Sumit Debnath

National Institute of Technology, Jamshedpur | NIT Jamshedpur · Department of Mathematics

We prove both theoretically and experimentally that the scheme (Wang et al. [7], 2011) can be broken in polynomial time even for rings of small size.

It has been forty years since the TCP/IP protocol blueprint, which is the core of the modern worldwide Internet, was published. Over this long period, technology has made rapid progress. These advancements are slowly putting pressure and new demands on the underlying network architecture design. Therefore, there was a need for innovations that coul...

The Internet of Things (IoT)-enabled ride sharing is one of the most transforming and innovative technologies in the transportation industry. It has myriads of advantages, but with increasing demands there are security concerns as well. Traditionally, cryptographic methods are used to address the security and privacy concerns in a ride sharing syst...

The deployed vehicles in an Internet of Vehicles (IoV) can take intelligent decisions by means of exchanging the real-time traffic-related information between the vehicles and IoV infrastructures. This further reduces the probability of the traffic jams and accidents. However, the insecure (public) communication among the various entities in IoV ma...

Signcryption is an important cryptographic scheme which is used for both confidentiality and unforgeability. It has many interesting practical applications. Enormous growth of quantum computers makes a warning to the existing classical signcryption schemes due to Shor’s algorithm. As a result, designing signcryption schemes, which can withstand qua...

Over the last few years, Internet of Medical Things (IoMT) has completely transformed the healthcare industry. It is bringing out the most notable, and unprecedented impacts on human health, and has totally changed the way we look at the healthcare industry. The healthcare sector all around the globe are leapfrogging, and adopting the technology, h...

Contact tracing has emerged as a powerful and effective measure to curb the spread of contagious diseases. It is a robust tool, but on the downside, it possesses a risk of privacy violations as contact tracing requires gathering a lot of personal information. So there is a need for a cryptographic primitive that obfuscate the personal data of the u...

Over the last two decades, the field of multivariate public key cryptography (MPKC) has seen tremendous growth and a rich influx of novel ideas. Gradually, MPKC has emerged as a top candidate for the construction of new generation of algorithms that provides resistance to attacks by quantum algorithms. In 2020, Duong et al. [8] put forth a new mult...

Functional encryption (FE) is an exciting new public key paradigm that provides solutions to most of the security challenges of cloud computing in a non-interactive manner. In the context of FE, inner product functional encryption (IPFE) is a widely useful cryptographic primitive. It enables a user with secret key \(usk_\mathbf {y}\) associated to...

Group signatures are significant primitive for anonymity, which allow group members to sign messages while hiding in the group, however, the signers remain accountable. Most of the existing schemes on group signature are relying on traditional cryptographic primitives, whereas rapid advancements in quantum computing suggest an originating threat to...

In many realistic scenarios, participants wish to perform some secret set operations such as intersection, union, cardinality of intersection, etc. on their private data sets. Private Set Intersection (PSI) plays a major role in addressing such problems. PSI is one of the widely used secure multi-party computation technique that allows the particip...

In the context of secure multi-party computation, private set intersection (PSI) is an important cryptographic primitive for performing joint operations on datasets in a privacy preserving manner. In particular, it allows the participants to privately determine the intersection of their private datasets. Most of the existing PSI protocols are based...

This book consists of refereed selected papers from the International Conference on Security & Privacy – ICSP 2020. The book is focused on the state-of-the-art developments of network security, secure cryptographic protocols, post-quantum cryptography, quantum cryptography, block-chain and cryptocurrency, IoT security and privacy, cloud security, m...

This book constitutes the refereed proceedings of the Second International Conference, ICSP 2021, held in Jamshedpur, India, in November 2021. The 10 full papers were carefully reviewed and selected from 44 submissions. The contributions are organized in the following blocks: Cryptanalysis and other attacks; Symmetric cryptography and hash functio...

When Kevin Ashton proposed the catchword 'Internet of Things' in 1999, little did he know that technology will become an indispensable part of human lives in just two decades. In short, the Internet of Things (IoT), is a catch-all terminology used to describe devices connected to the internet. These devices can share and receive data as well as pro...

Oblivious transfer (OT) is a fundamental cryptographic primitive. It is developed for the efficient and feasible implementation of most advanced cryptographic tasks. Today, most of the existing OT protocols’ security is based on number-theoretic assumptions. However, many number-theoretical problems are solvable by a quantum computer in polynomial...

Nowadays, the necessity of electronic information increases rapidly. As a consequence, often, that information needs to be shared among mutually distrustful parties. In this area, private set intersection (PSI) and its variants play an important role when the participants wish to do secret operations on their input sets. Unlike the most modern publ...

Today, with the advent of internet technology, we are looking for e-mechanisms such as e-voting, e-commerce, e-learning, etc., where electronic information are transferred between the entities via the public network. However, e-mechanisms require the support of integrity, authenticity and non-repudiability of the transmitted electronic information....

Electronic information is increasingly shared among unreliable entities. In this context, one interesting problem involves two parties that secretly want to determine an intersection of their respective private data sets while none of them wish to disclose the whole set to the other. One can adopt a Private Set Intersection (PSI) protocol to addres...

PSI and its variants play a major role when the participants want to perform secret operations on their private data sets. The importance of this chapter is twofold. In the first phase, the author presents a size-hiding PSI-CA protocol followed by its authorized variant, APSI-CA, utilizing Bloom filter. All these constructions are proven to be secu...

The availability of electronic information is necessary in our everyday life. Progressively, often, data needs to be shared among the unreliable entities. In this field, one interesting and common problem occurs when two parties want to secretly determine the intersection or cardinality of intersection of their respective private sets. PSI or its v...

Private Set Intersection (PSI) is a useful cryptographic primitive for developing practical privacy preserving techniques for Big Data. PSI allows entities to securely extract intersection of the large data sets they own, without revealing any other crucial information for their input sets. Fairness is a critical issue for both mutual Private Set I...

This paper presents the first PSI protocol that achieves constant (O(1)) communication complexity with linear computation overhead and is fast even for the case of large input sets. The scheme is proven to be provably secure in the standard model against semi-honest parties. We combine somewhere statistically binding (SSB) hash function with indist...

In this paper, we propose a two-way oblivious pseudorandom function (mOPRF) secure in standard model against malicious parties under the decisional composite residuosity and decisional Diffie–Hellman assumptions. Using this two-way OPRF, we construct an optimistic mutual private set intersection (PSI) protocol conserving fairness. In our PSI protoc...

In this paper, we study Private Set Intersection Cardinality (PSI-CA) protocols and propose two new constructions of PSI-CA. While one of these constructions is secure in the standard model, the other one is secure in the random oracle model (ROM). The security is under the Decisional Diffie-Hellman (DDH) assumption against malicious adversaries. O...

We first present a Private Set Intersection Cardinality (PSI-CA) protocol followed by its authorized variant, APSI-CA, utilizing Bloom filter (\(\mathsf{BF}\)). We further extend these to PSI and APSI protocols. All the constructions are proven to be secure in standard model with linear complexities. Moreover, our protocols hide the size of the cli...

We present a two-way Oblivious Pseudorandom Function (\(\mathsf{mOPRF}\)) secure in the malicious model under the Decisional Composite Residuosity (DCR) and Decisional Diffie-Hellman (DDH) assumptions. Using this \(\mathsf{mOPRF}\), we construct an optimistic mutual Private Set Intersection (\(\mathsf{mPSI}\)) protocol preserving fairness. Unlike e...