Dr. Souradyuti Paul

Associate Professor

Computer Science and Engineering

Indian Institute of Technology Bhilai

email: souradyuti[at]iitbhilai.ac.in

Brief Introduction

Dr. Souradyuti Paul is presently working as an associate professor in the department of EECS of IIT Bhilai. Earlier, he used to be an assistant professor of CSE at IIT Gandhinagar (2014-17). He obtained his BE, MTech and PhD degrees from Jadavpur University (1994 - 98), Indian Statistical Institute (1999 - 01) and KU Leuven (2001 - 06), respectively. He spent several years as a postdoctoral (or guest) researcher at KU Leuven (2006 - 08), NIST, USA (2008 - 12) and University of Waterloo (2012 - 14).

Since 2001, Dr. Paul’s research interests have always centered on cryptography and related areas.  His present research interests includeCryptographic modes and Multiparty protocols, Blockchain and Cryptocurrencies, Anonymity and Privacy, and Network Security. Earlier, he used to work in Design and analysis of cryptographic primitives (e.g. stream cipher, hash function, etc.).

While working at NIST, USA (2008-12), Dr. Paul has participated in the evaluation and selection of the US Govt. hash function standard SHA-3 (Secure Hash Algorithm 3). In 2014, he was awarded the Excellence in Research Fellowship at IIT Gandhinagar. He was a recipient of Indian National Mathematical Olympiad (INMO) awardee in 1992.


Lottery on the Internet: A Fairy Tale?: Lottery is one of the most well-known use-cases of multiparty protocols. However much excitement and thrill that the very term “lottery” may generate, designing a secure lottery protocol on the Internet is a challenging task. The reason is simple: the Internet is treacherous waters, and anyone in it is a potential attacker!

The good news is that some of the potential cheating-of-money scenariosassociated with the lottery protocol have been addressed adequately in the literature in the last two decades, and that they were subsequently eliminated to some satisfaction. The magic happened due to the various state-of-the-art advancements in the field of cryptography, such as inventions of signature schemes and their many variants, collision-resistant hash functions, secret-sharing schemes, etc.

Notwithstanding the above good news on protection against the stealing of money, no Internet-based lottery protocol has yet been implemented having an important property known as fairness (which has nothing to do with the stealing of money), impeding the widespread adoption of it by the users. Thefairness property of a lottery protocol and its variants prevent the system from aborting by the dishonest parties, and thereby, denying the honest parties their legitimate dues.

In this talk I shall discuss various fairness issues that are applicable in a general multiparty setting, and how they can potentially be included in a protocol using the various advantages offered by the recent Blockchain technology.