Current Projects

We investigate hash-based signatures that use only hash functions. These schemes are post-quantum and will remain secure against an adversary with access to a quantum computer. 

We study message transmission and secret key agreement protocols that are information-theoretically secure based on physical layer assumptions. As long as physical layer requirements hold during the execution, these protocols are secure against any adversary with unlimited computational power.

We attempt to develop a system that ensures secure access and long-term data storage. Our objective is to achieve information-theoretic confidentiality for data both in transit and at rest.

All the cryptographic schemes based on number-theoretic assumptions will be insecure with the advent of a quantum computer. We investigate various forms of cryptography that are quantum-secure. This includes lattice-based cryptography and hash-based cryptography. 

We investigate leakage-resilient secret sharing where a computationally unbounded adversary can get arbitrary leakage information from the shares of all the parties. The only restriction put on the adversary is -- it only gets a bounded number of bits as leakage. We investigate the issue of correct recovery of secret (a.k.a robustness) even when  a leaking adversary tampers with some of the shares. 

A Proof-of-Location (POL) system is used to issue a token (pol) to a user, who can use it to attest their presence at a location to a verifier at a later time. We aim for a globally accessible POL scheme facilitating offline verifiability of pol, implemented using blockchain.

Behavioral Authentication (BA) systems use user behavioral data for authentication. We proposed Draw A Circle (DAC) as a challenge-response based BA system and measured the information in DAC. We also investigated the scalability of BA system, BA system in cryptographic authentication, and security and privacy of BA system.

We investigate designing and implementing resource sharing scheme within smart neighbourhood.  The proposed scheme uses permissioned blockchain as a public platform where the users of this system can advertise as well as share their resources. We also conduct security and privacy analysis of this scheme and explore cryptographic primitives to achieve the system privacy and security requirement.

Blockchain is a distributed digital ledger to record transactions. It offers decentralization, anonymity, transparency, and immutability. Popular applications of blockchain include cryptocurrencies such as Bitcoin and Ethereum, and decentralized applications using smart contracts. We investigate how smart contracts can be used in applications such as outsourcing computation by eliminating the need for a trusted third party

We study the design, analysis, and implementation of practical verifiable computation schemes. Verifiable computation enables a thin client to outsource a computationally intensive task to more powerful but untrusted servers, and verify the correctness of the result efficiently. These schemes allow users to minimize their investments in computing infrastructure.

In this project, we focus on quantum security for data plane of SDNs. We consider a variety of techniques, such as secret sharing and multipath routing, to enhance secrecy. Particularly, we investigate how techniques with information theoretic security are vulnerable in real network. Both theoretical and experimental aspects are considered. 

Facilitating the appropriate access to data in large, open, distributed systems such as the Web and Internet-of-Things (IoT) is a problem that plagues many organizations. We develop a token-based access control system that provides efficient and refined (conditional) access to resources in such systems