Research

My primary research interest is the provable security analysis of symmetric-key cryptographic modes using combinatorial techniques. My doctoral research focused on provable security against a classical adversary. At Inria, I started exploring the exciting new field of provable security against a quantum adversary, as part of the ERC project QUASYModo. At present I am studying proof frameworks for adapting classical counting techniques in post-quantum security proofs.

My complete academic CV (last updated in July 2026) can be found here: [PDF] link to CV. My publications are also listed on my DBLP page.

Publications

The Key Control Security of KDF Combiners.
SCN '26 (to appear). ePrint

Pencil: A Domain-Extended Committing BBB PRF for Strengthening GCM.
Crypto '26 (to appear). ePrint
(with Jean Paul Degabriele and Chandranan Dhar)

How to Build a Short-Input Random Oracle from Public Random Permutations.
Eurocrypt '26. DOI ePrint
(with Nilanjan Datta, Avijit Dutta, Ashwin Jha, Sougata Mandal, Bart Mennink, Hrithik Nandi and Yaobin Shen)

Breaking and Fixing Macakey.
Transactions on Symmetric Cryptology 2026(1). DOI ePrint
(with Bishwajit Chakraborty and Chandranan Dhar)

Post-quantum Security of Key-Alternating Feistel Ciphers.
Asiacrypt '25. DOI ePrint
(with Jyotirmoy Basak, Amit Kumar Chauhan, Ravindra Jejurikar, Ashwin Jha, Anandarup Roy, André Schrottenloher and Suprita Talnikar)

Cryptographic Treatment of Key Control Security In Light of NIST SP 800-108.
Crypto '25. DOI ePrint
(with Avijit Dutta, Akiko Inoue, Tetsu Iwata, Ashwin Jha, Kazuhiko Minematsu, Mridul Nandi, Yu Sasaki, Meltem Sönmez Turan and Stefano Tessaro)

Building a BBB Pseudorandom Permutation using Lai-Massey Networks.
Communications in Cryptology 1(4). DOI ePrint
(with Mohammad Amin Raeisi)

Block Cipher Doubling for a Post-Quantum World.
Communications in Cryptology 1(3). DOI ePrint
(with André Chailloux, Paul Frixons, Bart Mennink and María Naya-Plasencia)

Mind the Bad Norms: Revisiting Compressed Oracle-based Quantum Indistinguishability Proofs.
Asiacrypt '24. DOI ePrint
(with Benoît Cogliati, Jordan Ethan and Ashwin Jha)

Efficient Variants of TNT with BBB Security.
ProvSec '24. DOI ePrint
(with Bishwajit Chakraborty, Wonseok Choi, Avijit Dutta, Cuauhtemoc Mancillas López, Hrithik Nandi and Yaobin Shen)

Indifferentiability of 3-Round Confusion-Diffusion Networks.
SCN '24. DOI
(with Mridul Nandi, Sayantan Paul and Abishanka Saha)

Provably Secure Online Authenticated Encryption and Bidirectional Online Channels.
SAC '24. DOI ePrint
(with Arghya Bhattacharjee, Daniel Collins and Mridul Nandi)

The Committing Security of MACs with Applications to Generic Composition.
Crypto '24. DOI ePrint
(with Bishwajit Chakraborty, Wonseok Choi, Avijit Dutta, Jérôme Govinden and Yaobin Shen)

On Quantum-Secure Compressing Pseudorandom Functions.
Asiacrypt '23. DOI ePrint
(with Benoît Cogliati, Jordan Ethan and Ashwin Jha)

BBB-Security for 5-Round Even-Mansour-Based Key-Alternating Feistel Ciphers.
Designs, Codes and Cryptography 92(1). DOI
(with Arghya Bhattacharjee, Avijit Dutta, Mridul Nandi and Anik Raychaudhuri)

PAE: Towards More Efficient and BBB-secure AE From a Single Public Permutation.
ICICS '23. DOI ePrint
(with Arghya Bhattacharjee, Avijit Dutta and Eik List)

Revisiting the Indifferentiability of the Sum of Permutations.
Crypto '23. DOI ePrint
(with Aldo Gunsing, Ashwin Jha, Bart Mennink and Yaobin Shen)

Offset-Based BBB-Secure Tweakable Block-ciphers with Updatable Caches.
Indocrypt '22. DOI ePrint
(with Arghya Bhattacharjee and Mridul Nandi)

A Sponge-Based PRF with Good Multi-user Security.
SAC '22. DOI ePrint
(with Arghya Bhattacharjee and Mridul Nandi)

Improved indifferentiability security proof for 3-round tweakable Luby-Rackoff.
Designs, Codes and Cryptography 89(10). DOI
(with Mridul Nandi and Anik Raychaudhuri)

QCB: Efficient Quantum-Secure Authenticated Encryption.
Asiacrypt '21. DOI ePrint
(with Xavier Bonnetain, André Chailloux, Gaëtan Leurent, María Naya-Plasencia, André Schrottenloher and Yannick Seurin)

ZCZ - Achieving n-bit SPRP Security with a Minimal Number of Tweakable-Block-Cipher Calls.
Asiacrypt '18. DOI ePrint
(with Eik List and Mridul Nandi)

Turning Online Ciphers Off.
Transactions on Symmetric Cryptology 2017(2). DOI ePrint
(with Elena Andreeva, Guy Barwell, Daniel Page, Mridul Nandi and Martijn Stam)

Improved Security for OCB3.
Asiacrypt '17. DOI ePrint
(with Mridul Nandi)

The Iterated Random Function Problem.
Asiacrypt '17. DOI ePrint
(with Nilanjan Datta, Avijit Dutta, Nicky Mouha and Mridul Nandi)

OleF: an Inverse-Free Online Cipher.
Transactions on Symmetric Cryptology 2016(2). DOI ePrint
(with Mridul Nandi)

An Inverse-Free Single-Keyed Tweakable Enciphering Scheme.
Asiacrypt '15. DOI ePrint
(with Mridul Nandi)

Notes and Preprints

A Note on Feedback-PRF Mode of KDF from NIST SP 800-108.
(with Avijit Dutta, Tetsu Iwata, Ashwin Jha, Kazuhiko Minematsu, Mridul Nandi, Yu Sasaki, Meltem Sönmez Turan and Stefano Tessaro) ePrint

BBB Secure Large-Tweak TBC from Ideal Block Ciphers.
(with Arghya Bhattacharjee, Nilanjan Datta, Avijit Dutta, Shibam Ghosh and Sougata Mandal) ePrint

Universal Context Commitment without Ciphertext Expansion.
(with Arghya Bhattacharjee and Chandranan Dhar) ePrint

Indifferentiability of 6-round Feistel.
(with Ashwin Jha, Mridul Nandi, Sayantan Paul and Abishanka Saha)

My primary research interest is the provable security analysis of symmetric-key cryptographic modes using combinatorial techniques. My doctoral research focused on provable security against a classical adversary. At Inria, I started exploring the exciting new field of provable security against a quantum adversary, as part of the ERC project QUASYModo. At present I am studying proof frameworks for adapting classical counting techniques in post-quantum security proofs.

My complete academic CV (last updated in July 2026) can be found here: [PDF] link to CV. My publications are also listed on my DBLP page.