Sougata Mandal

Senior Research Fellow, IAI – TCG CREST

Research Interests

My research interest lies in Symmetric Key Cryptography. To be precise, my thesis is primarily based on the following areas in Symmetric Key Cryptography:

Provable Security: This includes designing BBB secure large-tweak tweakable blocks, tweakable fork-ciphers from ideal Block-ciphers and analyzing Committing security of various MAC and Authenticated Encryption modes.
Leakage Resilient Cryptography: This includes design and analysis of leakage resilient authenticated ciphers.

In addition, I am currently exploring the area of quantum provable security.

Education and Background

M.Tech Cryptology and Security at Indian Statistical Institute, Kolkata
M.Sc in Pure Mathematics from University of Calcutta
B.Sc in Mathematics from University of Calcutta

Academic Activities and Achievements

Delivered an Invited research talk at the 2nd Kolkata Crypto Day (Jan, 2026).
Awarded a travel grant worth €1,600 by the International Association for Cryptologic Research (IACR) to present the paper “Context-Committing Security of Leveled Leakage-Resilient AEAD” at FSE 2025 held in Rome.
Done a 3-month (Aug – Oct, 2024) research internship at Ruhr University, Bochum, Germany, under the supervision of Prof. Gregor Leander. Complete travel and local support were provided by the host University.
Invited at ASK 2026, GAPS 2025, ASK 2024, ASK 2023.
Had a single-author paper “Tweakable ForkCipher from Ideal Block Cipher” at IACR Communications in Cryptology, 2024.
Subreviewer at ToSC 2025, ASIACRYPT 2024.

Publications

Nilanjan Datta, Avijit Dutta, Sougata Mandal, Hrithik Nandi, Amlan Sinha: Post-Quantum Security of Keyed Sum of Permutations and Its Siblings. IACR ASIACRYPT 2026.
S. Pal, S. Kar, S. Ghosh, S. Chakraborty, K. D. Ghosh, Amlan Sinha, Sougata Mandal, D. Katiyar: Universally Composable Reverse Firewalls for Oblivious Linear Evaluation and Applications. IACR ASIACRYPT 2026.
Ritam Bhaumik, Nilanjan Datta, Avijit Dutta, Ashwin Jha, Sougata Mandal, Bart Mennink, Hrithik Nandi, Yaobin Shen: How to Build a Short-Input Random Oracle from Public Random Permutations, EUROCRYPT 2026.
Nilanjan Datta, Avijit Dutta, Sougata Mandal and Hrithik Nandi: Indifferentiability of STH, EDM and EDMD. IACR Communications in Cryptology, Vol: 2, Issue: 2 (2025). [Link]
C. Dhar, J. Ethan, R. Jejurikar, M. Khairallah, E. List, Sougata Mandal: Context Committing Security of Levelled Leakage-Resilient AEAD. IACR Transaction on Symmetric Cryptology (ToSC 2024). [Link]
Sougata Mandal, Tweakable ForkCipher from Ideal Block Cipher, IACR Communications in Cryptology, Volume 1, Issue 3: 42, 2024. [Link]
Nilanjan Datta, Avijit Dutta, Eik List, Sougata Mandal, FEDT: Forkcipher Based Leakage Resilient AE, IACR Communications in Cryptology, Volume 1, Issue 2 (2024). [Link]
Nilanjan Datta, Shreya Dey, Avijit Dutta, Sougata Mandal: Cascading Four Round LRW1 is Beyond Birthday Bound Secure. IACR Transactions of Symmetric Cryptology (ToSC 2023). [Link]
Nilanjan Datta, Avijit Dutta, Eik List, Sougata Mandal: On the Security of Triplex- and Multiplex-type Constructions with Smaller Tweaks. INDOCRYPT 2023. [Link]

PrePrints

Avik Chakraborti, Bishwajit Chakraborty, Nilanjan Datta, Avijit Dutta, Ashwin Jha, Sougata Mandal, Hrithik Nandi, Mridul Nandi, Abishanka Saha: Naor-Reingold goes Beyond-the-Birthday-Bound. IACR Cryptol. ePrint Arch. 2025: 1486 (2025). [Link]
Arghya Bhattacharjee, Ritam Bhaumik, Nilanjan Datta, Avijit Dutta, Sougata Mandal: BBB Secure Arbitrary Length Tweak TBC from n-bit Block Ciphers. IACR Cryptol. ePrint Arch. 2024: 2049 (2024). [Link]