Hardware Implementation of a Stealthy and Lightweight Backdoor for CRYSTALS-Kyber in Hybrid Cryptosystems

Speaker

Dr. Debapriya Basu Roy

Assistant Professor with the Department of Computer Science and Engineering, Indian Institute of Technology Kanpur.
PhD degree from IIT Kharagpur and was a post-doctoral fellow with the Technical University of Munich

Title

"Hardware Implementation of a Stealthy and Lightweight Backdoor for CRYSTALS-Kyber in Hybrid Cryptosystems "

Abstract

The threat of practical quantum attacks has catapulted viable alternatives like Post-Quantum Cryptography (PQC) into prominence. The adoption and integration of standardized PQC primitives across the entire digital stack are promoted by various standardization bodies, governments, and major corporate houses. A serious challenge in quantum migration is to ensure that there is no hidden backdoor in the PQC implementations of a hybrid cryptosystem (support for both pre-quantum and post-quantum algorithms), which are often procured from a third-party vendor. In this presentation, we investigate the possibility of a Kleptographic backdoor on the NIST-recommended key-encapsulation mechanism CRYSTALS-Kyber. The modified Kyber Key-Generation algorithm achieves indistinguishable decryption failure probability compared to the original CRYSTALS-Kyber. The Kleptographic module is also implemented in FPGA, embedded inside the CRYSTALS-Kyber accelerator with a very low area overhead (283 LUTs or 2% of total area), and thus can easily pass performance and functionality tests.



 

About Speaker

Dr. Debapriya Basu Roy received his PhD degree from IIT Kharagpur and was a post-doctoral fellow with the Technical University of Munich. He is currently an Assistant Professor with the Department of Computer Science and Engineering, Indian Institute of Technology Kanpur. His research interests include applied cryptography, hardware security, post-quantum cryptography, side channel analysis and digital VLSI. Some of his notable contributions in the domain of hardware security are efficient implementation of elliptic curve cryptography, side-channel leakage quantification and implementation of post-quantum cryptography on FPGAs.