Archive for the 'Research' Category

UVERS Poster

Monday, April 4th, 2011

Congratulations to Yan Huang for winning an Honorable Mention at the University of Virginia Engineering Research Symposium (UVERS) for his poster on privacy-preserving biometric matching.

The poster is here: [PDF (13MB)]

GuardRails at RubyNation

Monday, March 28th, 2011




Jonathan Burket, Patrick Mutchler, Michael Weaver, and Muzzammil Zaveri will present GuardRails: A (Nearly) Painless Solution to Insecure Web Applications at the RubyNation conference in Reston (near Washington, DC), on April 2.

With web applications continuing to grow in popularity and frameworks becoming simpler to use, creating a web application is easier than ever. While building an application may be straightforward, ensuring that it is secure requires both a deep understanding of subtle security vulnerabilities as well as tedious and careful insertion of security checks. We propose GuardRails, an open source source-to-source tool for Ruby on Rails applications that adds extra layers of security to web applications with only minimal effort from the developer. GuardRails works by attaching security policies to the data itself. These policies are automatically enforced throughout the application, without the need for the developer to write large amounts of code. Our system helps prevent against a variety of security vulnerabilities from CrossSite Scripting to faulty access controls without requiring the developer to have a sophisticated knowledge of web security.

Lattice Ciphers for RFID

Friday, February 4th, 2011

Our paper on using lattice ciphers for low-power public-key encryption targeted to RFID tags is now available. Yu Yao will present the paper in Wuxi, China in April.

Yu Yao, Jiawei Huang, Sudhanshu Khanna, abhi shelat, Benton Highsmith Calhoun, John Lach, and David Evans. A Sub-0.5V Lattice-Based Public-Key Encryption Scheme for RFID Platforms in 130nm CMOS. 2011 Workshop on RFID Security (RFIDsec’11 Asia)
Wuxi, China. 6-8 April 2011.

Abstract: Implementing public-key cryptography on passive RFID tags is very challenging due to the limited die size and power available. Typical public-key algorithms require complex logical components such as modular exponentiation in RSA. We demonstrate the feasibility of implementing public-key encryption on low-power, low cost passive RFID tags to large-scale private identification. We use Oded Regev’s Learning-With-Error (LWE) cryptosystem, which is provably secure under the hardness assumption of classic lattice problems. The advantage of using the LWE cryptosystem is its intrinsic computational simplicity (the main operation is modular addition). We leverage the low speed of RFID application by using circuit design with supply voltage close to transistor threshold (Vt) to lower power. This paper presents protocols for using the LWE cipher to provide private identification, evaluates a design for implementing those protocols on passive RFID tags, and reports on simulation experiments that demonstrate the feasibility of this approach.

Full paper (19 pages): [PDF]

Car Immobilizers

Friday, December 24th, 2010

Karsten Nohl is in the news again, this time for demonstrating how bad the proprietary crypto used for car immobilizers is. Here are a few articles:

Karsten presented the technical aspects in a talk at the 8th Embedded Security in Cars conference in Berlin.

Even if car manufacturers get the crypto right, relay attacks pose a serious threat, especially for modern cars that do away with the mechanical key completely. See the upcoming NDSS paper by Aurelien Francillon, Boris Danev, and Srdjan Capkun: Relay Attacks on Passive Keyless Entry and Start Systems in Modern Cars.

Secure Biometrics

Thursday, December 9th, 2010

We’ve released our code and paper on efficient privacy-preserving biometric identification:

Yan Huang (University of Virginia), Lior Malka (Intel/University of Maryland), David Evans (University of Virginia), and Jonathan Katz (University of Maryland). Efficient Privacy-Preserving Biometric Identification. To appear in 18th Network and Distributed System Security Conference (NDSS 2011), 6-9 February 2011. [PDF, 14 pages]

We present an efficient matching protocol that can be used in many privacy-preserving biometric identification systems in the semi-honest setting. Our most general technical contribution is a new backtracking protocol that uses the by-product of evaluating a garbled circuit to enable efficient oblivious information retrieval. We also present a more efficient protocol for computing the Euclidean distances of vectors, and optimized circuits for finding the closest match between a point held by one party and a set of points held by another. We evaluate our protocols by implementing a practical privacy-preserving fingerprint matching system.

Yan will present the paper at NDSS in February. The code for our system is available under the MIT open source license.


flickr cc: didbygraham

GuardRails at OWASP AppSec DC

Tuesday, November 9th, 2010

Jonathan Burket, Patrick Mutchler, Michael Weaver and Muzzammil Zaveri will present GuardRails at AppSec DC on Wednesday, 10 November. The conference is at the Walter E. Washington Convention Center in Washington, DC.

GuardRails is a framework for automating many of the tasks necessary to build a security web application. For more, see the talk abstract: GuardRails: A Nearly Painless Solution to Insecure Web Applications. (and video and slides will appear there soon)

Update 9 December: The slides are here [PDF].

Oakland 2010 Update

Wednesday, December 2nd, 2009

Oakland 2010 submissions closed last week. We received 269 total submissions (of which 30 were Systematization of Knowledge papers). The program should be available by early February, for the conference that will be held May 16-19, 2010 at the Claremont Resort in Berkeley, CA.

Open-Source GSM Hacking

Wednesday, December 2nd, 2009

IEEE Spectrum has an article on Karsten Nohl’s efforts to lead an open-source GSM hacking project: Open-Source Effort to Hack GSM, IEEE Spectrum, 30 November 2009.

If you’re still using a cellphone based on early digital standards, you better be careful what you say. The encryption technology used to prevent eavesdropping in GSM (Global System for Mobile communications), the world’s most widely used cellphone system, has more security holes than Swiss cheese, according to an expert who plans to poke a big hole of his own.

Karsten Nohl, chief research scientist with H4RDW4RE, a Sunnyvale, Calif.-based security research firm, is mounting what could be the most ambitious attempt yet to compromise the GSM phone system, which is used by over 3 billion people around the world. Others have cracked the A5/1 encryption technology used in GSM before, but their results have remained secret. However, Nohl, who earned a Ph.D. in computer science at the University of Virginia and is a member of Germany’s Chaos Computer Club (CCC), intends to go one big step further: By the end of the year, he plans to make the keys available to everyone on the Internet.

GSM cracking has a long history, which began in the late 1990s in academic circles and has since sprouted a handful of commercial businesses. Today, these companies legally sell GSM call-interception solutions–which are relatively expensive–mostly to government intelligence agencies. In general, supplying and using this software is illegal in the wider market, but no one can say for certain how many groups have illegally gained access to the technology.

That’s the point Nohl hopes to drive home: The A5/1 algorithm is a broken 64-bit encryption technology, a relic of the Cold War era, when laws prohibited the export of strong encryption technology from the United States. It needs to be replaced–ideally by the much stronger, 128-bit A5/3 system, which is already being used in newer-generation digital cellular systems, such as Universal Mobile Telecommunications System (UMTS). “If you go from the 64 bits of the A5/1 cipher to the 128 bits of A5/3,” says Nohl, cracking requires an amount of memory storage that is beyond what “is available on earth.”

A big problem with plugging the GSM encryption hole, according to the security expert, is that operators are unwilling to admit that a problem even exists. Many want to avoid spending additional money on upgrading aging and amortized GSM infrastructure, he says. The GSM Association, which represents the interests of GSM mobile operators around the world, says only that it is aware of various eavesdropping projects. In the same breath, it points to the complexities of identifying and recording calls from RF signals.

To Facebook or not to Facebook

Saturday, July 4th, 2009

The Examiner has an article on Facebook privacy issues: To Facebook or not to Facebook, 29 June 2009.

The second approach is even scarier, a feature of Facebook which allows outside developers to create small programs called “applications” for members to do things like playing poker, getting daily horoscopes, and sending each other virtual fantasies. With the younger set, the latter must cause parents a lot of consternation over their kids. Word is there are about 24,000 applications that have been built by 400,000 developers.

And here’s the kicker. Once these developers have your personal data, there is nothing Facebook can do. Adrienne Felt of the University of Virginia investigated the procedure in her thesis and found out that 90 out of 150 of Facebook’s most popular applications (that’s 60 percent) have unnecessary access to your private information.

How Facebook Mucks Up Office Life

Saturday, May 2nd, 2009

Jake Widman has written an interesting article about the impact of “oversharing” on Facebook: How Facebook mucks up office life: Managing a workforce is already a challenging job; now Facebook and other social networks raise a host of sticky new situations., ComputerWorld, 30 April 2009.

The key observation is the way social networks mix different social circles that would rarely intersect in real life, along with people’s willingness to accept friend requests from unknown or unvalidated individuals.

Separate from the social challenge is the issue of people, particularly younger Facebook users, becoming friends with people they don’t know well, or even at all. “Facebook doesn’t have our normal social mechanisms for validating someone,” Argast points out — and many users, especially people who use Facebook to network, are reluctant to turn down a friend request.

The article mentions studies that indicate both that a significant fraction (23%) of hiring managers check social networking sites on potential hires, and that the majority of Facebook users do not understand how visible their “private” information is.

The article also highlights the additional risks of applications.

A further issue is the fact Facebook applications gain access to — as the warning screen tells you — “your profile information, photos, your friends’ info, and other content that it requires to work,” whether they need it or not.

In 2007, Adrienne Porter Felt, then a computer science student at the University of Virginia and now a student at U.C. Berkeley, and David Evans, an Associate Professor of Computer Science at the University of Virginia, did a survey of the top 150 Facebook applications and found that “90.7% of applications are being given more privileges than they need” to perform their intended functions.

The researchers haven’t updated those earlier findings, but Evans says he suspects the results would be pretty similar. “If anything, the applications are getting more complex,” he says. “And there is also an emerging model for third-party advertising networks embedded in applications, which has further privacy risks.”

In summary,

Bottom line? Facebook doesn’t call for new principles, Selvas says, just smart application of the old ones. And the constant reminder that you and your employees are in public when you’re on Facebook. As Selvas sums up, “Don’t do anything on Facebook you wouldn’t do in an airport.”