News

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[07/22/16]Our paper analyzing private key sharing in the SSL ecosystem was accepted at CCS '16!
[05/07/16]Our paper on Time Reversal for Wireless Power Transfer won the Best Paper Award at IEEE WPTC 2016!
[04/11/16]I've accepted an offer to begin my Ph.D. at MIT in Fall 2016!
[01/29/16]Our paper on Picocenter, a new cloud computing infrastructure was accepted at EuroSys'16!
[12/18/15]I was selected as an honorable mention for the CRA Outstanding Undergraduate Researcher Award. Many thanks to Dave Levin and Alan Mislove for nominating me!
[11/20/15]I presented our work on Ting at the Fall 2015 DCAPS seminar.

About Me

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I am a fourth-year undergraduate student working in the Network and Systems Lab at the University of Maryland under the mentorship of Dave Levin. I am also a member of Gemstone Team TESLA, supervised by Dr. Steven Anlage.

My research interests lie at the intersection of networking, systems, and security. I am currently focused on improving the practicality and efficiency of cloud computing containers and analyzing the security of the web's public key infrastructure. I am also working on new techniques for long-range wireless power transfer that are feasible, practical, and safe for everyday use.

Publications

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Measurement and Analysis of Private Key Sharing in the HTTPS Ecosystem
Frank Cangialosi, Taejoong Chung, David Choffnes, Dave Levin, Bruce Maggs, Alan Mislove, Christo Wilson
To appear at  CCS'16  (ACM Conference on Computer and Communications Security), Vienna, Austria
PDF Project Slides Poster (SoS'16)
Show Abstract
The semantics of authentication in the web's PKI are rather straightforward: if Alice has a certificate binding Bob's name to a public key, and if a remote entity can prove knowledge of Bob's private key, then (barring key compromise) that remote entity must be Bob. However, in reality, many websites-and the majority of the most popular ones-are hosted at least in part by third-parties such as Content Distribution Networks (CDNs) or web hosting providers. Put simply: administrators of websites who deal with critically sensitive user data are giving their private keys to thirdparties. Critically, this sharing of keys is undetectable by most users, and widely unknown even among researchers. In this paper, we perform a large-scale measurement study of administrators' decisions regarding key sharing with third-party hosting providers and the impact this sharing has on key management. We analyze the prevalence with which websites trust third-party hosting providers with their secret keys, as well as the impact that this trust has on responsible key management practices, such as revocation.

Time Reversed EM Wave Propagation as a Novel Method of Wireless Power Transfer
Frank Cangialosi, Tyler Grover, Patrick Healey, Tim Furman, Andrew Simon, Steven Anlage
WPTC'16  (IEEE Wireless Power Transfer Conference), Aveiro, Portugal
Best Paper Award
PDF Project Slides Poster (WPTC'16)
Show Abstract
We investigate the application of time reversed electromagnetic wave propagation to transmit energy to a moving target in a reverberant environment. "Time reversal" is a signal focusing method that exploits the time reversal invariance of the lossless wave equation to focus signals on a small region inside a complex scattering environment. In this work, we explore the properties of time reversed microwave pulses in a low-loss raychaotic chamber. We measure the spatial profile of the collapsing wavefront around the target antenna, and demonstrate that time reversal can be used to transfer energy to a receiver in motion. We discuss the results of these experiments, and explore their implications for a wireless power transmission system based on time reversal.

Picocenter: Supporting Long-Lived, Mostly-Idle Applications in Cloud Environments
Liang Zhang, James Litton, Frank Cangialosi, Theophilus Benson, Dave Levin, Alan Mislove
EuroSys'16  (European Conference on Computer Systems), London, UK
PDF Project Slides Poster (SOCC'15)
Show Abstract
Cloud computing has evolved to meet user demands, from arbitrary VMs offered by IaaS to the narrow application interfaces of PaaS. Unfortunately, there exists an intermediate point that is not well met by today's offerings: users who wish to run arbitrary, already available binaries (as opposed to rewriting their own application for a PaaS) yet expect their applications to be long-lived but mostly idle (as opposed to the always-on VM of IaaS). For example, end users who wish to run their own email or DNS server. In this paper, we explore an alternative approach for cloud computation based on a process-like abstraction rather than a virtual machine abstraction, thereby gaining the scalability and efficiency of PaaS along with the generality of IaaS. We present the design of Picocenter, a hosting infrastructure for such applications that enables use of legacy applications. The key technical challenge in Picocenter is enabling fast swapping of applications to and from cloud storage (since, by definition, applications are largely idle, we expect them to spend the majority of their time swapped out). We develop an ActiveSet technique that prefetches the application's predicted memory working set when reviving an application. An evaluation on EC2 demonstrates that using ActiveSet, Picocenter is able to swap in applications in under 250 ms even when they are stored in S3 while swapped out.

Ting: Measuring and Exploiting Latencies Between All Tor Nodes
Frank Cangialosi, Dave Levin, Neil Spring
IMC'15  (Internet Measurement Conference), Tokyo, Japan
PDF Project Slides Poster
Show Abstract
Tor is a peer-to-peer overlay routing network that achieves unlinkable communication between source and destination. Unlike traditional mix-nets, Tor seeks to balance anonymity and performance, particularly with respect to providing lowlatency communication. As a result, understanding the latencies between peers in the Tor network could be an extremely powerful tool in understanding and improving Tor's performance and anonymity properties. Unfortunately, there are no practical techniques for inferring accurate latencies between two arbitrary hosts on the Internet, and Tor clients are not instrumented to collect and report on these measurements. In this paper, we present Ting, a technique for measuring latencies between arbitrary Tor nodes from a single vantage point. Through a ground-truth validation, we show that Ting is accurate, even with few samples, and does not require modifications to existing clients. We also apply Ting to the live Tor network, and show that its measurements are stable over time. We demonstrate that the all-pairs latency datasets that Ting permits can be applied in disparate ways, including faster methods of deanonymizing Tor circuits and efficiently finding long circuits with low end-to-end latency.

Teaching (Assistant)

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