We are pleased to share an upcoming THaW paper to appear next month at  IEEE Workshop on Data Usage Management, a workshop colocated with the IEEE Symposium on Security & Privacy in May 2014.

Abstract: Our genome determines our appearance, gender, diseases, reaction to drugs, and much more. It not only contains information about us but also about our relatives, past generations, and future generations. This creates many policy and technology challenges to protect privacy and manage usage of genomic data. In this paper, we identify various features of genomic data that make its usage management very challenging and different from other types of data. We also describe some ideas about potential solutions and propose some recommendations for the usage of genomic data. [pdf]

The THaW team is pleased to announce the third of its three papers to be presented at the IEEE Symposium on Security & Privacy (aka ‘Oakland’) in May.

ZEBRA: Zero-Effort Bilateral Recurring Authentication
Shrirang Mare, Andrés Molina-Markham, Cory Cornelius, Ronald Peterson, and David Kotz

Abstract: Common authentication methods based on passwords, tokens, or fingerprints perform one-time authentication and rely on users to log out from the computer terminal when they leave. Users often do not log out, however, which is a security risk. The most common solution, inactivity timeouts, inevitably fail security (too long a timeout) or usability (too short a timeout) goals. One solution is to authenticate users continuously while they are using the terminal and automatically log them out when they leave. Several solutions are based on user proximity, but these are not sufficient: they only confirm whether the user is nearby but not whether the user is actually using the terminal. Proposed solutions based on behavioral biometric authentication (e.g., keystroke dynamics) may not be reliable, as a recent study suggests.

To address this problem we propose ZEBRA. In ZEBRA, a user wears a bracelet (with a built-in accelerometer, gyroscope, and radio) on her dominant wrist. When the user interacts with a computer terminal, the bracelet records the wrist movement, processes it, and sends it to the terminal. The terminal compares the wrist movement with the inputs it receives from the user (via keyboard and mouse), and confirms the continued presence of the user only if they correlate. Because the bracelet is on the same hand that provides inputs to the terminal, the accelerometer and gyroscope data and input events received by the terminal should correlate because their source is the same – the user’s hand movement. In our experiments ZEBRA performed continuous authentication with 85% accuracy in verifying the correct user and identified all adversaries within 11 s. For a different threshold that trades security for usability, ZEBRA correctly verified 90% of users and identified all adversaries within 50 s.

Note: since the time this paper was published we have learned of a relevant trademark on the name “Zebra”. Thus, we have renamed our approach “BRACE” and will use that name in future publications.

[view pdf]

The THaW team is pleased to announce the second of its three papers to be presented at the IEEE Symposium on Security & Privacy (aka ‘Oakland’) in May.

Dynamic Searchable Encryption via Blind Storage
Muhammad Naveed, Manoj Prabhakaran, Carl A. Gunter

Abstract: Dynamic Searchable Symmetric Encryption allows a client to store a dynamic collection of encrypted documents with a server, and later quickly carry out keyword searches on these encrypted documents, while revealing minimal information to the server. In this paper we present a new dynamic SSE scheme that is simpler and more efficient than existing schemes while revealing less information to the server than prior schemes, achieving fully adaptive security against honest-but-curious servers.

We implemented a prototype of our scheme and demonstrated its efficiency on datasets from prior work. Apart from its concrete efficiency, our scheme is also simpler: in particular, it does not require the server to support any operation other than upload and download of data. Thus the server in our scheme can be based solely on a cloud storage service, rather than a cloud computation service as well, as in prior work.

In building our dynamic SSE scheme, we introduce a new primitive called Blind Storage, which allows a client to store a set of files on a remote server in such a way that the server does not learn how many files are stored, or the lengths of the individual files; as each file is retrieved, the server learns about its existence(and can notice the same file being downloaded subsequently), but the file’s name and contents are not revealed. This is a primitive with several applications other than SSE, and is of independent interest.

[view pdf]