Ranjit Kumaresan

Welcome! I recently joined Microsoft Research Redmond. Until October 2016, I was a postdoc at MIT CSAIL under Prof. Vinod Vaikuntanathan. Previously I completed my Ph.D. in Computer Science at the University of Maryland under Prof. Jonathan Katz and a postdoc at the Technion under Prof. Yuval Ishai. I did my undergrad at IIT Madras and was advised by Prof. C. Pandu Rangan.

Contact Information

Email: vranjit@gmail.com
Twitter: @vranjit27

Research Overview

My current research interests are in secure computation and Bitcoin. Recently I have worked on using Bitcoin to design fair protocols. I have also invented several new techniques to improve the efficiency of generic protocols for secure computation. One direction that I'm interested in exploring further is the use of Bitcoin to design cryptographic protocols that offer new capabilities.

Here's my CV.

Here are some recent invited talks:

Publications

Amortizing Secure Computation with Penalties
with Iddo Bentov
ACM CCS 2016
Improvements to Secure Computation with Penalties
with Vinod Vaikuntanathan and Prashant Vasudevan
ACM CCS 2016
Efficient Batched Oblivious PRF with Applications to Private Set Intersection
with Vladimir Kolesnikov, Mike Rosulek, and Ni Trieu
ACM CCS 2016
Network Oblivious Transfer
with Srinivasan Raghuraman and Adam Sealfon
Crypto 2016
On Cut-and-Choose Oblivious Transfer and Its Variants
with Vladimir Kolesnikov
Asiacrypt 2015
How to Use Bitcoin to Play Decentralized Poker
with Iddo Bentov and Tal Moran
ACM CCS 2015
Secure Computation with Minimal Interaction, Revisited
with Yuval Ishai, Eyal Kushilevitz, and Anat Paskin-Cherniavsky
Crypto 2015 (slides, talk)
How to Use Bitcoin to Design Fair Protocols
with Iddo Bentov
Crypto 2014 (slides, talk)
Amortizing Garbled Circuits
with Yan Huang, Jonathan Katz, Vladimir Kolesnikov, and Alex Malozemoff
Crypto 2014 (slides)
On the Complexity of UC Commitments
with Juan Garay, Yuval Ishai, and Hoeteck Wee
Eurocrypt 2014
On the Cryptographic Complexity of the Worst Functions
with Amos Beimel, Yuval Ishai, and Eyal Kushilevitz
TCC 2014 (slides, talk)
Improved OT Extension for Transferring Short Secrets
with Vladimir Kolesnikov
Crypto 2013 (slides, talk)
Multi-Client Non-interactive Verifiable Computation
with Seung-Geol Choi, Jonathan Katz, and Carlos Cid
TCC 2013 (slides)
On the Security of the 'Free-XOR' Technique
with Seung Geol Choi, Jonathan Katz, and Hong-Sheng Zhou
TCC 2012 (slides)
Adaptively Secure Broadcast, Revisited
with Juan Garay, Jonathan Katz, and Hong-Sheng Zhou
PODC 2011 (slides)
The Round Complexity of Verifiable Secret Sharing: The Statistical Case
with Arpita Patra and C. Pandu Rangan
Asiacrypt 2010 (slides)
Authenticated Broadcast with a Partially Compromised Public Key Infrastructure
with Dov Gordon, Jonathan Katz, and Arkady Yerukhimovich
SSS 2010 (slides)
(Invited to a Special Issue of Information and Computation 2014)
Improving the Round Complexity of VSS in Point-to-Point Networks
with Jonathan Katz and Chiu-Yuen Koo
ICALP 2008 (slides)
(Appeared in Information and Computation 2009)
On Exponential Lower Bound for Protocols for Reliable Communication in Networks
with Kannan Srinathan and C. Pandu Rangan
ICITS 2007

Ph.D. Thesis

Broadcast and Verifiable Secret Sharing: New Security Models and Round Optimal Constructions
University of Maryland, 2012
Includes results from the following papers (see above for full publication information) and also some additional, unpublished results:
  • Adaptively Secure Broadcast, Revisited
  • The Round Complexity of Verifiable Secret Sharing: The Statistical Case
  • Authenticated Broadcast with a Partially Compromised Public Key Infrastructure
  • Improving the Round Complexity of VSS in Point-to-Point Networks

About me

ranjit

News

I am on the PC for Indocrypt 2017, Eurocrypt 2017, CCS 2016, ICITS 2016, and SCN 2016. I was on the PC for ACNS 2015
I'll be speaking at DIMACS Workshop on Cryptography and Interactions in Jul'16.
I'll be speaking at MPC-2016 in Jun'16. Update: Unfortunately I couldn't attend this workshop.

Recent Talks

"How to Use Bitcoin to Play Decentralized Poker" at CCS (Oct'15). See this Medium post by Frank Wang.
"Secure Computation with Minimal Interaction, Revisited" at Crypto (Aug'15).

Education

Ph.D., U Maryland 2012
M.S., U Maryland 2011
B.Tech, IIT Madras 2006

Work

MIT 2015-
Postdoc with V. Vaikuntanathan
Technion 2012-2014
Postdoc with Y. Ishai
Bell Labs Summer 2011
Intern with V. Kolesnikov
U Maryland 2006-2012
GRA/GTA with J. Katz

Twitter