Entries Tagged "academic papers"

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Stabbing People with Stuff You Can Get Through Airport Security

Use of a pig model to demonstrate vulnerability of major neck vessels to inflicted trauma from common household items,” from the American Journal of Forensic Medical Pathology.

Abstract. Commonly available items including a ball point pen, a plastic knife, a broken wine bottle, and a broken wine glass were used to inflict stab and incised wounds to the necks of 3 previously euthanized Large White pigs. With relative ease, these items could be inserted into the necks of the pigs next to the jugular veins and carotid arteries. Despite precautions against the carrying of metal objects such as knives and nail files on board domestic and international flights, objects are still available within aircraft cabins that could be used to inflict serious and potentially life-threatening injuries. If airport and aircraft security measures are to be consistently applied, then consideration should be given to removing items such as glass bottles and glass drinking vessels. However, given the results of a relatively uncomplicated modification of a plastic knife, it may not be possible to remove all dangerous objects from aircraft. Security systems may therefore need to focus on measures such as increased surveillance of passenger behavior, rather than on attempting to eliminate every object that may serve as a potential weapon.

Posted on November 19, 2009 at 7:10 AMView Comments

How Smart are Islamic Terrorists?

Organizational Learning and Islamic Militancy (May 2009) was written by Michael Kenney for the U.S. Department of Justice. It’s long: 146 pages. From the executive summary:

Organizational Learning and Islamic Militancy contains significant findings for counter-terrorism research and policy. Unlike existing studies, this report suggests that the relevant distinction in knowledge learned by terrorists is not between tacit and explicit knowledge, but metis and techne. Focusing on the latter sheds new insight into how terrorists acquire the experiential “know how” they need to perform their activities as opposed to abstract “know what” contained in technical bomb-making preparations. Drawing on interviews with bomb-making experts and government intelligence officials, the PI illustrates the critical difference between learning terrorism skills such as bomb-making and weapons firing by abstraction rather than by doing. Only the latter provides militants with the experiential, intuitive knowledge, in other words the metis, they need to actually build bombs, fire weapons, survey potential targets, and perform other terrorism-related activities. In making this case, the PI debunks current misconceptions regarding the Internet’s perceived role as a source of terrorism knowledge.

Another major research finding of this study is that while some Islamic militants learn, they do not learn particularly well. Much terrorism learning involves fairly routine adaptations in communications practices and targeting tactics, what organization theorists call single-loop learning or adaptation. Less common among militants are consequential changes in beliefs and values that underlie collection action or even changes in organizational goals and strategies. Even when it comes to single-loop learning, Islamic militants face significant impediments. Many terrorist conspiracies are compartmented, which makes learning difficult by impeding the free flow of information between different parts of the enterprise. Other, non-compartmented conspiracies are hindered from learning because the same people that survey targets and build bombs also carry out the attacks. Still other operations, including relatively successful ones like the Madrid bombings in 2004, are characterized by such sloppy tradecraft that investigators piece together the conspiracy quickly, preventing additional attacks and limiting militants’ ability to learn from experience.

Indeed, one of the most significant findings to emerge from this research regards the poor tradecraft and operational mistakes repeatedly committed by Islamic terrorists. Even the most “successful” operations in recent years—9/11, 3/11, and 7/7—contained basic errors in tradecraft and execution. The perpetrators that carried out these attacks were determined, adaptable (if only in a limited, tactical sense)—and surprisingly careless. The PI extracts insights from his informants that help account for terrorists’ poor tradecraft: metis in guerrilla warfare that does not translate well to urban terrorism, the difficulty of acquiring mission-critical experience when the attack or counter-terrorism response kills the perpetrators, a hostile counter-terrorism environment that makes it hard to plan and coordinate attacks or develop adequate training facilities, and perpetrators’ conviction that they don’t need to be too careful when carrying out attacks because their fate has been predetermined by Allah. The PI concludes this report by discussing some of the policy implications of these findings, suggesting that the real threat from Islamic militancy comes less from hyper-sophisticated “super terrorists” than from steadfast militants whose own dedication to the cause may undermine the cunning intelligence and fluid adaptability they need to survive.

Posted on November 18, 2009 at 1:45 PMView Comments

Quantum Ghost Imaging

This is cool:

Ghost imaging is a technique that allows a high-resolution camera to produce an image of an object that the camera itself cannot see. It uses two sensors: one that looks at a light source and another that looks at the object. These sensors point in different directions. For example, the camera can face the sun and the light meter can face an object.

That object might be a soldier, a tank or an airplane, Ron Meyers, a laboratory quantum physicist explained during an Oct. 28 interview on the Pentagon Channel podcast “Armed with Science: Research and Applications for the Modern Military.”

Once this is done, a computer program compares and combines the patterns received from the object and the light. This creates a “ghost image,” a black-and-white or color picture of the object being photographed. The earliest ghost images were silhouettes, but current ones depict the objects more realistically.

[…]

Using virtually any light source—from a fluorescent bulb, lasers, or even the sun—quantum ghost imaging gives a clearer picture of objects by eliminating conditions such as clouds, fog and smoke beyond the ability of conventional imaging.

EDITED TO ADD (12/12): A better explanation of the effect, and a detailed paper.

Posted on November 18, 2009 at 6:22 AMView Comments

A Useful Side-Effect of Misplaced Fear

A study in the British Journal of Criminology makes the point that drink-spiking date-raping is basically an urban legend:

Abstract. There is a stark contrast between heightened perceptions of risk associated with drug-facilitated sexual assault (DFSA) and a lack of evidence that this is a widespread threat. Through surveys and interviews with university students in the United Kingdom and United States, we explore knowledge and beliefs about drink-spiking and the linked threat of sexual assault. University students in both locations are not only widely sensitized to the issue, but substantial segments claim first- or second-hand experience of particular incidents. We explore students’ understanding of the DFSA threat in relationship to their attitudes concerning alcohol, binge-drinking, and responsibility for personal safety. We suggest that the drink-spiking narrative has a functional appeal in relation to the contemporary experience of young women’s public drinking.

In an article on the study in The Telegraph, the authors said:

Among young people, drink spiking stories have attractive features that could “help explain” their disproportionate loss of control after drinking alcohol, the study found.

Dr Burgess said: “Our findings suggest guarding against drink spiking has also become a way for women to negotiate how to watch out for each other in an environment where they might well lose control from alcohol consumption.”

[…]

“As Dr Burgess observes, it is not scientific evidence which keeps the drug rape myth alive but the fact that it serves so many useful functions.”

Basically, the hypothesis is that perpetuating the fear of drug-rape allows parents and friends to warn young women off excessive drinking without criticizing their personal choices. The fake bogeyman lets people avoid talking about the real issues.

Posted on November 17, 2009 at 5:58 AMView Comments

Protecting OSs from RootKits

Interesting research: “Countering Kernel Rootkits with Lightweight Hook Protection,” by Zhi Wang, Xuxian Jiang, Weidong Cui, and Peng Ning.

Abstract: Kernel rootkits have posed serious security threats due to their stealthy manner. To hide their presence and activities, many rootkits hijack control flows by modifying control data or hooks in the kernel space. A critical step towards eliminating rootkits is to protect such hooks from being hijacked. However, it remains a challenge because there exist a large number of widely-scattered kernel hooks and many of them could be dynamically allocated from kernel heap and co-located together with other kernel data. In addition, there is a lack of flexible commodity hardware support, leading to the socalled protection granularity gap ­ kernel hook protection requires byte-level granularity but commodity hardware only provides pagelevel protection.

To address the above challenges, in this paper, we present HookSafe, a hypervisor-based lightweight system that can protect thousands of kernel hooks in a guest OS from being hijacked. One key observation behind our approach is that a kernel hook, once initialized, may be frequently “read”-accessed, but rarely “write”-accessed. As such, we can relocate those kernel hooks to a dedicated page-aligned memory space and then regulate accesses to them with hardware-based page-level protection. We have developed a prototype of HookSafe and used it to protect more than 5, 900 kernel hooks in a Linux guest. Our experiments with nine real-world rootkits show that HookSafe can effectively defeat their attempts to hijack kernel hooks. We also show that HookSafe achieves such a large-scale protection with a small overhead (e.g., around 6% slowdown in performance benchmarks).

The research will be presented at the 16th ACM Conference on Computer and Communications Security this week. Here’s an article on the research.

Posted on November 10, 2009 at 1:26 PMView Comments

Laissez-Faire Access Control

Recently I wrote about the difficulty of making role-based access control work, and how reasearch at Dartmouth showed that it was better to let people take the access control they need to do their jobs, and audit the results. This interesting paper, “Laissez-Faire File Sharing,” tries to formalize the sort of access control.

Abstract: When organizations deploy file systems with access control mechanisms that prevent users from reliably sharing files with others, these users will inevitably find alternative means to share. Alas, these alternatives rarely provide the same level of confidentiality, integrity, or auditability provided by the prescribed file systems. Thus, the imposition of restrictive mechanisms and policies by system designers and administrators may actually reduce the system’s security.

We observe that the failure modes of file systems that enforce centrally-imposed access control policies are similar to the failure modes of centrally-planned economies: individuals either learn to circumvent these restrictions as matters of necessity or desert the system entirely, subverting the goals behind the central policy.

We formalize requirements for laissez-faire sharing, which parallel the requirements of free market economies, to better address the file sharing needs of information workers. Because individuals are less likely to feel compelled to circumvent systems that meet these laissez-faire requirements, such systems have the potential to increase both productivity and security.

Think of Wikipedia as the ultimate example of this. Everybody has access to everything, but there are audit mechanisms in place to prevent abuse.

Posted on November 9, 2009 at 6:59 AMView Comments

The Problems with Unscientific Security

From the Open Access Journal of Forensic Psychology, by a whole list of authors: “A Call for Evidence-Based Security Tools“:

Abstract: Since the 2001 attacks on the twin towers, policies on security have changed drastically, bringing about an increased need for tools that allow for the detection of deception. Many of the solutions offered today, however, lack scientific underpinning.

We recommend two important changes to improve the (cost) effectiveness of security policy. To begin with, the emphasis of deception research should shift from technological to behavioural sciences. Secondly, the burden of proof should lie with the manufacturers of the security tools. Governments should not rely on security tools that have not passed scientific scrutiny, and should only employ those methods that have been proven effective. After all, the use of tools that do not work will only get us further from the truth.

One excerpt:

In absence of systematic research, users will base their evaluation on data generated by field use. Because people tend to follow heuristics rather than the rules of probability theory, perceived effectiveness can substantially differ from true effectiveness (Tversky & Kahneman, 1973). For example, one well-known problem associated with field studies is that of selective feedback. Investigative authorities are unlikely to receive feedback from liars who are erroneously considered truthful. They will occasionally receive feedback when correctly detecting deception, for example through confessions (Patrick & Iacono, 1991; Vrij, 2008). The perceived effectiveness that follows from this can be further reinforced through confirmation bias: Evidence confirming one’s preconception is weighted more heavily than evidence contradicting it (Lord, Ross, & Lepper, 1979). As a result, even techniques that perform at chance level may be perceived as highly effective (Iacono, 1991). This unwarranted confidence can have profound effects on citizens’ safety and civil liberty: Criminals may escape detection while innocents may be falsely accused. The Innocence Project (Unvalidated or improper science, no date) demonstrates that unvalidated or improper forensic science can indeed lead to wrongful convictions (see also Saks & Koehler, 2005).

Article on the paper.

Posted on November 5, 2009 at 6:11 AMView Comments

Detecting Forged Signatures Using Pen Pressure and Angle

Interesting:

Songhua Xu presented an interesting idea for measuring pen angle and pressure to present beautiful flower-like visual versions of a handwritten signature. You could argue that signatures are already a visual form, nicely identifiable and universal. However, with the added data about pen pressure and angle, the authors were able to create visual signatures that offer potentially greater security, assuming you can learn to read them.

A better image. The paper (abstract is free; paper is behind a paywall).

Posted on October 8, 2009 at 6:43 AMView Comments

Reproducing Keys from Photographs

Reproducing keys from distant and angled photographs:

Abstract:
The access control provided by a physical lock is based on the assumption that the information content of the corresponding key is private—that duplication should require either possession of the key or a priori knowledge of how it was cut. However, the ever-increasing capabilities and prevalence of digital imaging technologies present a fundamental challenge to this privacy assumption. Using modest imaging equipment and standard computer vision algorithms, we demonstrate the effectiveness of physical key teleduplication—extracting a key’s complete and precise bitting code at a distance via optical decoding and then cutting precise duplicates. We describe our prototype system, Sneakey, and evaluate its effectiveness, in both laboratory and real-world settings, using the most popular residential key types in the U.S.

Those of you who carry your keys on a ring dangling from a belt loop, take note.

Posted on October 1, 2009 at 2:09 PMView Comments

Inferring Friendship from Location Data

Interesting:

For nine months, Eagle’s team recorded data from the phones of 94 students and staff at MIT. By using blue-tooth technology and phone masts, they could monitor the movements of the participants, as well as their phone calls. Their main goal with this preliminary study was to compare data collected from the phones with subjective self-report data collected through traditional survey methodology.

The participants were asked to estimate their average spatial proximity to the other participants, whether they were close friends, and to indicate how satisfied they were at work.

Some intriguing findings emerged. For example, the researchers could predict with around 95 per cent accuracy who was friends with whom by looking at how much time participants spent with each other during key periods, such as Saturday nights.

According to the abstract:

Data collected from mobile phones have the potential to provide insight into the relational dynamics of individuals. This paper compares observational data from mobile phones with standard self-report survey data. We find that the information from these two data sources is overlapping but distinct. For example, self-reports of physical proximity deviate from mobile phone records depending on the recency and salience of the interactions. We also demonstrate that it is possible to accurately infer 95% of friendships based on the observational data alone, where friend dyads demonstrate distinctive temporal and spatial patterns in their physical proximity and calling patterns. These behavioral patterns, in turn, allow the prediction of individual-level outcomes such as job satisfaction.

We all leave data shadows everywhere we go, and maintaining privacy is very hard. Here’s the EFF writing about locational privacy.

EDITED TO ADD (10/12): More information.

Posted on September 21, 2009 at 1:41 PMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.