Entries Tagged "privacy"

Page 137 of 147

Cameras Catch Dry Run of 7/7 London Terrorists

Score one for security cameras:

Newly released CCTV footage shows the 7 July London bombers staged a practice run nine days before the attack.

Detectives reconstructed the bombers’ movements after studying thousands of hours of film as part of the probe into the blasts which killed 52 people.

CCTV images show three of the bombers entering Luton station, before travelling to King’s Cross station where they are also pictured.

Officers are keen to find out if the men met anyone else on the day.

See also The New York Times.

Security cameras certainly aren’t useless. I just don’t think they’re worth it.

Posted on September 21, 2005 at 12:50 PM • View Comments

Privacy Enhanced Computer Display

From the Mitsuibshi Research Laboratories:

The privacy-enhanced computer display uses a ferroelectric shutter glasses and a special device driver to produce a computer display which can be read only by the desired recipient, and not by an onlooker. The display alternately displays the desired information in one field, then the inverse image of the desired information in the next field, at up to 120 Hz refresh. The ferroelectric shutter glasses allow only the desired information to be viewed, while the inverse image causes unauthorized viewers to perceive only a flickering gray image, caused by the persistence of vision in the human visual system. It is also possible to use the system to “underlay” a private message on a public display system.

Posted on September 13, 2005 at 1:22 PM • View Comments

Snooping on Text by Listening to the Keyboard

Fascinating research out of Berkeley. Ed Felten has a good summary:

Li Zhuang, Feng Zhou, and Doug Tygar have an interesting new paper showing that if you have an audio recording of somebody typing on an ordinary computer keyboard for fifteen minutes or so, you can figure out everything they typed. The idea is that different keys tend to make slightly different sounds, and although you don’t know in advance which keys make which sounds, you can use machine learning to figure that out, assuming that the person is mostly typing English text. (Presumably it would work for other languages too.)

Read the rest.

The paper is on the Web. Here’s the abstract:

We examine the problem of keyboard acoustic emanations. We present a novel attack taking as input a 10-minute sound recording of a user typing English text using a keyboard, and then recovering up to 96% of typed characters. There is no need for a labeled training recording. Moreover the recognizer bootstrapped this way can even recognize random text such as passwords: In our experiments, 90% of 5-character random passwords using only letters can be generated in fewer than 20 attempts by an adversary; 80% of 10-character passwords can be generated in fewer than 75 attempts. Our attack uses the statistical constraints of the underlying content, English language, to reconstruct text from sound recordings without any labeled training data. The attack uses a combination of standard machine learning and speech recognition techniques, including cepstrum features, Hidden Markov Models, linear classification, and feedback-based incremental learning.

Posted on September 13, 2005 at 8:13 AM • View Comments

Trusted Computing Best Practices

The Trusted Computing Group (TCG) is an industry consortium that is trying to build more secure computers. They have a lot of members, although the board of directors consists of Microsoft, Sony, AMD, Intel, IBM, SUN, HP, and two smaller companies who are voted on in a rotating basis.

The basic idea is that you build a computer from the ground up securely, with a core hardware “root of trust” called a Trusted Platform Module (TPM). Applications can run securely on the computer, can communicate with other applications and their owners securely, and can be sure that no untrusted applications have access to their data or code.

This sounds great, but it’s a double-edged sword. The same system that prevents worms and viruses from running on your computer might also stop you from using any legitimate software that your hardware or operating system vendor simply doesn’t like. The same system that protects spyware from accessing your data files might also stop you from copying audio and video files. The same system that ensures that all the patches you download are legitimate might also prevent you from, well, doing pretty much anything.

(Ross Anderson has an excellent FAQ on the topic. I wrote about it back when Microsoft called it Palladium.)

In May, the Trusted Computing Group published a best practices document: “Design, Implementation, and Usage Principles for TPM-Based Platforms.” Written for users and implementers of TCG technology, the document tries to draw a line between good uses and bad uses of this technology.

The principles that TCG believes underlie the effective, useful, and acceptable design, implementation, and use of TCG technologies are the following:

  • Security: TCG-enabled components should achieve controlled access to designated critical secured data and should reliably measure and report the system’s security properties. The reporting mechanism should be fully under the owner’s control.
  • Privacy: TCG-enabled components should be designed and implemented with privacy in mind and adhere to the letter and spirit of all relevant guidelines, laws, and regulations. This includes, but is not limited to, the OECD Guidelines, the Fair Information Practices, and the European Union Data Protection Directive (95/46/EC).
  • Interoperability: Implementations and deployments of TCG specifications should facilitate interoperability. Furthermore, implementations and deployments of TCG specifications should not introduce any new interoperability obstacles that are not for the purpose of security.
  • Portability of data: Deployment should support established principles and practices of data ownership.
  • Controllability: Each owner should have effective choice and control over the use and operation of the TCG-enabled capabilities that belong to them; their participation must be opt-in. Subsequently, any user should be able to reliably disable the TCG functionality in a way that does not violate the owner’s policy.
  • Ease-of-use: The nontechnical user should find the TCG-enabled capabilities comprehensible and usable.

It’s basically a good document, although there are some valid criticisms. I like that the document clearly states that coercive use of the technology—forcing people to use digital rights management systems, for example, are inappropriate:

The use of coercion to effectively force the use of the TPM capabilities is not an appropriate use of the TCG technology.

I like that the document tries to protect user privacy:

All implementations of TCG-enabled components should ensure that the TCG technology is not inappropriately used for data aggregation of personal information/

I wish that interoperability were more strongly enforced. The language has too much wiggle room for companies to break interoperability under the guise of security:

Furthermore, implementations and deployments of TCG specifications should not introduce any new interoperability obstacles that are not for the purpose of security.

That sounds good, but what does “security” mean in that context? Security of the user against malicious code? Security of big media against people copying music and videos? Security of software vendors against competition? The big problem with TCG technology is that it can be used to further all three of these “security” goals, and this document is where “security” should be better defined.

Complaints aside, it’s a good document and we should all hope that companies follow it. Compliance is totally voluntary, but it’s the kind of document that governments and large corporations can point to and demand that vendors follow.

But there’s something fishy going on. Microsoft is doing its best to stall the document, and to ensure that it doesn’t apply to Vista (formerly known as Longhorn), Microsoft’s next-generation operating system.

The document was first written in the fall of 2003, and went through the standard review process in early 2004. Microsoft delayed the adoption and publication of the document, demanding more review. Eventually the document was published in June of this year (with a May date on the cover).

Meanwhile, the TCG built a purely software version of the specification: Trusted Network Connect (TNC). Basically, it’s a TCG system without a TPM.

The best practices document doesn’t apply to TNC, because Microsoft (as a member of the TCG board of directors) blocked it. The excuse is that the document hadn’t been written with software-only applications in mind, so it shouldn’t apply to software-only TCG systems.

This is absurd. The document outlines best practices for how the system is used. There’s nothing in it about how the system works internally. There’s nothing unique to hardware-based systems, nothing that would be different for software-only systems. You can go through the document yourself and replace all references to “TPM” or “hardware” with “software” (or, better yet, “hardware or software”) in five minutes. There are about a dozen changes, and none of them make any meaningful difference.

The only reason I can think of for all this Machiavellian maneuvering is that the TCG board of directors is making sure that the document doesn’t apply to Vista. If the document isn’t published until after Vista is released, then obviously it doesn’t apply.

Near as I can tell, no one is following this story. No one is asking why TCG best practices apply to hardware-based systems if they’re writing software-only specifications. No one is asking why the document doesn’t apply to all TCG systems, since it’s obviously written without any particular technology in mind. And no one is asking why the TCG is delaying the adoption of any software best practices.

I believe the reason is Microsoft and Vista, but clearly there’s some investigative reporting to be done.

(A version of this essay previously appeared on CNet’s News.com and ZDNet.)

EDITED TO ADD: This comment completely misses my point. Which is odd; I thought I was pretty clear.

EDITED TO ADD: There is a thread on Slashdot on the topic.

EDITED TO ADD: The Sydney Morning Herald republished this essay. Also “The Age.”

Posted on August 31, 2005 at 8:27 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

Cameras in the New York City Subways

New York City is spending $212 million on surveillance technology: 1,000 video cameras and 3,000 motion sensors for the city’s subways, bridges, and tunnels.

Why? Why, given that cameras didn’t stop the London train bombings? Why, when there is no evidence that cameras are effectice at reducing either terrorism and crime, and every reason to believe that they are ineffective?

One reason is that it’s the “movie plot threat” of the moment. (You can hear the echos of the movie plots when you read the various quotes in the news stories.) The terrorists bombed a subway in London, so we need to defend our subways. The other reason is that New York City officials are erring on the side of caution. If nothing happens, then it was only money. But if something does happen, they won’t keep their jobs unless they can show they did everything possible. And technological solutions just make everyone feel better.

If I had $212 million to spend to defend against terrorism in the U.S., I would not spend it on cameras in the New York City subways. If I had $212 million to defend New York City against terrorism, I would not spend it on cameras in the subways. This is nothing more than security theater against a movie plot threat.

On the plus side, the money will also go for a new radio communications system for subway police, and will enable cell phone service in underground stations, but not tunnels.

Posted on August 24, 2005 at 1:10 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

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Sidebar photo of Bruce Schneier by Joe MacInnis.