Entropy

A Hybrid Information Reconciliation Method for Physical Layer Key Generation

Guyue Li, Zheying Zhang, Yi Yu, Aiqun Hu

Published Jul 14, 2019• 29 citations

Abstract

Physical layer key generation (PKG) has become a research focus as it solves the key distribution problem, which is difficult in traditional cryptographic mechanisms. Information reconciliation is a critical process in PKG to obtain symmetric keys. Various reconciliation schemes have been proposed, including the error detection protocol-based approach (EDPA) and error correction code-based approach (ECCA). Both EDPA and ECCA have advantages and drawbacks, regarding information leakage, interaction delay, and computation complexity. In this paper, we choose the BBBSS protocol from EDPA and BCH code from ECCA as a case study, analyzing their comprehensive efficiency performance versus pass number and bit disagreement ratio (BDR), respectively. Next, we integrate the strength of the two to design a new hybrid information reconciliation protocol (HIRP). The design of HIRP consists of three main phases, i.e., training, table lookup, and testing. To comprehensively evaluate the reconciliation schemes, we propose a novel efficiency metric to achieve a balance of corrected bits, information leakage, time delay, and computation time, which represents the effectively corrected bits per unit time. The simulation results show that our proposed method outperforms other reconciliation schemes to improve the comprehensive reconciliation efficiency. The average improvement in efficiency is 2.48 and 22.36 times over the BBBSS and BCH code, respectively, when the range of the BDR is from 0.5% to 11.5%. Compared to the BBBSS protocol and the BCH code, HIRP lies at a mid-level in terms of information leakage and computation time cost. Besides, with the lowest time delay cost, HIRP reaches the highest reconciliation efficiency.

DOI: 10.3390/e21070688

Related papers

An Adaptive Information Reconciliation Protocol for Physical-Layer Based Secret Key Generation

Zheying Zhang, Guyue Li, Aiqun Hu

Physical-layer based secret key generation (SKG) becomes a research focus as it solves key distribution problem which is difficult in traditional cryptographic mechanism. To remove the disagreements caused by imperfect reciprocity of communicating parties, information reconciliation is a critical process in SKG to obtain symmetric keys. Various reconciliation schemes are proposed, e.g. BBBSS, Cascade, BCH code and Turbo code. Reconciliation efficiency is a common evaluation index which takes reconciliation success rate and information leakage rate into account. However, time delay caused by information interaction and computation overhead may affect reconciliation performance under specific scenarios. Therefore, a comprehensive evaluation metric is required to compare existing schemes. Besides, channel condition changes all the time in real mobile communication systems, and most existing reconciliation schemes only work well in certain channel conditions. Hence, a reconciliation scheme which can adapt to time-varying channel condition is required. In this paper, we introduce a novel comprehensive reconciliation efficiency index (CREI) to evaluate existing reconciliation schemes and propose an adaptive information reconciliation scheme selection (AIRSS) protocol to maximize CREI. The simulation results show the superiority of AIRSS and present recommendations of reconciliation scheme selection in different scenarios.

IEEE Vehicular Technology ConferenceApr 1, 201910 citations

A Novel Hybrid Protocol and Code Related Information Reconciliation Scheme for Physical Layer Secret Key Generation

Et al. Sujata Kadam

Wireless networks are vulnerable to various attacks due to their open nature, making them susceptible to eavesdropping and other security threats. Eavesdropping attack takes place at the physical layer. Traditional wireless network security relies on cryptographic techniques to secure data transmissions. However, these techniques may not be suitable for all scenarios, especially in resource-constrained environments such as wireless sensor networks and adhoc networks. In these networks having limited power resources, generating cryptographic keys between mobile entities can be challenging. Also, the cryptographic keys are computationally complex and require key management infrastructure. Physical Layer Key Generation (PLKG) is an emerging solution to address these challenges. It establishes secure communication between two users by taking advantage of the wireless channel's inherent features. PLKG process involves channel probing, quantization, information reconciliation (IR) and privacy amplification to generate symmetric secret key. The researchers have used various PLKG techniques to get the secret key, sTop of Form till they face problems in the IR scheme to obtain symmetric keys between the users who share the same channel for communication. Both the code based and protocol based methods proposed in the literature have advantages and limitations related to their performance parameters such as information leakage, interaction delay and computation complexity. This research work proposes a novel IR mechanism that combines the protocol and code-based error correction methods to obtain reduced Bit Mismatch Rate (BMR), reduced information leakage, reduced interaction delay, and reduced computational time to enhance physical layer secret key's quality. In the proposed research work, the channel samples are generated using the Received Signal Strength (RSS) and Channel Impulse Response (CIR) parameters. These samples are quantized using Vector Quantization with Affinity Propagation Clustering (VQAPC) method to generate the preliminary key. The samples collected by the two users who wish to communicate, (for example Alice and Bob) will be different due to noise in the channel and hardware limitations. Hence their preliminary keys will be different. Removing this discrepancy between Bob's and Alice's initial keys, using novel Hybrid Protocol and Code related Information Reconciliation (HPC-IR) scheme to generate error corrected key, is the most important contribution of this research work. This key is further encoded by the MD5 hash function to generate a final secret key for exchanging information between two users over the wireless channel. It is observed that the proposed HPC-IR scheme achieves BMR of 19.4%, information leakage is 0.002, interaction delay is 0.001 seconds and computation time is 0.02 seconds.

International Journal on Recent and Innovation Trends in Computing and CommunicationNov 5, 20230 citations

An Efficient Information Reconciliation Scheme via Partial Encoding for Physical Layer Secret Key Generation

Toshiki Matsumine, Hideki Ochiai, Junji Shikata

This letter proposes an efficient information reconciliation coding scheme for physical layer secret key generation. We consider a high-rate key generation system, where multiple key bits are extracted from one Gaussian random variable source, each of which has different reliability depending on its bit level. Although the conventional bit-interleaved coded modulation (BICM)-type reconciliation protects all the key bits by forward error correction (FEC), the computational complexity associated with its encoding and decoding can be a bottleneck in achieving a high secret key rate especially for low-cost devices with limited computational capabilities. To alleviate this complexity issue, we propose a new reconciliation scheme that efficiently reduces the complexity by applying FEC only to the least reliable bits (LRBs). We demonstrate by simulations that the proposed information reconciliation based on partial encoding achieves a lower key bit mismatch rate (BMR) than the conventional BICM-type reconciliation even with lower decoding complexity. Furthermore, we provide a lower bound on the asymptotic BMR of the proposed scheme that is useful for estimating the performance in high signal-to-noise ratio (SNR) regimes.

IEEE Communications LettersApr 1, 20246 citations

One-way information reconciliation schemes of quantum key distribution

Li Yang, Hua Dong, Li Zhao

With the rapid improvement of quantum computing technology, quantum key distribution(QKD) is a hot technology. Information reconciliation is a key step of QKD which is useful for correcting key error. Classical message interaction is necessary in a practical information reconciliation scheme, which makes the efficiency of these protocols decreased. Therefore, some one-way information reconciliation schemes based on low-density parity-check(LDPC) codes and polar codes are proposed. Here we propose a concatenated method of IR schemes which can achieve any given error rate level without the need of interactions. Compared with the one-way IR schems based on LDPC codes and polar codes, the IR schemes based on the proposed concatenated method can get lower bit error rates after error correction, which can also reduce the communication delay and system complexity of QKD, improve the final key generation rate and enhance the practicability of QKD system.

CybersecurityMay 22, 201910 citations

Secret Key Generation Using Polar Code-Based Reconciliation Method in 5G

Jingnuo Peng, Kaizhi Huang, Shuaifang Xiao +1 more

Physical layer key generation is one of the promising candidate technology schemes for communication network encryption as it promises to solve the difficulties in traditional cryptographic mechanisms. However, due to the existence of unequal key bits in the process of key generation, the practical application of physical layer key generation is greatly hindered. In this paper, in order to eliminate the key inconsistency problem, we propose a Polar code-based information reconciliation scheme (PIRS) by combining the design mechanism of the 5th generation (5G) physical control channel processing flow in the 5G physical layer protocol. The Monte Carlo simulation results show that our proposed method can significantly reduce the key disagreement rate (KDR) and increase the key generation rate (KGR) for both parties in communication, even when the signal-to-noise ratio is low.

International Conference on Advanced Computing and Endogenous SecurityApr 21, 20225 citations

Performance of an Improved One-Way Error Reconciliation Protocol Based on Key Redistribution

Zhao Fen

In data post-processing for quantum key distribution, it is essential to have a highly efficient error reconciliation protocol. Based on the key redistribution scheme, we analyze a one-way error reconciliation protocol by data simulation. The relationship between the error correction capability and the key generation efficiency of three kinds of Hamming code are demonstrated. The simulation results indicate that when the initial error rates are(0,1.5%],(1.5,4%], and(4,11%], using the Hamming(31,26),(15,11), and(7,4) codes to correct the error, respectively, the key generation rate will be maximized. Based on this, we propose a modified one-way error reconciliation protocol which employs a mixed Hamming code concatenation scheme. The error correction capability and key generation rate are verified through data simulation. Using the parameters of the posterior distribution based on the tested data, a simple method for estimating the bit error rate(BER) with a given confidence interval is estimated. The simulation results show that when the initial bit error rate is 10.00%, after 7 rounds of error correction, the error bits are eliminated completely, and the key generation rate is 10.36%; the BER expectation is 2.96×10-10, and when the confidence is 95% the corresponding BER upper limit is 2.17×10-9. By comparison, for the single(7,4) Hamming code error reconciliation scheme at a confidence of 95%,the key generation rate is only 6.09%, while the BER expectation is 5.92×10-9, with a BER upper limit of 4.34×10-8. Hence, our improved protocol is much better than the original one.

China CommunicationsJan 1, 20140 citations