Assistant Project

Krishna P. N. Puttaswamy

*** ****** ****, *** *** Email: ********@**.****.***

Goleta, CA 93117 Phone: 805-***-****

http://www.cs.ucsb.edu/~krishnap

Security and privacy, cloud computing, distributed systems and applications, Internet

Research

measurement.

Interests

Ph.D. in Computer Science, Sept. 2005 - Present

Education

Department of Computer Science, University of California at Santa Barbara

Bachelor of Engineering (Computer Engineering), May 2003

National Institute of Technology Karnataka, Surathkal, Karnataka, India

Research Toward Con dentiality in Third-Party Compute Clouds

By o ering high availability and elastic access to resources, third-party cloud infrastruc-

Experience

tures such as Amazon AWS and Microsoft Azure are revolutionizing the way today s

businesses operate. However, data con dentiality concerns are hindering cloud adap-

tion by many businesses. In this project, we have developed a novel approach for

businesses to obtain elasticity from the cloud while also obtaining data con dential-

ity guarantees. We are now building developer tools to enable businesses to adapt

our approach automatically into their deployed applications with very little developer

support.

Collaborative Editing of Fidelity Reduced Documents on Mobile Devices

In this project, we are building a new framework to support editing shared documents

on mobile devices. Three high-level requirements in uenced its design. Namely, a) the

need to adapt content, especially textual content, on the y according to the quality of

the network connection and the form factor of each device. b) Support for concurrent,

uncoordinated editing on di erent devices, whose e ects will later be merged on all

devices in a convergent and consistent manner without sacri cing the semantics of

the edits. And c) exible replication that accommodates both device-to-device and

cloud-mediated synchronization. The framework supports on-the-go editing for XML

documents, such as documents in Microsoft Word and other commonly used formats.

Anonymity-Preserving Data Aggregation

Data aggregation is a key aspect in many distributed applications. In these appli-

cations, user anonymity is a key concern of the participants. In the absence of an

assurance of anonymity, users may be reluctant to participate. In this project, we

developed novel aggregation techniques to perform data aggregation while preserving

user anonymity. In addition, we bound the data pollution caused by malicious users

behind the cloak of anonymity, while maintaining overall system scalability using a

novel multi-tree data structure for aggregation.

Privacy Protection for Social Content-Sharing Applications

Online social network applications are popular means for interaction, communication

and collaboration between friends. While sharing content promotes the overall utility

of these applications, many users are wary of being associated with their sensitive data.

In this project, we identi ed the key attacks possible due to compromised third-party

application servers or due to compromised user accounts (by botnets, for example)

that weaken user privacy, proposed techniques to defend against these attacks, and

validated the techniques using datasets from several social networks and applications.

Flexible and Robust Anonymous Communication

Deployed anonymous systems such as Tor use static end-to-end paths for communica-

tion. These static paths are brittle and must be rebuilt following a failure of any node

on the path. This is costly in terms of resource overhead and also leaks information

to various attacks leading to signi cant degradation of anonymity over long sessions.

In this project, we developed a new abstraction for building anonymous systems called

hooks. We showed that hooks can build robust anonymous paths, and provide orders

of magnitude stronger anonymity compared to existing systems.

Improving Rare Object Search in Unstructured Overlays

Existing peer-to-peer search protocols are e ective in locating highly popular objects,

but they fail to locate a signi cant portion of the rare objects existing in the network.

High recall for these rare objects would drastically improve the user experience, and

make these networks the ideal distribution infrastructure for user-generated content

such as home videos and photo albums. In this work, we developed simple techniques

that can improve search recall for rare objects while minimizing the overhead incurred

by participating peers. We proposed several multihop index replication strategies that

improve the performance of peer-to-peer overlays by orders of magnitude in both lookup

success and lookup overhead.

Securing Structured Overlays Against Identity Attacks

To support applications such as global-scale storage, structured peer-to-peer (P2P)

overlay networks use key-based routing (KBR) to choose servers and perform application

tasks. KBR, however, is vulnerable to identity attack. By hijacking and responding to

KBR messages, malicious peers can usurp application connections, and thus severely

disrupt overlay applications. Attackers can assume arbitrary application roles such as

storage server for a speci c le or root of a speci c multicast tree through this attack.

The impact is ampli ed when this attack is launched by colluding peers following a

Sybil or Eclipse attack. In this work, we studied these identity attacks, analyze the costs

to perform them, and proposed lightweight mechanisms to detect and evade attackers.

Krishna P. N. Puttaswamy, Ranjita Bhagwan and Venkat Padmanabhan Anonymity-

Publications

Preserving Data Aggregation using Anonygator To Appear: ACM/IFIP/USENIX

11th International Middleware Conference (Middleware 2010) Bangalore, India. Novem-

ber 2010

Krishna P. N. Puttaswamy, Cathy Marshall, Venugopalan Ramasubramanian, Patrick

Stuedi, Douglas B. Terry and Ted Wobber Docx2Go: Collaborative Editing of Fidelity

Reduced Documents on Mobile Devices To Appear: 8th Annual International Con-

ference on Mobile Systems, Applications and Services (MobiSys 2010) San Francisco,

CA, USA. June 2010

Venugopalan Ramasubramanian, Kaushik Veeraraghavan, Krishna P. N. Puttaswamy,

Thomas L. Rodehe er, Douglas B. Terry and Ted Wobber Fidelity-Aware Replication

for Mobile Devices IEEE Transactions on Mobile Computing (TMC), 2010

Krishna P. N. Puttaswamy and Ben Y. Zhao Preserving Privacy in Location-based

Mobile Social Applications 11th Workshop on Mobile Computing Systems and Appli-

cations (ACM HotMobile) Annapolis, MD, February 2010

Krishna P. N. Puttaswamy, Alessandra Sala, and Ben Y. Zhao StarClique: Guaran-

teeing User Privacy in Social Networks Against Intersection Attacks ACM Conference

on emerging Networking EXperiments and Technologies (CoNEXT 2009) Rome, Italy,

December 2009

Christo Wilson, Bryce Boe, Alessandra Sala, Krishna Puttaswamy and Ben Y. Zhao

User Interactions in Social Networks and their Implications ACM EuroSys 2009,

Nuremburg, Germany, April 2009

Krishna P. N. Puttaswamy, Alessandra Sala, Omer Egecioglu, and Ben Y. Zhao

Rome: Performance and Anonymity using Route Meshes IEEE INFOCOM 2009

Minisymposium, Rio de Janeiro, Brazil, April 2009

Krishna P. N. Puttaswamy, Alessandra Sala, and Ben Y. Zhao

Improving Anonymity using Social Links IEEE Workshop on Secure Network Pro-

tocols (NPSec 2008), Orlando, FL, October 2008

Krishna P. N. Puttaswamy, Alessandra Sala, Christo Wilson, and Ben Y. Zhao

Defending Anonymity against Predecessor Attacks in Bluemoon IEEE International

Conference on Network Protocols (ICNP 2008), Orlando, FL, October 2008

Krishna P. N. Puttaswamy, Ben Y. Zhao and Haitao Zheng,

Securing Structured Overlays Against Identity Attacks, IEEE Transactions on Par-

allel and Distributed Systems (TPDS), 2008

Krishna P. N. Puttaswamy, Alessandra Sala and Ben Y. Zhao,

Searching for Rare Objects using Index Replication Proceeding of 27th IEEE Inter-

national Conference on Computer Communications (INFOCOM 2008), Phoenix, AZ,

April 2008

Krishna P. N. Puttaswamy and Ben Y. Zhao,

A Case for Unstructured Distributed Hash Tables Proceedings of IEEE Global Inter-

net Symposium (GI 2007), Anchorage, AK, May 2007

Krishna P. N. Puttaswamy, Christopher Kruegel and Ben Y. Zhao Silverline: Toward

Papers in

Con dentiality in Third-Party Clouds

Submission

Krishna P. N. Puttaswamy, Christopher Kruegel and Ben Y. Zhao Silverline: To-

Posters

ward Con dentiality in Third-Party Clouds Poster at the 7th USENIX Symposium

on Network Design and Implementation (NSDI 2010) San Jose, CA, April 2010

Krishna P. N. Puttaswamy, Christopher Kruegel and Ben Y. Zhao Protecting Private

Data in Third-Party Compute Clouds Poster at the 11th Workshop on Mobile Com-

puting Systems and Applications (ACM HotMobile) Annapolis, MD, February 2010

Professional University of California at Santa Barbara

Research Assistant Sept. 2006 - Present

Experience

Advisor: Ben Y. Zhao

Microsoft Research, India

Research Intern May 2010 - July 2010

Research Intern and June 2008 - Sept 2008

Mentors: Ranjita Bhagwan and Venkat Padmanabhan

Microsoft Research, Silicon Valley

Research Intern June 2009 - Sept 2009

Mentor: Venugopalan Rama Ramasubramanian

HP Laboratories

Research Intern June 2006 - Sept. 2006

Mentor: Rick McGeer

University of California at Santa Barbara

Teaching Assistant Sept. 2005 - June 2006

Microsoft India R&D Center

Software Design Engineer April 2004 - Aug. 2005

D.E.Shaw Software India Pvt. Ltd.

Member - Information Technology Aug. 2003 - April 2004

Fall 2005 Teaching Assistant, UCSB

Teaching

Undergraduate Operating Systems (CS170), Taught by: Ben Y. Zhao

Experience

Winter 2006 Teaching Assistant, UCSB

Introduction to Computer Programming (CS10), Taught by: C. Michael Costanzo

Spring 2006 Teaching Assistant, UCSB

Network Computing (CS176C), Taught by: Ben Y. Zhao

Reviewer for ICDCS 2006, DSN 2007, Concurrency and Computation: Practice and

Professional

Experience 2007, Journal for Advances in Multimedia 2007, IH 2008, ICDE 2009,

Service

PPOPP 2009, INFOCOM 2009, SIGCOMM CCR 2009, IEEE Transactions on Wire-

less Communications 2009, SecureComm 2009, P2P 2009, SRDS 2009, Euro-Par 2009,

INFOCOM 2010, and IPDPS 2010.

Awarded student travel grant to attend OSDI 2006, NSDI 2010, and MobiSys 2010.

Awards And

Ranked 12th (out of 100,000) in the state level engineering entrance exam, 1999.

Honors

Ranked among the top 2% of all students in IIT-JEE, 1999.

Recipient of Best Outgoing Student Award among 400 students, Sarvodaya Pre-

University College, Tumkur.

Contact this candidate