On Split-State Quantum Tamper Detection

Title of the Talk: On Split-State Quantum Tamper Detection
Speakers: Naresh Goud Boddu
Host Faculty: Dr.Maria Francis
Date: Jan 21, 2026
Time: 11:30am
Venue: Seminar Hall 1, Department of CSE (CS-004)

Abstract: Tamper-detection codes (TDCs) are fundamental objects at the intersection of cryptography and coding theory. A TDC encodes messages in such a manner that tampering with the codeword causes the decoder to either output the original message or reject it. In this work, we study quantum analogs of one of the most well-studied adversarial tampering models: the so-called t-split-state tampering model, where the codeword is divided into t shares and each share is tampered with locally. It is impossible to achieve tamper detection in the split-state model using classical codewords. Nevertheless, we demonstrate that the situation changes significantly if the message can be encoded into a multipartite quantum state entangled across the t shares. Concretely, we define a family of quantum TDCs on any t ≥ 3 shares, which can detect arbitrary split-state tampering so long as the adversaries are unentangled, or even limited to a finite amount of pre-shared entanglement. Previously, this was only known in the limit of asymptotically large t. As our flagship application, we show how to augment threshold secret sharing schemes with similar tamper-detecting guarantees. We complement our results by establishing connections between quantum TDCs and quantum encryption schemes.

Bio: Naresh Goud Boddu is Vice President and Applied Research Lead at J.P. Morgan Singapore. He completed his Ph.D. in September 2022 under Prof. Rahul Jain at the Centre for Quantum Technologies, National University of Singapore. Following his Ph.D., he was a Postdoctoral Researcher at NTT Research, where he worked with Prof. Vipul Goyal and Prof. Dakshita Khurana until November 2024. At J.P. Morgan, he has worked on lattice-based zero-knowledge proofs applications for financial institutions. His research interests lie at the intersection of post-quantum cryptography, quantum cryptography, and quantum information.