Key reconciliation in quantum key distribution

Ching‐Nung Yang, Chih-Yueh Tseng, Ming-Chan Lu

Quantum Key Distribution (QKD) could share a secret key between two distant nodes Alice and Bob. In the presence of an eavesdropper and noisy channel, Alice’s key may not be the same as Bob’s key. Thus, QKD protocol has to provide not only the distribution in key agreement phase but also the integrity in key verification phase. Error reconciliation is often used in QKD to share identical keys between Alice and Bob in key verification phase. Recently, Kurt et al. introduce a reconciliation algorithm for QKD (RQKD) to prevent error propagation in some previous reconciliation algorithms. Kurt et al.’s RQKD is a block-wise operation, and uses polynomial interpolation for reconciliation. However, if the x-axis values of polynomials are the same the blocks are removed. In this paper, we propose an enhanced RQKD (ERQKD) to deal with this weakness. When using polynomial-interpolation approach for reconciliation, our ERQKD without deleting block improves the efficiency of sharing qubits.

Masahiro Takeoka

Miralem Mehić, Marcin Niemiec, Harun Šiljak +1 more

Abstract Quantum Key Distribution (QKD) protocols allow the establishment of symmetric cryptographic keys up to a limited distance at limited rates. Due to optical misalignment, noise in quantum detectors, disturbance of the quantum channel or eavesdropping, an error key reconciliation technique is required to eliminate errors. This chapter analyses different key reconciliation techniques with a focus on communication and computing performance. We also briefly describe a new approach to key reconciliation techniques based on artificial neural networks.

Douglas Stebila, Michele Mosca, Norbert Lütkenhaus

Tapster, Gorman, Benton +3 more

Dongjun Park, Donghoe Heo, Suhri Kim +1 more

In this paper, we propose the first single trace side-channel attack on the key reconciliation process for the quantum key distribution (QKD) system. Through a single power consumption trace measured during the syndrome computation of the key reconciliation process on the sender's side, we were able to fully recover the sifted key and the syndrome. The shared secret key between the two users can be directly obtained from the sifted key and the syndrome. The result of our work shows that the QKD system must consider side-channel attacks on the key reconciliation process for its practical use.