Ashrujit Ghoshal

I am a Postdoctoral Fellow at Carnegie Mellon University advised by Elaine Shi. I recently received my PhD in Computer Science from the University of Washington, advised by Stefano Tessaro and Rachel Lin. I spent the summers of 2021 and 2022 as a research intern at NTT Research working with Ilan Komargodski. My current research interests lie mainly in the theory and foundations of cryptography.

Even earlier, I graduated from the Indian Institute of Technology, Kharagpur in July 2018 with a Bachelor of Technology (Hons.) in Computer Science and Engineering. I was advised by Debdeep Mukhopadhyay for my undergraduate thesis.

Publications and Manuscripts

Efficient Pre-processing PIR Without Public-Key Cryptography [eprint]
Ashrujit Ghoshal, Mingxun Zhou, Elaine Shi
Preprint

The Query-Complexity of Preprocessing Attacks [eprint] [doi] [talk] [slides]
Ashrujit Ghoshal, Stefano Tessaro
CRYPTO 2023

Optimal Security for Keyed Hash Functions: Avoiding Time-Space Tradeoffs for Finding Collisions [eprint] [doi] [slides]
Cody Freitag, Ashrujit Ghoshal, Ilan Komargodski
EUROCRYPT 2023

Time-Space Tradeoffs for Sponge Hashing: Attacks and Limitations for Short Collisions [eprint] [doi] [talk] [slides]
Cody Freitag, Ashrujit Ghoshal, Ilan Komargodski
CRYPTO 2022

On Time-Space Tradeoffs for Bounded-Length Collisions in Merkle-Damgård Hashing [eprint] [doi] [talk] [slides]
Ashrujit Ghoshal, Ilan Komargodski
CRYPTO 2022

Hiding in Plain Sight: Memory-tight Proofs via Randomness Programming [eprint] [doi] [talk] [slides]
Ashrujit Ghoshal, Riddhi Ghosal, Joseph Jaeger, Stefano Tessaro
EUROCRYPT 2022

Tight State-Restoration Soundness in the Algebraic Group Model [eprint] [doi] [talk] [slides]
Ashrujit Ghoshal and Stefano Tessaro
CRYPTO 2021

The Memory-Tightness of Authenticated Encryption [eprint] [doi] [talk] [slides]
Ashrujit Ghoshal, Joseph Jaeger, Stefano Tessaro
CRYPTO 2020

On the Memory-Tightness of Hashed ElGamal [eprint] [doi] [talk] [slides]
Ashrujit Ghoshal and Stefano Tessaro
EUROCRYPT 2020

Lightweight and Side-channel Secure 4 × 4 S-Boxes from Cellular Automata Rules [eprint] [doi]
Ashrujit Ghoshal, Rajat Sadhukhan, Sikhar Patranabis, Nilanjan Datta, Stjepan Picek, Debdeep Mukhopadhyay
IACR Transactions on Symmetric Cryptology, 2018(3) and FSE 2019

Template-Based Fault Injection Analysis of Block Ciphers [eprint] [doi]
Ashrujit Ghoshal, Sikhar Patranabis, Debdeep Mukhopadhyay
SPACE 2018

Several Masked Implementations of the Boyar-Peralta AES S-Box [eprint] [doi]
Ashrujit Ghoshal and Thomas De Cnudde
INDOCRYPT 2017

An Evaluation of Lightweight Block Ciphers for Resource-Constrained Applications: Area, Performance, and Security [doi]
Rajat Sadhukhan, Sikhar Patranabis, Ashrujit Ghoshal, Debdeep Mukhopadhyay, Vishal Saraswat, Santosh Ghosh
Journal of Hardware and Systems Security 2017

Other

Implementation Attacks on Block Ciphers: New Approaches and Countermeasures [pdf]
Bachelors Thesis