Entries Tagged "academic papers"

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New Paper on Digital Intelligence

David Omand—GCHQ director from 1996-1997, and the UK’s security and intelligence coordinator from 2000-2005—has just published a new paper: “Understanding Digital Intelligence and the Norms That Might Govern It.”

Executive Summary: This paper describes the nature of digital intelligence and provides context for the material published as a result of the actions of National Security Agency (NSA) contractor Edward Snowden. Digital intelligence is presented as enabled by the opportunities of global communications and private sector innovation and as growing in response to changing demands from government and law enforcement, in part mediated through legal, parliamentary and executive regulation. A common set of organizational and ethical norms based on human rights considerations are suggested to govern such modern intelligence activity (both domestic and external) using a three-layer model of security activity on the Internet: securing the use of the Internet for everyday economic and social life; the activity of law enforcement—both nationally and through international agreements—attempting to manage criminal threats exploiting the Internet; and the work of secret intelligence and security agencies using the Internet to gain information on their targets, including in support of law enforcement.

I don’t agree with a lot of it, but it’s worth reading.

My favorite Omand quote is this, defending the close partnership between the NSA and GCHQ in 2013: “We have the brains. They have the money. It’s a collaboration that’s worked very well.”

Posted on March 20, 2015 at 1:51 PM • View Comments

Understanding the Organizational Failures of Terrorist Organizations

New research: Max Abrahms and Philip B.K. Potter, “Explaining Terrorism: Leadership Deficits and Militant Group Tactics,” International Organizations.

Abstract: Certain types of militant groups—those suffering from leadership deficits—are more likely to attack civilians. Their leadership deficits exacerbate the principal-agent problem between leaders and foot soldiers, who have stronger incentives to harm civilians. We establish the validity of this proposition with a tripartite research strategy that balances generalizability and identification. First, we demonstrate in a sample of militant organizations operating in the Middle East and North Africa that those lacking centralized leadership are prone to targeting civilians. Second, we show that when the leaderships of militant groups are degraded from drone strikes in the Afghanistan-Pakistan tribal regions, the selectivity of organizational violence plummets. Third, we elucidate the mechanism with a detailed case study of the al-Aqsa Martyrs Brigade, a Palestinian group that turned to terrorism during the Second Intifada because pressure on the leadership allowed low-level members to act on their preexisting incentives to attack civilians. These findings indicate that a lack of principal control is an important, underappreciated cause of militant group violence against civilians.

I have previously blogged Max Abrahms’s work here, here, and here.

Posted on March 19, 2015 at 8:09 AM • View Comments

How We Become Habituated to Security Warnings on Computers

New research: “How Polymorphic Warnings Reduce Habituation in the Brain ­- Insights from an fMRI Study.”

Abstract: Research on security warnings consistently points to habituation as a key reason why users ignore security warnings. However, because habituation as a mental state is difficult to observe, previous research has examined habituation indirectly by observing its influence on security behaviors. This study addresses this gap by using functional magnetic resonance imaging (fMRI) to open the “black box” of the brain to observe habituation as it develops in response to security warnings. Our results show a dramatic drop in the visual processing centers of the brain after only the second exposure to a warning, with further decreases with subsequent exposures. To combat the problem of habituation, we designed a polymorphic warning that changes its appearance. We show in two separate experiments using fMRI and mouse cursor tracking that our polymorphic warning is substantially more resistant to habituation than conventional warnings. Together, our neurophysiological findings illustrate the considerable influence of human biology on users’ habituation to security warnings.

Webpage.

EDITED TO ADD (3/21): News article.

Posted on March 18, 2015 at 6:48 AM • View Comments

Geotagging Twitter Users by Mining Their Social Graphs

New research: Geotagging One Hundred Million Twitter Accounts with Total Variation Minimization,” by Ryan Compton, David Jurgens, and David Allen.

Abstract: Geographically annotated social media is extremely valuable for modern information retrieval. However, when researchers can only access publicly-visible data, one quickly finds that social media users rarely publish location information. In this work, we provide a method which can geolocate the overwhelming majority of active Twitter users, independent of their location sharing preferences, using only publicly-visible Twitter data.

Our method infers an unknown user’s location by examining their friend’s locations. We frame the geotagging problem as an optimization over a social network with a total variation-based objective and provide a scalable and distributed algorithm for its solution. Furthermore, we show how a robust estimate of the geographic dispersion of each user’s ego network can be used as a per-user accuracy measure which is effective at removing outlying errors.

Leave-many-out evaluation shows that our method is able to infer location for 101,846,236 Twitter users at a median error of 6.38 km, allowing us to geotag over 80% of public tweets.

Posted on March 10, 2015 at 6:50 AM • View Comments

The TSA's FAST Personality Screening Program Violates the Fourth Amendment

New law journal article: “A Slow March Towards Thought Crime: How the Department of Homeland Security’s FAST Program Violates the Fourth Amendment,” by Christopher A. Rogers. From the abstract:

FAST is currently designed for deployment at airports, where heightened security threats justify warrantless searches under the administrative search exception to the Fourth Amendment. FAST scans, however, exceed the scope of the administrative search exception. Under this exception, the courts would employ a balancing test, weighing the governmental need for the search versus the invasion of personal privacy of the search, to determine whether FAST scans violate the Fourth Amendment. Although the government has an acute interest in protecting the nation’s air transportation system against terrorism, FAST is not narrowly tailored to that interest because it cannot detect the presence or absence of weapons but instead detects merely a person’s frame of mind. Further, the system is capable of detecting an enormous amount of the scannee’s highly sensitive personal medical information, ranging from detection of arrhythmias and cardiovascular disease, to asthma and respiratory failures, physiological abnormalities, psychiatric conditions, or even a woman’s stage in her ovulation cycle. This personal information warrants heightened protection under the Fourth Amendment. Rather than target all persons who fly on commercial airplanes, the Department of Homeland Security should limit the use of FAST to where it has credible intelligence that a terrorist act may occur and should place those people scanned on prior notice that they will be scanned using FAST.

Posted on March 6, 2015 at 6:28 AM • View Comments

"Surreptitiously Weakening Cryptographic Systems"

New paper: “Surreptitiously Weakening Cryptographic Systems,” by Bruce Schneier, Matthew Fredrikson, Tadayoshi Kohno, and Thomas Ristenpart.

Abstract: Revelations over the past couple of years highlight the importance of understanding malicious and surreptitious weakening of cryptographic systems. We provide an overview of this domain, using a number of historical examples to drive development of a weaknesses taxonomy. This allows comparing different approaches to sabotage. We categorize a broader set of potential avenues for weakening systems using this taxonomy, and discuss what future research is needed to provide sabotage-resilient cryptography.

EDITED TO ADD (3/3): News article.

Posted on February 25, 2015 at 6:09 AM • View Comments

Cell Phones Leak Location Information through Power Usage

New research on tracking the location of smart phone users by monitoring power consumption:

PowerSpy takes advantage of the fact that a phone’s cellular transmissions use more power to reach a given cell tower the farther it travels from that tower, or when obstacles like buildings or mountains block its signal. That correlation between battery use and variables like environmental conditions and cell tower distance is strong enough that momentary power drains like a phone conversation or the use of another power-hungry app can be filtered out, Michalevsky says.

One of the machine-learning tricks the researchers used to detect that “noise” is a focus on longer-term trends in the phone’s power use rather than those than last just a few seconds or minutes. “A sufficiently long power measurement (several minutes) enables the learning algorithm to ‘see’ through the noise,” the researchers write. “We show that measuring the phone’s aggregate power consumption over time completely reveals the phone’s location and movement.”

Even so, PowerSpy has a major limitation: It requires that the snooper pre-measure how a phone’s power use behaves as it travels along defined routes. This means you can’t snoop on a place you or a cohort has never been, as you need to have actually walked or driven along the route your subject’s phone takes in order to draw any location conclusions.

I’m not sure how practical this is, but it’s certainly interesting.

The paper.

Posted on February 23, 2015 at 10:30 AM • View Comments

Tracking Bitcoin Scams

Interesting paper: “There’s No Free Lunch, Even Using Bitcoin: Tracking the Popularity and Profits of Virtual Currency Scams,” by Marie Vasek and Tyler Moore.

Abstract: We present the first empirical analysis of Bitcoin-based scams: operations established with fraudulent intent. By amalgamating reports gathered by
voluntary vigilantes and tracked in online forums, we identify 192 scams and categorize them into four groups: Ponzi schemes, mining scams, scam wallets and fraudulent exchanges. In 21% of the cases, we also found the associated Bitcoin addresses, which enables us to track payments into and out of the scams. We find that at least $11 million has been contributed to the scams from 13 000 distinct victims. Furthermore, we present evidence that the most successful scams depend on large contributions from a very small number of victims. Finally, we discuss ways in which the scams could be countered.

News article.

Posted on February 4, 2015 at 7:02 AM • View Comments

Subconscious Keys

I missed this paper when it was first published in 2012:

“Neuroscience Meets Cryptography: Designing Crypto Primitives Secure Against Rubber Hose Attacks”

Abstract: Cryptographic systems often rely on the secrecy of cryptographic keys given to users. Many schemes, however, cannot resist coercion attacks where the user is forcibly asked by an attacker to reveal the key. These attacks, known as rubber hose cryptanalysis, are often the easiest way to defeat cryptography. We present a defense against coercion attacks using the concept of implicit learning from cognitive psychology. Implicit learning refers to learning of patterns without any conscious knowledge of the learned pattern. We use a carefully crafted computer game to plant a secret password in the participant’s brain without the participant having any conscious knowledge of the trained password. While the planted secret can be used for authentication, the participant cannot be coerced into revealing it since he or she has no conscious knowledge of it. We performed a number of user studies using Amazon’s Mechanical Turk to verify that participants can successfully re-authenticate over time and that they are unable to reconstruct or even recognize short fragments of the planted secret.

Posted on January 28, 2015 at 6:39 AM • View Comments

Defending Against Liar Buyer Fraud

It’s a common fraud on sites like eBay: buyers falsely claim that they never received a purchased item in the mail. Here’s a paper on defending against this fraud through basic psychological security measures. It’s preliminary research, but probably worth experimental research.

We have tested a collection of possible user-interface enhancements aimed at reducing liar buyer fraud. We have found that showing users in the process of filing a dispute that (1) their computer is recognized, and (2) that their location is known dramatically reduces the willingness to file false claims. We believe the reason for the reduction is that the would-be liars can visualize their lack of anonymity at a time when they are deciding whether to perform a fraudulent action. Interestingly, we also showed that users were not affected by knowing that their computer was recognized, but without their location being pin-pointed, or the other way around. We also determined that a reasonably accurate map was necessary—but that an inaccurate map does not seem to increase the willingness to lie.

Posted on January 21, 2015 at 6:31 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.