Cryptography, Security and Privacy Group


The CrySP Group is a part of the Deparment of Computer Science and Automation at Indian Institute of Science.


MAY 2019 We're organising a reading group on Quantum Cryptography this summer. Check it out here.

Mar 2018 Our paper Privacy Amplification from Non-malleable Codes is on eprint. Check it out [pdf]
Jan 2018 Our paper on Non-malleable Randomness Encoders is accepted to Eurocrypt 2018! Check out the paper! [pdf]
Jan 2018 We're excited to be organizing the IISc-IACR school on Information-theoretic Cryptography. We look forward to seeing you there!
Nov 2017 Our TCC 2017 paper has been invited to Journal of Cryptology. Thanks, TCC and JoC Committees!
Oct 2017 We've posted our latest paper on Non-malleable Randomness Encoders on eprint. [pdf]
Aug 2017 Our paper on Four-state Non-malleable Codes is accepted to TCC 2017! Check out the paper and/or the presentation! [pdf] [slides]


Bhavana KanukurthiFaculty

Bhavana has worked on a range of problems in Cryptography and Security. Some recent examples include building secure and efficient auditing mechanisms for data stored on a remote cloud, making systems resilient to side-channel attacks and using untrusted servers to reliably run one's computation. She received her PhD from Boston University in 2011 and has worked as a Post-Doctoral Researcher at UCLA. She recieved an INSPIRE Award for young faculty from the Department of Science and Technology and a Research Excellence Award from the Department of Computer Science at Boston University.


Sruthi Sekar MSc and PhD

Sruthi is currently an Integrated Master and PhD student at Mathematics Department, IISc. She received her Bachelor's degree in Mathematics from Lady Shri Ram College, Delhi in 2014. Her current work in the Master's thesis is on Non-malleable codes, which combines Coding theory and Cryptography. She likes to play keyboard and loves photography.

Email: fehguv.frxne1@tznvy.pbz

Sai Lakshmi BhavanaPh.D

Sai Lakshmi Bhavana is a PhD student at IISC. Prior to working here, she got her Integrated Dual Degree in Computer Science and Engineering from Indian Institute of Technology (Banaras Hindu University) Varanasi. Her current research focusses on Non-Malleable codes.


Rohit Chatterjee UG and MSc

Rohit Chatterjee is an Integrated UG and Master's in mathematics. His current research interests lie in information theoretic secure computation and he pursues it with Pr.Bhavana Kanukurthi and Pr.Himanshu Tyagi. Rohit's other interests include books and football. Rohit realizes that he likes to talk in third person.

Email: ebuvgpunggrewrr94@tznvy.pbz

Abhishek Shetty UG

Abhishek Shetty is currently an Undergraduate student, majoring in Mathematics. He is currently working on Key Dependant Message Security.

Email: nfurggl1995@tznvy.pbz

Ananth Narayan Intern

Ananth is a Research Assistant working under Dr. Bhavana. He received his Bachelor's Degree in Computer Science from BITS Pilani, Goa in 2016. His interests include Secure Deduplication and Algorithms. In his free time he likes Competitive Programming, Frisbee and Football. He was part of Indian National Frisbee team, 2016.

Email: nanagu360@tznvy.pbz

Mukul Kulkarni Intern

Mukul R. Kulkarni is a doctoral student at the University of Maryland, College Park studying under the guidance of Dr. Dana Dachman-Soled. He received his MTech from Indian Institute of Technology (IIT), Bombay in 2014, after graduating as BE from University of Pune. He served as SAP-BASIS consultant for Accenture between 2009 to 2011, during which he was awarded several professional accolades. His research interests involve Tamper Resilient Cryptography and Lattice based Cryptography. Mukul was also an integral member of the Scilab team for FOSSEE project at IIT Bombay, which aims to improve the quality of instruction and learning in India. In addition to his research, he has actively participated in variety of cultural activities as leading team member. He enjoys playing soccer and writing. Mukul has also completed a diploma in German language. He is inspired by prospects in educational research related to free and open-source software, as well as MOOCs.
Mukul is a summer intern at CrySP and will be working with Dr. Bhavana Kanukurthi from June 2017 till August 2017.

Email: zhxhy@grecznvy.hzq.rqh

Abhishek Kumar Intern

Abhishek Kumar is a UG student majoring in CSE at IIT Kanpur. He is currectly doing his intershship at IISc under Dr.Bhavana during summer 2017. He is currently exploring Multi-party computation, Oblivious Transfer and Private Set Intersection. He is also interested in Game Theory and likes coding. He loves reading books and watching Cricket.

Email: gurnouvfurx763@tznvy.pbz

Marilyn George ME

Marilyn George was an M.E. student at CrySP from 2014 - 2016. Her M.E. thesis focused on Searchable Encryption Systems. She is currently a Research Fellow at Microsoft Research, India. Prior to joining IISc, she completed her bachelor's in Computer Science and Engineering at the National Institute of Technology in Calicut. Marilyn likes to read books and claim that they are better than the movie. (⌐■_■)


Cressida Hamlet ME

Cressida Hamlet was an M.E. student at CrySP from 2014 - 2016. Her M.E. thesis focused on Blind Signatures. She is currently working at Nvidia. Prior to joining IISc, she completed her Bachelor's in Computer Science and Engineering at the National Institute of Technology in Calicut.


Nithin V Nath ME

Nithin was an M.E. student at CrySP from 2014 - 2016. His M.E. thesis focused on Secure Deduplication. He is currently working at Adobe. Prior to IISc, he received his bachelor's degree in Computer Science and Engineering from National Institute of Technology Calicut. Nithin aspires to improve his introduction and make it more interesting.


Srinivasan Raghuraman Intern

Srinivasan Raghuraman was an intern at CrySP during the Summmer of 2015. During his internship, he worked on Non-malleable Codes. (Srini received his bachelor's degree from IIT Madras and is pursuing his PhD in Cryptography at MIT.)

Our group contributes to various projects of national importance and collaborates closely with the industry. One such collboration resulted in the creation of Online Lecture for Discrete Mathematics. These lectures are a part of Microsoft's Massively Empowered Classroms initiative. Our research is funded, in part, through generous research grants received from Department of Science and Technology and Department of Information Technology.
E0248: Theoretical Foundations of Cryptography, Fall 2017

Instructor: Dr.Bhavana Kanukurthi

Class timimgs: 9:30 - 11 Monday, Wednesday

  Lecture 1 (07/8/17): Introduction to Cryptography
  Lecture 2 (09/8/17): Limitations of Information-theoretic Cryptography [Section 1.3 of Pass-shelat]
  Lecture 3 (14/8/17): Perfect Secrecy [Contd.], Computational hardness and One-way Functions [Sections 2.1-2.2 of Pass-shelat]
  Lecture 4 (16/8/17): One-way functions (contd.)
  Lecture 5 (21/8/2017) One-way functions continued. [In this lecture and the previous lecture, we proved several lemmas regarding one-way functions. Two of these appear in
          Problem Set 2 [Problems 1 and 2].]

  Lecture 6 (23/8/2017) Hardness Amplification. [We covered Section 2.4.3 of Pass-shelat. Reading the rest of Section 2.4 is recommended.]
  Lecture 7 (28/8/2017) Hardness Amplification contd. Introduced Pseudo-randomness and computational indistinguishability.
  Lecture 8 (30/8/2017) [Covered by OSL Bhavana] Collection of One-way Functions.[Sections 2.5-2.7,2.9 of Pass-shelat]
  Lecture 9 (4/9/2017) [Covered by Sruthi Sekar] Basic probability theory overview.
  Lecture 10 (6/9/2017) Computational Indistinguishability and Pseudo-randomness. [Pointers to lecture notes will be put up after next class.
  Lecture 11 (11/9/2017) Hard-core predicates and Pseudorandomness definitions (next-bit unpredictability and computational indistinguishability) [See Lec 12 handout and reading list]
  Lecture 12 (13/9/2017) Intro to Hybrid arguments via equivalence of PRG definitions. [Slides based on Leo Reyzin's Lecture Notes; Suggested reading: Reyzin's notes for Lec#2 and Lec#3]
  Class cancelled on 18/9/2017
  Lecture 13 (20/9/2017) Recap of Lec 12/PRG with one-bit stretch/Secure Encryption [Pass-shelat Sections 3.3.1-3.3.4, 3.5 - 3.7]
  Lecture 14 (25/9/2017) Expansion of a PRG [Peikert's Lecture notes: Section 1.2 on-wards of Lec#5 and Section 1 of Lec#6]
  Lecture 15 (27/9/2017) PRFs from PRGs [Peikert's Lecture notes: Lec#8] No Class on 2/10/2017
  Lecture 16 (4/10/2017) PRFs from PRGs contd. and Symmetric key encryption [Section 3.9 of Pass-shelat]
  Lecture 18 (9/10/2017) Asymmetric encryption, message authentication codes [Sections 3.10, 5.1 and 5.2 of Pass-shelat]
  Lecture 19 Message Authentication Codes [Pass-shelat, Sections 5.1, 5.2]
  Lecture 20 Authenticated encryption, encrypt-then-MAC-paradigm, relations among notions of encryption [Bellare and Namprempre, Asiacrypt 2000 PDF]
  Lecture 21 Digital Signatures [Reyzin, Chapter 9; We didn't see the details of the CRHF construction but it's a recommended read.]
  Lecture 22 Interactive Proofs [Peikert, Chapter 15, pdf]
Student Presentations
  Lecture 23 (1/11/17) IP=PSPACE [ Arora and Barak , Chapter 8] - Nikhil Gupta
  Lecture 24 (12/11/17) IP=PSPACE [Contd. ] - Nikhil Gupta
  Lecture 25 (13/11/17) Hybrid Encryption, El Gammal Encryption, Zero-knowledge proofs [Jon Katz, Lecture no 4 ,and 5 ; Presented by Akanksha Sisodiya, Saurabh D, Keshav P]
  Lecture 26 (15/11/17) Adaptively secure NIZK and public key encryption scheme secure against CCA1 [Jon Katz, Lecture no 6, pdf ; Presented by Sarah Tilscher and Nishat Koti]
  Lecture 27 (17/11/17) CCA1-secure Naor-Yung encryption scheme and CCA2-secure Dolev-Dwork-Naor encryption scheme [Jon Katz, Lecture no 7, pdf ; Presented by Pooja             Kulkarni, Sanket Purandare]
  Lecture 28 (18/11/17) The Dolev-Dwork-Noar encryption scheme [Jon Katz, Lecture no 8, pdf ; Presented by Abhishek Uppar,Janaky Murthy]
  Lecture 29 (20/11/17) Cramer Shoup Encryption Scheme [Jonathan Katz, Lecture no.9, pdf ; Presented by Dara Singh Vohra , Harsh Kara]
  Lecture 30 (22/11/17) The Cramer-Shoup encryption scheme [Jon Katz, Lecture no 10, pdf ; Presented by Rishabh Deshmukh , Aayush Moroney]
  Lecture 31 (24/11/17) Constructing NIZK Proofs [Jon Katz, Lecture no 11, pdf; Presented by Sarvesh and Vinayak]
  Lecture 32 (27/11/17) Constructing NIZK Proofs [Jon Katz, Lecture no 12, pdf and lecture no 13, pdf ; Presented by Amit, Vysaq P R and Abinash Khare]

Recommended Reading:
  Foundations of Cryptography, Volume I-II , Oded Goldreich
  Introduction to Modern Cryptography by Jonathan Katz and Yehuda Lindell
Lecture notes by Leonid Reyzin
Lecture notes by Rafail Pass and Abhi Shelat
Draft Lecture notes by Rafail Ostrovsky

Assignment 1   Due on Monday, August 28th, 5:00PM
Assignment 2   Due on Friday, September 15th, 5:00PM
Assignment 3   Due on Tuesday, October 17th, 11:59P.M. via email.

  Assignment 3 is up!!
This summer (2019) we are organising a reading group on Quantum Cryptography at CSA,IISc. Here is a list of presentations in the reading group.

Sl.No Topic Speaker Reading material
Introduction to Quantum Computation(May 13th) Sruthi Sekar Link
Qubits, Quantum Gates and Measurement(May 30th) OSL Bhavana Lectures 2 and 3 of Ref 2
No Cloning theorem, Quantum teleportation, Deutsch-Josza Algorithm(June 7th) Sruthi Sekar Sections 1.4.3,1.4.4, 1.3.7, 1.3.5 of Ref 1

Useful References:
1. Quantum Computation and Quantum Information by Michael A. Nielsen and Isaac L. Chuang
2. Quantum Cryptography Course by Dominique Unruh

Previously Organised Reading Groups

Secure Computation Reading Group
IISc-IACR School on Cryptology , 4th to 8th January 2018, CSA, IISc Bangalore