Selected Publications

We introduce MASHaBLE, a mobile application that enables participants to discover and interact with nearby users if and only if they belong to the same secret community. We use direct peer-to-peer communication over Bluetooth LE, rather than relying on a central server. We discuss the specifics of implementing secret handshakes over Bluetooth LE and present our prototype implementation.
In MobiCom’16

Modern mobile platforms like Android enable applications to read aggregate power usage on the phone. This information is considered harmless and reading it requires no user permission or notification. We show that by simply reading the phone's aggregate power consumption over a period of a few minutes an application can learn information about the user's location. Aggregate phone power consumption data is extremely noisy due to the multitude of components and applications that simultaneously consume power. Nevertheless, by using machine learning algorithms we are able to successfully infer the phone's location. We discuss several ways in which this privacy leak can be remedied.
In USENIX Security ‘15

We show that the MEMS gyroscopes found on modern smart phones are sufficiently sensitive to measure acoustic signals in the vicinity of the phone. The resulting signals contain only very low-frequency information (<200Hz). Nevertheless we show, using signal processing and machine learning, that this information is sufficient to identify speaker information and even parse speech. Since iOS and Android require no special permissions to access the gyro, our results show that apps and active web content that cannot access the microphone can nevertheless eavesdrop on speech in the vicinity of the phone.
In USENIX Security ‘14

Recent Publications

Selected Talks


Towards (even more) practical Faust: Polyphony, Portamento and Pitch Bend in Faust VSTi-s

The Faust compiler and the toolset provided along with it enable generating standalone synthesizers and plug-ins for various architectures. We noticed that while being a very useful tool for sound synthesis its VSTi plug-ins lack several critical features for practical usage in combination with music production software and digital audio workstations (DAW). We focus on the VST architecture as one that has been used traditionally and is supported by many tools and add several important features: polyphony, note history and pitch-bend support.

Tight Schedule: Deadline Constrained Scheduling of OpenRadio on a Multi-Core Platform

One of the challenges of real-time, performance critical multi-core systems is the efficient scheduling of executed tasks. The scheduling problem consists of assigning the tasks to the different cores and deciding upon the order of execution. A special case is heterogeneous multi-core platforms where the cost of execution varies among the different processors. In this paper we present static and dynamic scheduling approaches, discuss their pros and cons and demonstrate a dynamic deadline-oriented scheduling algorithm with a low processing footprint. We apply the two approaches to the OpenRadio real-time Wi-Fi platform operating at high rates and demonstrate obtaining of feasible schedules. Using our scheduling algorithm we examine implications of hardware parameters on wi-fi processing feasibility. We also propose several possible improvements to the dynamic scheduling algorithm.

Classical Analysis of Cavity Optomechanics

We present a classical analysis of a mechanical oscillator subject to the radiation pressure force due to light circulating inside a driven optical cavity. Our analysis is related to the problem of cooling an optomechanical setup to degrees near the ground state of mechanical motion according to quantum theory. Achieving this could provide an insight into quantum phenomena occurring in macro-scale setups. Dynamical backaction based on optical radiation pressure could be employed to reduce thermally excited fluctuations. We review the motion equations system and its steady state solution. We also show numerical simulation results, demonstrating different motion modes of such optomechanical setup.