Good essay on the inherent vulnerabilities in the cell phone standards and the market barriers to fixing them.
So far, industry and policymakers have largely dragged their feet when it comes to blocking cell-site simulators and SS7 attacks. Senator Ron Wyden, one of the few lawmakers vocal about this issue, sent a letter in August encouraging the Department of Justice to "be forthright with federal courts about the disruptive nature of cell-site simulators." No response has ever been published.
The lack of action could be because it is a big task -- there are hundreds of companies and international bodies involved in the cellular network. The other reason could be that intelligence and law enforcement agencies have a vested interest in exploiting these same vulnerabilities. But law enforcement has other effective tools that are unavailable to criminals and spies. For example, the police can work directly with phone companies, serving warrants and Title III wiretap orders. In the end, eliminating these vulnerabilities is just as valuable for law enforcement as it is for everyone else.
As it stands, there is no government agency that has the power, funding and mission to fix the problems. Large companies such as AT&T, Verizon, Google and Apple have not been public about their efforts, if any exist.
Abstract: We report the first active acoustic side-channel attack. Speakers are used to emit human inaudible acoustic signals and the echo is recorded via microphones, turning the acoustic system of a smart phone into a sonar system. The echo signal can be used to profile user interaction with the device. For example, a victim's finger movements can be inferred to steal Android phone unlock patterns. In our empirical study, the number of candidate unlock patterns that an attacker must try to authenticate herself to a Samsung S4 Android phone can be reduced by up to 70% using this novel acoustic side-channel. Our approach can be easily applied to other application scenarios and device types. Overall, our work highlights a new family of security threats.
Recently, Apple introduced restricted mode to protect iPhones from attacks by companies like Cellebrite and Greyshift, which allow attackers to recover information from a phone without the password or fingerprint. Elcomsoft just announced that it can easily bypass it.
There is an important lesson in this: security is hard. Apple Computer has one of the best security teams on the planet. This feature was not tossed out in a day; it was designed and implemented with a lot of thought and care. If this team could make a mistake like this, imagine how bad a security feature is when implemented by a team without this kind of expertise.
This is the reason actual cryptographers and security engineers are very skeptical when a random company announces that their product is "secure." We know that they don't have the requisite security expertise to design and implement security properly. We know they didn't take the time and care. We know that their engineers think they understand security, and designed to a level that they couldn't break.
Getting security right is hard for the best teams on the world. It's impossible for average teams.
Interestingresearch in using traffic analysis to learn things about encrypted traffic. It's hard to know how critical these vulnerabilities are. They're very hard to close without wasting a huge amount of bandwidth.
The New York Times is reporting about a company called Securus Technologies that gives police the ability to track cell phone locations without a warrant:
The service can find the whereabouts of almost any cellphone in the country within seconds. It does this by going through a system typically used by marketers and other companies to get location data from major cellphone carriers, including AT&T, Sprint, T-Mobile and Verizon, documents show.
Some details about the iPhone unlocker from the US company Greyshift, with photos.
Little is known about Grayshift or its sales model at this point. We don't know whether sales are limited to US law enforcement, or if it is also selling in other parts of the world. Regardless of that, it's highly likely that these devices will ultimately end up in the hands of agents of an oppressive regime, whether directly from Grayshift or indirectly through the black market.
It's also entirely possible, based on the history of the IP-Box, that Grayshift devices will end up being available to anyone who wants them and can find a way to purchase them, perhaps by being reverse-engineered and reproduced by an enterprising hacker, then sold for a couple hundred bucks on eBay.
Forbesreports that the Israeli company Cellebrite can probably unlock all iPhone models:
Cellebrite, a Petah Tikva, Israel-based vendor that's become the U.S. government's company of choice when it comes to unlocking mobile devices, is this month telling customers its engineers currently have the ability to get around the security of devices running iOS 11. That includes the iPhone X, a model that Forbes has learned was successfully raided for data by the Department for Homeland Security back in November 2017, most likely with Cellebrite technology.
It also appears the feds have already tried out Cellebrite tech on the most recent Apple handset, the iPhone X. That's according to a warrant unearthed by Forbes in Michigan, marking the first known government inspection of the bleeding edge smartphone in a criminal investigation. The warrant detailed a probe into Abdulmajid Saidi, a suspect in an arms trafficking case, whose iPhone X was taken from him as he was about to leave America for Beirut, Lebanon, on November 20. The device was sent to a Cellebrite specialist at the DHS Homeland Security Investigations Grand Rapids labs and the data extracted on December 5.
This story is based on some excellent reporting, but leaves a lot of questions unanswered. We don't know exactly what was extracted from any of the phones. Was it metadata or data, and what kind of metadata or data was it.
The story I hear is that Cellebrite hires ex-Apple engineers and moves them to countries where Apple can't prosecute them under the DMCA or its equivalents. There's also a credible rumor that Cellebrite's mechanisms only defeat the mechanism that limits the number of password attempts. It does not allow engineers to move the encrypted data off the phone and run an offline password cracker. If this is true, then strong passwords are still secure.
EDITED TO ADD (3/1): Another article, with more information. It looks like there's an arms race going on between Apple and Cellebrite. At least, if Cellebrite is telling the truth -- which they may or may not be.
The cell phones we carry with us constantly are the most perfect surveillance device ever invented, and our laws haven't caught up to that reality. That might change soon.
This week, the Supreme Court will hear a case with profound implications for your security and privacy in the coming years. The Fourth Amendment's prohibition of unlawful search and seizure is a vital right that protects us all from police overreach, and the way the courts interpret it is increasingly nonsensical in our computerized and networked world. The Supreme Court can either update current law to reflect the world, or it can further solidify an unnecessary and dangerous police power.
The case centers on cell phone location data and whether the police need a warrant to get it, or if they can use a simple subpoena, which is easier to obtain. Current Fourth Amendment doctrine holds that you lose all privacy protections over any data you willingly share with a third party. Your cellular provider, under this interpretation, is a third party with whom you've willingly shared your movements, 24 hours a day, going back months -- even though you don't really have any choice about whether to share with them. So police can request records of where you've been from cell carriers without any judicial oversight. The case before the court, Carpenter v. United States, could change that.
Traditionally, information that was most precious to us was physically close to us. It was on our bodies, in our homes and offices, in our cars. Because of that, the courts gave that information extra protections. Information that we stored far away from us, or gave to other people, afforded fewer protections. Police searches have been governed by the "third-party doctrine," which explicitly says that information we share with others is not considered private.
The Internet has turned that thinking upside-down. Our cell phones know who we talk to and, if we're talking via text or e-mail, what we say. They track our location constantly, so they know where we live and work. Because they're the first and last thing we check every day, they know when we go to sleep and when we wake up. Because everyone has one, they know whom we sleep with. And because of how those phones work, all that information is naturally shared with third parties.
More generally, all our data is literally stored on computers belonging to other people. It's our e-mail, text messages, photos, Google docs, and more all in the cloud. We store it there not because it's unimportant, but precisely because it is important. And as the Internet of Things computerizes the rest our lives, even more data will be collected by other people: data from our health trackers and medical devices, data from our home sensors and appliances, data from Internet-connected "listeners" like Alexa, Siri, and your voice-activated television.
All this data will be collected and saved by third parties, sometimes for years. The result is a detailed dossier of your activities more complete than any private investigator -- or police officer -- could possibly collect by following you around.
The issue here is not whether the police should be allowed to use that data to help solve crimes. Of course they should. The issue is whether that information should be protected by the warrant process that requires the police to have probable cause to investigate you and get approval by a court.
Warrants are a security mechanism. They prevent the police from abusing their authority to investigate someone they have no reason to suspect of a crime. They prevent the police from going on "fishing expeditions." They protect our rights and liberties, even as we willingly give up our privacy to the legitimate needs of law enforcement.
The third-party doctrine never made a lot of sense. Just because I share an intimate secret with my spouse, friend, or doctor doesn't mean that I no longer consider it private. It makes even less sense in today's hyper-connected world. It's long past time the Supreme Court recognized that a months-long history of my movements is private, and my e-mails and other personal data deserve the same protections, whether they're on my laptop or on Google's servers.
On Friday, Vietnamese security firm Bkav released a blog post and video showing that -- by all appearances -- they'd cracked FaceID with a composite mask of 3-D-printed plastic, silicone, makeup, and simple paper cutouts, which in combination tricked an iPhone X into unlocking.
The article points out that the hack hasn't been independently confirmed, but I have no doubt it's true.
I don't think this is cause for alarm, though. Authentication will always be a trade-off between security and convenience. FaceID is another biometric option, and a good one. I wouldn't be less likely to use it because of this.