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Evidence that the FBI can hack into private Signal messages on a locked iPhone

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Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#201

Post by icelancer »

sneak wrote: post #129
kart23 wrote: post #124

After 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?

I 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.

Yeah, 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.

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#202

Post by pokoleo »

TwoBit wrote: post #192
kerng wrote: post #28

Earlier quoted context omitted.

Yes, nothing special - if someone else has your phone, it's not your phone anymore.

Does Signal not encrypt its DBs when not in use and upon shutdown? Edit: it seems that Signal uses db protection but in a way that fails for a cracked phone like this (?): https://news.ycombinator.com/item?id=26096778

Generally: If someone has physical access to a device, you can probably assume they control it.

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#203

Post by anonisko »

brandmeyer wrote: post #20

Universal 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.

The point of encryption and privacy software isn't to make it completely impossible to violate someone's privacy. We still have laws that most of us agree with and want to see them enforced.

The point is to make it impossible to compromise everyone all at once and stream that data into a system designed to automate the manufacturing of consent.

It has to cost something non negligible to violate someone's privacy, and that cost will demand evidence and accountability from those who are authorized to wield that power.

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#204

Post by phnofive »

sneak wrote: post #182
gen3 wrote: post #179

Earlier quoted context omitted.

You can also disable biometrics by spamming the lock button.

On the latest iOS, on the latest/largest iPhone, this does not appear to be true any longer.

It does; five rapid clicks to the side button will trigger an alarm and require a passcode to unlock.

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#205

Post by dredmorbius »

hnrodey wrote: post #26
deanclatworthy wrote: post #22

Why 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.

Criminals are quite often not the sharpest tools in the shed. Expiring messages, staying up on the latest hardware, etc.

Criminals who get caught, one should note.

Sort of a reverse survivorship bias at play here.

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#206

Post by IgorBog61650384 »

xoa wrote: post #83
sprayk wrote: post #55

Earlier quoted context omitted.

Why 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/ [1] https://i.blackhat.com/us-1…

> 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 cus…

Exploits 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?

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#208

Post by tptacek »

bigiain wrote: post #154
tptacek wrote: post #94

Earlier quoted context omitted.

There are plenty of prominent people in software security that have IC backgrounds.

I’ll bet their prominence is fairly carefully vetted, and probably part of their job description rather than the more typical tech industry “personal brand building”. But then that’s evidently true of Google (and FAANG in general) as well.

I'll bet pretty much nobody cares, inside or outside of the IC. It's a fun thing for people to joke about (they've been joking about Aitel for decades) but reality is mostly boring.

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#209

Post by bigiain »

upofadown wrote: post #170
bigiain wrote: post #166

Earlier quoted context omitted.

You 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?…

Fair enough, but my point still remains. You need the key material any time the phone is unlocked. Because we are doing instant messaging that is going to be a lot more exposure time than with some sort of offline system.

You should be able to lock that down to “only while the messaging app is in the foreground”, which limits the exposure time further, but certainly not to zero.

Hopefully, if you care about this, you use and app which can be configured to have its own passphrase/pin which hopefully is used to access properly secured keys from the Secure Enclave only when that’s entered. (Signals interface works like this. I’m only assuming/hoping it’s working that way underneath).

Re: Evidence that the FBI can hack into private Signal messages on a locked iPhone

#210

Post by alasdair_ »

HenryBemis wrote: post #115
godelski wrote: post #48

Earlier quoted context omitted.

In 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. Monitori…

Fun fact for the UK: "UK police have a new tactic to circumvent strong iPhone encryption: steal the unlocked phone out of the criminal’s hand" ( https://9to5mac.com/2016/12/05/uk-police-have-a-new-tactic-f... ) I remember reading this a few years back. The title says it all. Why bother cracking codes etc when you can get a judge to sign THAT for you? :) Going through the PDF of the legal document, on page 10, the scr…

This is pretty much how Scott Albrecht of Silk Road was caught. The police caused a distraction the grabbed his unlocked laptop while he was at a cafe.

Of course, maybe bringing an unlocked laptop with details of your drug empire to a cafe wasn’t the best opsec out there.

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