About

Bobby Bhattacharjee is a professor in the Department of Computer Science at the University of Maryland, with an affiliate appointment in the Department of Electrical and Computer Engineering. His research focus includes computer networks, operating systems, and special topics in networking. He has been involved in teaching courses such as CMSC 711 Computer Networks, CMSC 417 Computer Networks, CMSC 412 Operating Systems, and CMSC 818 Special Topics in Networking. He was an Alfred P. Sloan Research Fellow from 2004 to 2006. His academic background includes supervising students who have gone on to positions at institutions such as the University of Wisconsin, Google, Amazon, Deutsche Telekom Labs, and Two Sigma. His contact information includes an office at 4147 A. V. Williams Building, University of Maryland, College Park, MD 20742, with phone number +1 301 405 1658 and email address formatted as per the page instructions.

Research topics

• Computer Science
• Computer Security
• Data science
• Embedded system
• Operating system

Selected publications

• Efficient Routing on Quantum Networks Using Adaptive Clustering

  2024-10-28 · 4 citations

  articleSenior author

  We introduce QuARC, Quantum Adaptive Routing using Clusters, a novel clustering-based entanglement routing protocol that leverages redundant, multi-path routing through multi-particle projective quantum measurements to enable high-throughput, low-overhead, starvation-free entanglement distribution. At its core, QuARC periodically reconfigures the underlying quantum network into clusters of different sizes, where each cluster acts as a small network that distributes entanglement across itself, and the end-to-end entanglement is established by further distributing between clusters. QuARC does not require a-priori knowledge of any physical parameters, and is able to adapt the network configuration using static topology information, and using local (within-cluster) measurements only. We present a comprehensive simulation-based evaluation that shows QuARC is robust against changes to physical network parameters, and maintains high throughput without starvation even as network sizes scale and physical parameters degrade.

  PublisherDOI

• Efficient Routing on Quantum Networks using Adaptive Clustering

  arXiv (Cornell University) · 2024-10-30

  preprintOpen accessSenior author

  We introduce QuARC, Quantum Adaptive Routing using Clusters, a novel clustering-based entanglement routing protocol that leverages redundant, multi-path routing through multi-particle projective quantum measurements to enable high-throughput, low-overhead, starvation-free entanglement distribution. At its core, QuARC periodically reconfigures the underlying quantum network into clusters of different sizes, where each cluster acts as a small network that distributes entanglement across itself, and the end-to-end entanglement is established by further distributing between clusters. QuARC does not require a-priori knowledge of any physical parameters, and is able to adapt the network configuration using static topology information, and using local (within-cluster) measurements only. We present a comprehensive simulation-based evaluation that shows QuARC is robust against changes to physical network parameters, and maintains high throughput without starvation even as network sizes scale and physical parameters degrade.

  PublisherOA PDFDOI

• CoVault artifact

  arXiv (Cornell University) · 2022 · 1 citations

  • Computer Science
  • Computer Science
  • Data science

  Analytics on personal data, such as individuals' mobility, financial, and health data can be of significant benefit to society. Such data is already collected by smartphones, apps and services today, but liberal societies have so far refrained from making it available for large-scale analytics. Arguably, this is due at least in part to the lack of an analytics platform that can secure data through transparent, technical means (ideally with decentralized trust), enforce source policies, handle millions of distinct data sources, and run queries on billions of records with acceptable query latencies. To bridge this gap, we present an analytics platform called CoVault which combines secure multi-party computation (MPC) with trusted execution environment (TEE)-based delegation of trust to be able execute approved queries on encrypted data contributed by individuals within a datacenter to achieve the above properties. We show that CoVault scales well despite the high cost of MPC. For example, CoVault can process data relevant to epidemic analytics for a country of 80M people (about 11.85B data records/day) on a continuous basis using a core pair for every 20,000 people. Compared to a state-of-the-art MPC-based platform, CoVault can process queries between 7 to over 100 times faster, as well as scale to many sources and big data.

  PublisherOA PDFDOI

• SeCloak: ARM Trustzone-based Mobile Peripheral Control

  arXiv (Cornell University) · 2020 · 9 citations

  Senior authorCorresponding
  • Computer Science
  • Computer Science
  • Computer Security

  Reliable on-off control of peripherals on smart devices is a key to security and privacy in many scenarios. Journalists want to reliably turn off radios to protect their sources during investigative reporting. Users wish to ensure cameras and microphones are reliably off during private meetings. In this paper, we present SeCloak, an ARM TrustZone-based solution that ensures reliable on-off control of peripherals even when the platform software is compromised. We design a secure kernel that co-exists with software running on mobile devices (e.g., Android and Linux) without requiring any code modifications. An Android prototype demonstrates that mobile peripherals like radios, cameras, and microphones can be controlled reliably with a very small trusted computing base and with minimal performance overhead.

  PublisherOA PDFDOI

• Finding Safety in Numbers with Secure Allegation Escrows

  2020-01-01 · 1 citations

  preprintOpen accessSenior author

  For fear of retribution, the victim or witness of a crime may be willing to report it only if other victims of the same perpetrator also step forward. Examples include 1) identifying oneself as the victim of sexual harassment, especially by a person in a position of authority or 2) accusing an influential politician, an authoritarian government, or one's own employer of corruption. To handle such situations, legal literature has proposed the concept of an allegation escrow: a neutral third-party that collects allegations, matches them against each other, and discloses them only after reveal thresholds (in terms of number of co-allegers), pre-specified by the allegers, are reached. Until then, allegations and allegers' identities are kept confidential.

  PublisherDOI

• enClosure

  2019-06-12 · 4 citations

  articleOpen access

  New applications enabled by personal smart devices and the Internet-of-Things (IoT) require communication in the context of periods of spatial co-location. Examples of this encounter-based communication (EbC) include social exchange among individuals who shared an experience, and interaction among personal and IoT devices that provide location-based services. Existing EbC systems are limited to communication among participants that share a direct encounter. This paper is inspired by two insights: (1) encounters also enable group communication among devices connected by paths in the encounter graph that is contextual, spontaneous, secure, and does not require users to reveal identifying or linkable information; and (2) addressing communication partners using encounter closures subject to causal, spatial, and temporal constraints enables powerful new forms of group communication. We present the design of enClosure, a service providing group communication based on encounter closures for mobile and IoT applications, and a prototype implementation for Android and the Microsoft Embedded Social Cloud platform. Using real-world traces, we show that enClosure provides a privacy-preserving, secure platform for a wide range of group communication applications ranging from connecting attendees of a large event and virtual guest books to disseminating health risk warnings, lost-and-found, and tracing missing persons.

  PublisherOA PDFDOI

• Composing Abstractions using the null-Kernel

  2019-05-10 · 1 citations

  articleOpen accessSenior author

  research-article Open Access Share on Composing Abstractions using the null-Kernel Authors: James Litton University of Maryland, Max Planck Institute for Software Systems University of Maryland, Max Planck Institute for Software SystemsView Profile , Deepak Garg Max Planck Institute for Software Systems Max Planck Institute for Software SystemsView Profile , Peter Druschel Max Planck Institute for Software Systems Max Planck Institute for Software SystemsView Profile , Bobby Bhattacharjee University of Maryland University of MarylandView Profile Authors Info & Claims HotOS '19: Proceedings of the Workshop on Hot Topics in Operating SystemsMay 2019 Pages 1–6https://doi.org/10.1145/3317550.3321450Published:13 May 2019Publication History 1citation1,283DownloadsMetricsTotal Citations1Total Downloads1,283Last 12 Months200Last 6 weeks13 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

  PublisherOA PDFDOI

• enClosure: Group Communication via Encounter Closures (poster)

  2019-06-12 · 1 citations

  articleOpen access

  New applications enabled by personal smart devices and the Internet-of-Things (IoT) require communication in the context of an encounter (a period of spatial co-location). However, existing encounter-based communication (EbC) systems are limited to communication among participants that share a direct encounter. This work is inspired by two insights: (1) encounters also enable group communication among devices connected by paths in the encounter graph that is contextual, spontaneous, secure, and privacy-preserving; and (2) addressing communication partners using encounter closures subject to causal, spatial, and temporal constraints enables powerful new forms of group communication. We present the design of enClosure, a service providing group communication based on encounter closures for mobile and IoT applications, and a prototype implementation for Android and the Microsoft Embedded Social Cloud platform. Using real-world traces, we show that enClosure provides a privacy-preserving, secure platform for a wide range of group communication applications ranging from connecting attendees of a large event to disseminating health risk warnings and tracing missing persons.

  PublisherOA PDFDOI

• TxProbe: Discovering Bitcoin’s Network Topology Using Orphan Transactions

  Lecture notes in computer science · 2019-01-01 · 12 citations

  preprintOpen accessSenior author
  PublisherOA PDFDOI

• SATE: Robust and Private Allegation Escrows.

  2018-10-23

  articleSenior author
  Publisher

Frequent coauthors

• Peter Druschel

  27 shared

• Neil Spring

  Menlo School

  24 shared

• Peter J. Keleher

  University of Maryland, College Park

  17 shared

• Dave Levin

  15 shared

• Seungjoon Lee

  15 shared

• Richard J. La

  14 shared

• Mark A. Shayman

  University of Maryland, College Park

  14 shared

• Suman Banerjee

  University of Wisconsin–Madison

  14 shared

Labs

• CLIP LabPI

Awards & honors

• Sloan Research Fellowship (2004)
• NSF CAREER Mentions (2001)
• SIGCOMM 2009 Best Student Paper Award (2009)
• Resource Discovery Techniques in Distributed Desktop Grid En…
• Microsoft Live Labs Fellowship (2007)