Tag Archives: cell phones

Security Risks of Relying on a Single Smartphone

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/09/security-risks-of-relying-on-a-single-smartphone.html

Isracard used a single cell phone to communicate with credit card clients, and receive documents via WhatsApp. An employee stole the phone. He reformatted the phone and replaced the SIM card, which was oddly the best possible outcome, given the circumstances. Using the data to steal money would have been much worse.

Here’s a link to an archived version.

Commercial Location Data Used to Out Priest

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/07/commercial-location-data-used-to-out-priest.html

A Catholic priest was outed through commercially available surveillance data. Vice has a good analysis:

The news starkly demonstrates not only the inherent power of location data, but how the chance to wield that power has trickled down from corporations and intelligence agencies to essentially any sort of disgruntled, unscrupulous, or dangerous individual. A growing market of data brokers that collect and sell data from countless apps has made it so that anyone with a bit of cash and effort can figure out which phone in a so-called anonymized dataset belongs to a target, and abuse that information.

There is a whole industry devoted to re-identifying anonymized data. This was something that Snowden showed that the NSA could do. Now it’s available to everyone.

Cell Phone Location Privacy

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/01/cell-phone-location-privacy.html

We all know that our cell phones constantly give our location away to our mobile network operators; that’s how they work. A group of researchers has figured out a way to fix that. “Pretty Good Phone Privacy” (PGPP) protects both user identity and user location using the existing cellular networks. It protects users from fake cell phone towers (IMSI-catchers) and surveillance by cell providers.

It’s a clever system. The players are the user, a traditional mobile network operator (MNO) like AT&T or Verizon, and a new mobile virtual network operator (MVNO). MVNOs aren’t new. They’re intermediaries like Cricket and Boost.

Here’s how it works:

  1. One-time setup: The user’s phone gets a new SIM from the MVNO. All MVNO SIMs are identical.
  2. Monthly: The user pays their bill to the MVNO (credit card or otherwise) and the phone gets anonymous authentication (using Chaum blind signatures) tokens for each time slice (e.g., hour) in the coming month.
  3. Ongoing: When the phone talks to a tower (run by the MNO), it sends a token for the current time slice. This is relayed to a MVNO backend server, which checks the Chaum blind signature of the token. If it’s valid, the MVNO tells the MNO that the user is authenticated, and the user receives a temporary random ID and an IP address. (Again, this is now MVNOs like Boost already work.)
  4. On demand: The user uses the phone normally.

The MNO doesn’t have to modify its system in any way. The PGPP MVNO implementation is in software. The user’s traffic is sent to the MVNO gateway and then out onto the Internet, potentially even using a VPN.

All connectivity is data connectivity in cell networks today. The user can choose to be data-only (e.g., use Signal for voice), or use the MVNO or a third party for VoIP service that will look just like normal telephony.

The group prototyped and tested everything with real phones in the lab. Their approach adds essentially zero latency, and doesn’t introduce any new bottlenecks, so it doesn’t have performance/scalability problems like most anonymity networks. The service could handle tens of millions of users on a single server, because it only has to do infrequent authentication, though for resilience you’d probably run more.

The paper is here.

US Schools Are Buying Cell Phone Unlocking Systems

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/12/us-schools-are-buying-cell-phone-unlocking-systems.html

Gizmodo is reporting that schools in the US are buying equipment to unlock cell phones from companies like Cellebrite:

Gizmodo has reviewed similar accounting documents from eight school districts, seven of which are in Texas, showing that administrators paid as much $11,582 for the controversial surveillance technology. Known as mobile device forensic tools (MDFTs), this type of tech is able to siphon text messages, photos, and application data from student’s devices. Together, the districts encompass hundreds of schools, potentially exposing hundreds of thousands of students to invasive cell phone searches.

The eighth district was in Los Angeles.

IMSI-Catchers from Canada

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/imsi-catchers-from-canada.html

Gizmodo is reporting that Harris Corp. is no longer selling Stingray IMSI-catchers (and, presumably, its follow-on models Hailstorm and Crossbow) to local governments:

L3Harris Technologies, formerly known as the Harris Corporation, notified police agencies last year that it planned to discontinue sales of its surveillance boxes at the local level, according to government records. Additionally, the company would no longer offer access to software upgrades or replacement parts, effectively slapping an expiration date on boxes currently in use. Any advancements in cellular technology, such as the rollout of 5G networks in most major U.S. cities, would render them obsolete.

The article goes on to talk about replacement surveillance systems from the Canadian company Octasic.

Octasic’s Nyxcell V800 can target most modern phones while maintaining the ability to capture older GSM devices. Florida’s state police agency described the device, made for in-vehicle use, as capable of targeting eight frequency bands including GSM (2G), CDMA2000 (3G), and LTE (4G).

[…]

A 2018 patent assigned to Octasic claims that Nyxcell forces a connection with nearby mobile devices when its signal is stronger than the nearest legitimate cellular tower. Once connected, Nyxcell prompts devices to divulge information about its signal strength relative to nearby cell towers. These reported signal strengths (intra-frequency measurement reports) are then used to triangulate the position of a phone.

Octasic appears to lean heavily on the work of Indian engineers and scientists overseas. A self-published biography of the company notes that while the company is headquartered in Montreal, it has “R&D facilities in India,” as well as a “worldwide sales support network.” Nyxcell’s website, which is only a single page requesting contact information, does not mention Octasic by name. Gizmodo was, however, able to recover domain records identifying Octasic as the owner.

New Report on Police Decryption Capabilities

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/new-report-on-police-decryption-capabilities.html

There is a new report on police decryption capabilities: specifically, mobile device forensic tools (MDFTs). Short summary: it’s not just the FBI that can do it.

This report documents the widespread adoption of MDFTs by law enforcement in the United States. Based on 110 public records requests to state and local law enforcement agencies across the country, our research documents more than 2,000 agencies that have purchased these tools, in all 50 states and the District of Columbia. We found that state and local law enforcement agencies have performed hundreds of thousands of cellphone extractions since 2015, often without a warrant. To our knowledge, this is the first time that such records have been widely disclosed.

Lots of details in the report. And in this news article:

At least 49 of the 50 largest U.S. police departments have the tools, according to the records, as do the police and sheriffs in small towns and counties across the country, including Buckeye, Ariz.; Shaker Heights, Ohio; and Walla Walla, Wash. And local law enforcement agencies that don’t have such tools can often send a locked phone to a state or federal crime lab that does.

[…]

The tools mostly come from Grayshift, an Atlanta company co-founded by a former Apple engineer, and Cellebrite, an Israeli unit of Japan’s Sun Corporation. Their flagship tools cost roughly $9,000 to $18,000, plus $3,500 to $15,000 in annual licensing fees, according to invoices obtained by Upturn.