scholarly journals High throughput error correction in information reconciliation for semiconductor superlattice secure key distribution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianguo Xie ◽  
Han Wu ◽  
Chao Xia ◽  
Peng Ding ◽  
Helun Song ◽  
...  

AbstractSemiconductor superlattice secure key distribution (SSL-SKD) has been experimentally demonstrated to be a novel scheme to generate and agree on the identical key in unconditional security just by public channel. The error correction in the information reconciliation procedure is introduced to eliminate the inevitable differences of analog systems in SSL-SKD. Nevertheless, the error correction has been proved to be the performance bottleneck of information reconciliation for high computational complexity. Hence, it determines the final secure key throughput of SSL-SKD. In this paper, different frequently-used error correction codes, including BCH codes, LDPC codes, and Polar codes, are optimized separately to raise the performance, making them usable in practice. Firstly, we perform multi-threading to support multi-codeword decoding for BCH codes and Polar codes and updated value calculation for LDPC codes. Additionally, we construct lookup tables to reduce redundant calculations, such as logarithmic table and antilogarithmic table for finite field computation. Our experimental results reveal that our proposed optimization methods can significantly promote the efficiency of SSL-SKD, and three error correction codes can reach the throughput of Mbps and provide a minimum secure key rate of 99%.

2018 ◽  
Vol 18 (9&10) ◽  
pp. 795-813
Author(s):  
Sunghoon Lee ◽  
Jooyoun Park ◽  
Jun Heo

Quantum key distribution (QKD) is a cryptographic system that generates an information-theoretically secure key shared by two legitimate parties. QKD consists of two parts: quantum and classical. The latter is referred to as classical post-processing (CPP). Information reconciliation is a part of CPP in which parties are given correlated variables and attempt to eliminate the discrepancies between them while disclosing a minimum amount of information. The elegant reconciliation protocol known as \emph{Cascade} was developed specifically for QKD in 1992 and has become the de-facto standard for all QKD implementations. However, the protocol is highly interactive. Thus, other protocols based on linear block codes such as Hamming codes, low-density parity-check (LDPC) codes, and polar codes have been researched. In particular, reconciliation using LDPC codes has been mainly studied because of its outstanding performance. Nevertheless, with small block size, the bit error rate performance of polar codes under successive-cancellation list (SCL) decoding with a cyclic redundancy check (CRC) is comparable to state-of-the-art turbo and LDPC codes. In this study, we demonstrate the use of polar codes to improve the performance of information reconciliation in a QKD system with small block size. The best decoder for polar codes, a CRC-aided SCL decoder, requires CRC-precoded messages. However, messages that are sifted keys in QKD are obtained arbitrarily as a result of a characteristic of the QKD protocol and cannot be CRC-precoded. We propose a method that allows arbitrarily obtained sifted keys to be CRC precoded by introducing a virtual string. Thus the best decoder can be used for reconciliation using polar codes and improves the efficiency of the protocol.


2015 ◽  
pp. 419-434
Author(s):  
Thomas Brochmann Pedersen ◽  
Mustafa Toyran

It is widely accepted in the quantum cryptography community that interactive information reconciliation protocols, such as cascade, are inefficient due to the communication overhead. Instead, non-interactive information reconciliation protocols based on i.e. LDPC codes or, more recently, polar codes have been proposed. In this work, we argue that interactive protocols should be taken into consideration in modern quantum key distribution systems. In particular, we demonstrate how to improve the performance of cascade by proper implementation and use. Our implementation of cascade reaches a throughput above 80 Mbps under realistic conditions. This is more than twice the throughput previously demonstrated in any information reconciliation protocol.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kadir Gümüş ◽  
Tobias A. Eriksson ◽  
Masahiro Takeoka ◽  
Mikio Fujiwara ◽  
Masahide Sasaki ◽  
...  

AbstractReconciliation is a key element of continuous-variable quantum key distribution (CV-QKD) protocols, affecting both the complexity and performance of the entire system. During the reconciliation protocol, error correction is typically performed using low-density parity-check (LDPC) codes with a single decoding attempt. In this paper, we propose a modification to a conventional reconciliation protocol used in four-state protocol CV-QKD systems called the multiple decoding attempts (MDA) protocol. MDA uses multiple decoding attempts with LDPC codes, each attempt having fewer decoding iteration than the conventional protocol. Between each decoding attempt we propose to reveal information bits, which effectively lowers the code rate. MDA is shown to outperform the conventional protocol in regards to the secret key rate (SKR). A 10% decrease in frame error rate and an 8.5% increase in SKR are reported in this paper. A simple early termination for the LDPC decoder is also proposed and implemented. With early termination, MDA has decoding complexity similar to the conventional protocol while having an improved SKR.


2017 ◽  
Vol 19 (2) ◽  
pp. 023003 ◽  
Author(s):  
Sarah J Johnson ◽  
Andrew M Lance ◽  
Lawrence Ong ◽  
Mahyar Shirvanimoghaddam ◽  
T C Ralph ◽  
...  

Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1087 ◽  
Author(s):  
Kun Zhang ◽  
Xue-Qin Jiang ◽  
Yan Feng ◽  
Runhe Qiu ◽  
Enjian Bai

Due to the rapid development of quantum computing technology, encryption systems based on computational complexity are facing serious threats. Based on the fundamental theorem of quantum mechanics, continuous-variable quantum key distribution (CVQKD) has the property of physical absolute security and can effectively overcome the dependence of the current encryption system on the computational complexity. In this paper, we construct the spatially coupled (SC)-low-density parity-check (LDPC) codes and quasi-cyclic (QC)-LDPC codes by adopting the parity-check matrices of LDPC codes in the Advanced Television Systems Committee (ATSC) 3.0 standard as base matrices and introduce these codes for information reconciliation in the CVQKD system in order to improve the performance of reconciliation efficiency, and then make further improvements to final secret key rate and transmission distance. Simulation results show that the proposed LDPC codes can achieve reconciliation efficiency of higher than 0.96. Moreover, we can obtain a high final secret key rate and a long transmission distance through using our proposed LDPC codes for information reconciliation.


Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2152
Author(s):  
Karim El-Abbasy ◽  
Ramy Taki Eldin ◽  
Salwa El Ramly ◽  
Bassant Abdelhamid

Polar codes are featured by their low encoding/decoding complexity for symmetric binary input-discrete memoryless channels. Recently, flexible generic Successive Cancellation List (SCL) decoders for polar codes were proposed to provide different throughput, latency, and decoding performances. In this paper, we propose to use polar codes with flexible fast-adaptive SCL decoders in Digital Video Broadcasting (DVB) systems to meet the growing demand for more bitrates. In addition, they can provide more interactive services with less latency and more throughput. First, we start with the construction of polar codes and propose a new mathematical relation to get the optimized design point for the polar code. We prove that our optimized design point is too close to the one that achieves minimum Bit Error Rate (BER). Then, we compare the performance of polar and Low-Density Parity Check (LDPC) codes in terms of BER, encoder/decoder latencies, and throughput. The results show that both channel coding techniques have comparable BER. However, polar codes are superior to LDPC in terms of decoding latency, and system throughput. Finally, we present the possible performance enhancement of DVB systems in terms of decoding latency and complexity when using optimized polar codes as a Forward Error Correction (FEC) technique instead of Bose Chaudhuri Hocquenghem (BCH) and LDPC codes that are currently adopted in DVB standards.


2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Bang-Ying Tang ◽  
Bo Liu ◽  
Wan-Rong Yu ◽  
Chun-Qing Wu

AbstractInformation reconciliation (IR) corrects the errors in sifted keys and ensures the correctness of quantum key distribution (QKD) systems. Polar codes-based IR schemes can achieve high reconciliation efficiency; however, the incidental high frame error rate decreases the secure key rate of QKD systems. In this article, we propose a Shannon-limit approached (SLA) IR scheme, which mainly contains two phases: the forward reconciliation phase and the acknowledgment reconciliation phase. In the forward reconciliation phase, the sifted key is divided into sub-blocks and performed with the improved block checked successive cancellation list decoder of polar codes. Afterward, only the failure corrected sub-blocks perform the additional acknowledgment reconciliation phase, which decreases the frame error rate of the SLA IR scheme. The experimental results show that the overall failure probability of SLA IR scheme is decreased to $$10^{-8}$$ 10 - 8 and the efficiency is improved to 1.091 with the IR block length of 128 Mb. Furthermore, the efficiency of the proposed SLA IR scheme is 1.055, approached to Shannon limit, when the quantum bit error rate is 0.02 and the input scale of 1 Gb, which is hundred times larger than the state-of-the-art implemented polar codes-based IR schemes.


2021 ◽  
Vol 2131 (2) ◽  
pp. 022119
Author(s):  
N S Mogilevskaya ◽  
V V Dolgov

Abstract The situation when an illegal user intercepts data from the communication channel of two legal users is considered. The data in the legal channel is protected from distortion by error correction codes. It is assumed that the intercept channel may be noisier than the legal channel. And, consequently, the interceptor receives low-quality data. The possibility of using a special type of error-correction code decoders by an illegal user to restore damaged data is discussed. The interceptor model is constructed. The model includes a receiving block of the intercept channel, as well as several auxiliary blocks, such as a memory device, a block for determining the quality of communication in the legal channel, databases with possible decoders and their parameters. Examples are given that show the potential capabilities of the interceptor. The examples demonstrate the difference in decoding quality between different decoders for LDPC codes and Reed-Muller codes. These examples show that an illegal user with the various decoders described in the open press can receive information with satisfactory quality even at a weak signal level in the intercept channel. The constructed model can be useful in the tasks of developing methods of protection against intruders who organize illegitimate data interception channels.


2021 ◽  
Vol 25 (1) ◽  
pp. 79-83
Author(s):  
Evgeniy O. Kiktenko ◽  
Aleksei O. Malyshev ◽  
Aleksey K. Fedorov

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