Entries Tagged "cell phones"

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Missed Cellphone Calls as Bomb Triggers

What is it with this week? I can’t turn around without seeing another dumb movie-plot threat:

A Thai minister has claimed that by returning missed calls on their cell phones people from the Muslim-majority southern provinces could unintentionally trigger bombs set by Islamic militants.

Thai authorities have begun tracing cell phone calls in a bid to track down suspects who use mobiles to detonate bombs across three provinces along the Malaysian border.

But the minister for information and communication warned that militants could try to foil the two-week-old cell phone registry by calling a random number, hanging up and then wiring the handset to a bomb.

If someone returned to the call, the bomb would blow up and authorities would trace the call to an innocent person, Sora-at Klinpratum told reporters.

Posted on November 29, 2005 at 10:01 AM • View Comments

Stride-Based Security

Can a cell phone detect if it is stolen by measuring the gait of the person carrying it?

Researchers at the VTT Technical Research Centre of Finland have developed a prototype of a cell phone that uses motion sensors to record a user’s walking pattern of movement, or gait. The device then periodically checks to see that it is still in the possession of its legitimate owner, by measuring the current stride and comparing it against that stored in its memory.

Clever, as long as you realize that there are going to be a lot of false alarms. This seems okay:

If the phone suspects it has fallen into the wrong hands, it will prompt the user for a password if they attempt to make calls or access its memory.

Posted on November 16, 2005 at 6:26 AM • View Comments

SMS Denial-of-Service Attack

This is a clever piece of research. Turns out you can jam cell phones with SMS messages. Text messages are transmitted on the same channel that is used to set up voice calls, so if you flood the network with one, then the other can’t happen. The researchers believe that sending 165 text messages a second is enough to disrupt all the cell phones in Manhattan.

From the paper:

ABSTRACT: Cellular networks are a critical component of the economic and social infrastructures in which we live. In addition to voice services, these networks deliver alphanumeric text messages to the vast majority of wireless subscribers. To encourage the expansion of this new service, telecommunications companies offer connections between their networks and the Internet. The ramifications of such connections, however, have not been fully recognized. In this paper, we evaluate the security impact of the SMS interface on the availability of the cellular phone network. Specifically, we demonstrate the ability to deny voice service to cities the size of Washington D.C. and Manhattan with little more than a cable modem. Moreover, attacks targeting the entire United States are feasible with resources available to medium-sized zombie networks. This analysis begins with an exploration of the structure of cellular networks. We then characterize network behavior and explore a number of reconnaissance techniques aimed at effectively targeting attacks on these systems. We conclude by discussing countermeasures that mitigate or eliminate the threats introduced by these attacks.

There’s a New York Times article and a thread on Slashdot.

Posted on October 7, 2005 at 7:43 AM • View Comments

Privacy Risks of Used Cell Phones

Ignore the corporate sleaziness by Cingular for the moment—they sold used cell phones meant for charity—and focus on the privacy implications. Cingular didn’t erase any of the personal information on the used phones they sold.

This reminds me of Simson Garfinkel’s analysis of used hard drives. He found that 90% of them contained old data, some of it very private and interesting.

Erasing data is one of the big problems of the information age. We know how to do it, but it takes time and we mostly don’t bother. And sadly, these kinds of privacy violations are more the norm than the exception. I don’t think it will get better unless Cingular becomes liable for violating its customers’ privacy like that.

EDITED TO ADD: I already wrote about the risks of losing small portable devices.

Posted on August 26, 2005 at 2:58 PM • View Comments

Bluetooth Spam

Advertisers are beaming unwanted content to Bluetooth phones at a distance of 100 meters.

Sure, it’s annoying, but worse, there are serious security risks. Don’t believe this:

Furthermore, there is no risk of downloading viruses or other malware to the phone, says O’Regan: “We don’t send applications or executable code.” The system uses the phone’s native download interface so they should be able to see the kind of file they are downloading before accepting it, he adds.

This company might not send executable code, but someone else certainly could. And what percentage of people who use Bluetooth phones can recognize “the kind of file they are downloading”?

We’ve already seen two ways to steal data from Bluetooth devices. And we know that more and more sensitive data is being stored on these small devices, increasing the risk. This is almost certainly another avenue for attack.

Posted on August 23, 2005 at 12:24 PM • View Comments

Automatic Surveillance Via Cell Phone

Your cell phone company knows where you are all the time. (Well, it knows where your phone is whenever it’s on.) Turns out there’s a lot of information to be mined in that data.

Eagle’s Realty Mining project logged 350,000 hours of data over nine months about the location, proximity, activity and communication of volunteers, and was quickly able to guess whether two people were friends or just co-workers….

He and his team were able to create detailed views of life at the Media Lab, by observing how late people stayed at the lab, when they called one another and how much sleep students got.

Given enough data, Eagle’s algorithms were able to predict what people—especially professors and Media Lab employees—would do next and be right up to 85 percent of the time.

This is worrisome from a number of angles: government surveillance, corporate surveillance for marketing purposes, criminal surveillance. I am not mollified by this comment:

People should not be too concerned about the data trails left by their phone, according to Chris Hoofnagle, associate director of the Electronic Privacy Information Center.

“The location data and billing records is protected by statute, and carriers are under a duty of confidentiality to protect it,” Hoofnagle said.

We’re building an infrastructure of surveillance as a side effect of the convenience of carrying our cell phones everywhere.

Posted on July 28, 2005 at 4:09 PM •

Turning Cell Phones off in Tunnels

In response to the London bombings, officials turned off cell phones in tunnels around New York City, in an attempt to thwart bombers who might use cell phones as remote triggering devices. (Phone service has been restored in two of the four tunnels. As far as I know, it is still not available in th other two.)

This is as idiotic as it gets. It’s a perfect example of what I call “movie plot security”: imagining a particular scenario rather than focusing on the broad threats. It’s completely useless if a terrorist uses something other than a cell phone: a kitchen timer, for example. Even worse, it harms security in the general case. Have people forgotten how cell phones saved lives on 9/11? Communications benefits the defenders far more than it benefits the attackers.

Posted on July 19, 2005 at 7:52 AM • View Comments

Security Risks of Airplane WiFi

I’ve already written about the stupidity of worrying about cell phones on airplanes. Now the Department of Homeland Security is worried about broadband Internet.

Federal law enforcement officials, fearful that terrorists will exploit emerging in-flight broadband services to remotely activate bombs or coordinate hijackings, are asking regulators for the power to begin eavesdropping on any passenger’s internet use within 10 minutes of obtaining court authorization.

In joint comments filed with the FCC last Tuesday, the Justice Department, the FBI and the Department of Homeland Security warned that a terrorist could use on-board internet access to communicate with confederates on other planes, on the ground or in different sections of the same plane—all from the comfort of an aisle seat.

“There is a short window of opportunity in which action can be taken to thwart a suicidal terrorist hijacking or remedy other crisis situations on board an aircraft, and law enforcement needs to maximize its ability to respond to these potentially lethal situations,” the filing reads.

Terrorists never use SSH, after all. (I suppose that’s the next thing the DHS is going to try to ban.)

Posted on July 14, 2005 at 12:02 PM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.