truly secure from LEO is if its fully powered off when it’s seized.

ARM/M1 macOS took their hardware platform from iOS. TEE, signed/verified/readonly system files, etc. They are similar in security now.

[1] https://asahilinux.org/docs/platform/security/ [2] https://support.apple.com/guide/security/hardware-security-o... [3] https://eclecticlight.co/2022/01/04/booting-an-m1-mac-from-h...

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#513

Post by coppsilgold »

QuiEgo wrote: post #511
coppsilgold wrote: post #425

Earlier quoted context omitted.

I would not recommend that one trust a secure enclave with full disk encryption (FDE). This is what you are doing when your password/PIN/fingerprint can't contain sufficient entropy to derive a secure encryption key. The problem with low entropy security measures arises due to the fact that this low entropy is used to instruct the secure enclave (TEE) to release/use the actual high entropy key. So the key must be sto…

I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works. I also recommend looking up PUF and how modern systems use it in conjunction with user provided secrets to dervie keys - a password or fingerprint is one of many inputs into a kdf to get the final keys. The high level idea is that the key that's being used for encryption is derived from a very well randomized and pro…

> I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works.

What does this have to with anything? Tweakable block ciphers or XTS which converts a block cipher to be tweakable operate with an actualized key - the entropy has long been turned into a key.

> Your password/fingerprint/whatever are just adding a little extra entropy to that already cryptographically sound seed.

Correct. The "cryptographically sound seed" however is stored inside the secure enclave for anyone with the capability to extract. Which is the issue I referenced.

And if what you add to the KDF is just a minuscule amount of entropy you may as well have added nothing at all - they perform the addition for the subset of users that actually use high entropy passwords and because it can't hurt. I don't think anyone adds fingerprint entropy though.

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#514

Post by QuiEgo »

coppsilgold wrote: post #513
QuiEgo wrote: post #511

Earlier quoted context omitted.

I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works. I also recommend looking up PUF and how modern systems use it in conjunction with user provided secrets to dervie keys - a password or fingerprint is one of many inputs into a kdf to get the final keys. The high level idea is that the key that's being used for encryption is derived from a very well randomized and pro…

> I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works. What does this have to with anything? Tweakable block ciphers or XTS which converts a block cipher to be tweakable operate with an actualized key - the entropy has long been turned into a key. > Your password/fingerprint/whatever are just adding a little extra entropy to that already cryptographically sound seed. C…

> The "cryptographically sound seed" however is stored inside the secure enclave for anyone with the capability to extract.

Sorry, I'm not sure I follow here. Is anyone believed to have the capability to extract keys from the SE?

The secure enclave (or any Root of Trust) do not allow direct access to keys, they keep the keys locked away internally and use them at your request to do crypto operations. You never get direct access to the keys. The keys used are protected by using IVs, tweaks, or similar as inputs during cryptographic operations so that the root keys can not be derived from the ciphertext, even if the plaintext is controlled by an attacker and they have access to both the plaintext and ciphertext.

Is your concern the secure enclave in an iPhone is deflatable, and in such a way as to allow key extraction of device unique seeds it protects?

Do you have any literature or references where this is known to have occurred?

Tone is sometimes hard in text, so I want to be clear, I'm legit asking this, not trying to argue. If there are any known attacks against Apple's SE that allow key extraction, would love to read up on them.

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#515

Post by coppsilgold »

QuiEgo wrote: post #514
coppsilgold wrote: post #513

Earlier quoted context omitted.

> I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works. What does this have to with anything? Tweakable block ciphers or XTS which converts a block cipher to be tweakable operate with an actualized key - the entropy has long been turned into a key. > Your password/fingerprint/whatever are just adding a little extra entropy to that already cryptographically sound seed. C…

> The "cryptographically sound seed" however is stored inside the secure enclave for anyone with the capability to extract. Sorry, I'm not sure I follow here. Is anyone believed to have the capability to extract keys from the SE? The secure enclave (or any Root of Trust) do not allow direct access to keys, they keep the keys locked away internally and use them at your request to do crypto operations. You never get di…

> Is your concern the secure enclave in an iPhone is deflatable, and in such a way as to allow key extraction of device unique seeds it protects?

This is a safe assumption to make as the secret bits are sitting in a static location known to anyone with the design documents. Actually getting to them may of course be very challenging.

> Do you have any literature or references where this is known to have occurred?

I'm not aware of any, which isn't surprising given the enormous resources Apple spent on this technology. Random researchers aren't very likely to succeed.

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#516

Post by [deleted] »

Melatonic wrote: post #477
niemandhier wrote: post #441

Depending on your jurisdiction faceid is safer than fingerprint, because faceid won’t unlock while your eyes are closed. In many European countries forcing your finger on a scanner would be permissible under certain circumstances, forcing your eyes open so far has been deemed unacceptable.

Good to know. You sure about this though ? I swear I've seen people use Face ID on someone who's sleeping

[deleted]

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#517

Post by niemandhier »

Melatonic wrote: post #477
niemandhier wrote: post #441

Depending on your jurisdiction faceid is safer than fingerprint, because faceid won’t unlock while your eyes are closed. In many European countries forcing your finger on a scanner would be permissible under certain circumstances, forcing your eyes open so far has been deemed unacceptable.

Good to know. You sure about this though ? I swear I've seen people use Face ID on someone who's sleeping

The flag is called: “Require Attention for Face ID”

100% sure about the legal situation in Germany.

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#518

Post by JasonADrury »

rtkwe wrote: post #408
JasonADrury wrote: post #345

Earlier quoted context omitted.

You would at the very least make them guess which finger, there's no indication that happened here. The court can compel you to make your fingers available, it can not force you to disclose which finger or the manner in which you touch that finger on the fingerprint sensor. Apple devices allow only limited attempts. If you're not being actively helpful, the investigators may end in a rather awkward position.

I'd be wary of trying this as it reeks of "one neat trick" thinking applied to law based on a small technicality where law is often subject to the spirit instead of strictly hewing to the most favorable interpretation the exact wording for the citizen. The warrant can just state you're required to unlock the system not simply "make your fingers available". It's fun to try to find places where the rules seem to leave…

No, it's literally based on existing boilerplate language that's already commonly associated with these warrants based on previous litigation.

Making your body parts available is not testimonial, answering "Which finger?" undoubtedly is.

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#519

Post by bitexploder »

John23832 wrote: post #165
bitexploder wrote: post #120

Earlier quoted context omitted.

You do not. We have this thing in our constitution called the 5th amendment. You cannot be forced to divulge the contents of your mind, including your pin or passwords. Case law supports this. For US citizens at least. Hopefully the constitution is still worth something.

https://www.bleepingcomputer.com/news/legal/man-who-refused-...

It took 4 years. What is your point?

Re: FBI couldn't get into WaPo reporter's iPhone because Lockdown Mode enabled

#520

Post by notyourwork »

sejje wrote: post #474
direwolf20 wrote: post #454

Earlier quoted context omitted.

When they arrest you, they have physical control of your body. You're in handcuffs. They can put your fingers against the unlock button. You can make a fist, but they can have more strength and leverage to unfist your fist. There's no known technique to force you to input a password.

Are we not talking about a legal difference? That was my reading.

Yes, my statement was related to legal means. I’m not a lawyer.
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