Institute: Society for Electronic Transactions and Security (SETS), Chennai

Principal Investigator: Dr. Natarajan Venkatachalam

Co-Principal Investigator: Ms. A Suganya

Quantum key distribution (QKD) is a cryptographic method which enables two or more parties to establish a shared secret key between them. The security of QKD is guaranteed from the fundamental properties of quantum mechanics unlike public-key cryptography whose security depends on difficulty to solve mathematical problems such as factoring, making them insecure against attacks using quantum computers. On the other hand, in QKD, an eavesdropper trying to get some information about the communication needs to measure quantum states, such measurements would only help the intended parties to detect the presence of attackers. Thus, QKD aims to leverage quantum principles to achieve unconditional security against attackers with quantum computer.

Our focus here is on improving the key generation rate as it is preventing QKD from widely-deployed. QKD uses quantum channel only to transmit the predetermined qubits and the rest of the QKD protocol is purely classical and is done in hardware/software. The main bottleneck in making high speed QKD is the post-processing phase that run on a classical channel which is very inefficient when compared to the rate at which raw key is generated from the quantum channel. Thus, the post-processing received much attention in the recent years in order to improve the final QKD key rate. The post-processing process is also known as the key distillation process which consists of key reconciliation and privacy amplification stages. Bi-directional key reconciliation and matrix decomposition techniques will be used for this purpose. In addition, classical approaches followed in conventional cryptographic protocols will be explored and when possible, adapted for improving the efficiency of the chosen QKD protocols.

In this project, our main goal is to develop new and efficient modules for post processing required for fibre-based and free-space QKD systems. In particular, the deliverable is an FPGA-based QKD post-processing system with Authentication module. The post-processing engine will feature modules for parameter estimation, error correction and verification, privacy amplification with side-channel attack resilient implementation. SETS already has an on-going collaboration with IITM in this area.

Key Distillation Engine Experimental Setup on bench before integration with quantum hardware.

Publications from this project: