To solve the problem of poor reciprocity and redundancy of channel characteristic measurements in secret key generation systems based on wireless channel characteristics, a preprocessing algorithm based on principal component analysis and a new type of hardware fingerprint difference compensation algorithm are proposed. By comparing the changes in the consistency and randomness of the channel state information of the legal communication parties in various test scenarios, it is proved that the algorithm proposed in this paper can effectively improve the channel reciprocity and randomness of key generation.
To solve the problem of poor reciprocity and redundancy of channel characteristic measurements in secret key generation systems based on wireless channel characteristics, a preprocessing algorithm based on principal component analysis and a new type of hardware fingerprint difference compensation algorithm are proposed. By comparing the changes in the consistency and randomness of the channel state information of the legal communication parties in various test scenarios, it is proved that the algorithm proposed in this paper can effectively improve the channel reciprocity and randomness of key generation.
Wireless channel has many characteristics such as reciprocity, time variation, spatial uniqueness, etc. This paper extracted secret key from its noisy radio channel measurements at two nodes by exploiting the reciprocity of wireless channel in time division system. Therefore, the secret key could be generated with the channel estimation to overcome the drawback of the key pre-distribution mechanism. Aiming at solving the problem that the multibit adaptive quantization scheme to achieve low key generation consistency probability, the paper proposes m-windows filtering mechanism to preprocess channel eigenvalues. The simulation results show that the improved algorithm achieves higher key agreement rate and key generation rate, especially when the signal to noise ratio is low, reduce the key inconsistency rate particularly noticeable.
Dynamic secret key generation from wireless channel characteristics is a promising technique for physical layer security. One of the important issues in this field is extending the secret key’s length while preserving its uniformity and randomness. This paper proposes a key generation method based on time-varying and the reciprocity of wireless channels for Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) wireless communication systems. In the proposed technique, the complex impulse response (CIR) of the estimated channel state information (CSI) is extracted, and a quantization algorithm is designed to convert the maximum peaks of the CIR into secret key bits. The effectiveness of the proposed key generation technique is assessed in terms of the randomness of the produced key bits with different key lengths by using a statistical test suite of the National Institute of Standards and Technology (NIST). The proposed technique is employed in the MIMO-OFDM systems with different modulation schemes through Additive White Gaussian Noise (AWGN) and Rayleigh channels. The simulation results show that the secret keys with various key lengths generated from the proposed technique for the MIMO-OFDM systems guarantee randomness. Moreover, the proposed CSI-based key generation technique provides better effectiveness in terms of security when compared to some existing techniques.
Abstract The development of the physical layer key extraction technology provides a new type of encryption mechanism that uses the reciprocity and time varying of wireless channels to generate keys. This encryption mechanism can achieve informational security. However, the wireless channels in the real environment are not completely reciprocal, which results in low consistency in generating the keys. In this paper, we study the influence of RF fingerprint on channel reciprocity, and propose a calibration matrix algorithm resist the RF fingerprint effect. Based on the RF fingerprinting model established previously, we propose two calibration methods from the perspective of RF gain and I/Q gain. The superiority of the two calibration methods is proved by the average system capacity and the linear quantification error rate. Next, we extend the calibration matrix algorithm of narrowband systems to wideband OFDM systems. The applicability of the calibration matrix algorithm in OFDM systems is proved by the linear quantification error rate of the uplink and downlink channels. In order to prove the reliability of the algorithm in the real environment, we use a USRP to collect multiple sets of measured data, and analyse the data through the calibration algorithm. The final result shows that this algorithm makes the uplink and downlink channel reciprocity compensated.
Random and high-agreement secret key generation from noisy wideband channels is challenging due to the autocorrelation inside the channel samples and compromised cross correlation between channel measurements of two keying parties. This paper studies the signal preprocessing algorithms to establish high-agreement uncorrelated secret key in the presence of channel independent eavesdroppers. We first propose a general mathematical model for various preprocessing schemes, including principal component analysis (PCA), discrete cosine transform (DCT) and wavelet transform (WT). Among preprocessing schemes, PCA is proved to achieve the optimal secret key rate. Next, PCA with common eigenvector has been found to outperform PCA with private eigenvector in terms of an overall consideration of key agreement, information leakage, and computational expense. Then, we propose a system level design of key generation, including quantization, information reconciliation, and privacy amplification. Numerical results verify that the key generation enhanced by PCA with common eigenvector can achieve secret key with high key generation rate, low key error rate, and good randomness.
The new power system is the national development strategy and development direction of smart grid. Communication is the basis of the development of the new power system. in the distribution automation business, communication is the weakest link. In order to make electric power communication develop more smoothly, we should improve our awareness of security issues. Because of the particularity of electric power communication, it often has very high requirements for the security of communication. In order to effectively ensure the security of electric power communication data, data encryption technology can be applied to the data transmission process, and the security of information transmission can be improved through the application of encryption and decryption keys.Physical layer key generation technology is a security technology that uses wireless channel characteristics as a random source to generate keys. This technology uses the anisotropy, time variation and spatial uniqueness of wireless channels to generate random sequences, which is different from traditional encryption methods. Physical layer key generation technology does not require the key management and distribution of a third party trusted organization. In theory, it can achieve one encryption at a time to achieve the absolute security of Shannon confidential communication[1]. This paper first briefly introduces the wireless channel physical layer key generation model and the general process of key generation scheme based on channel feature quantization, and then studies the improved optimization scheme based on traditional channel detection, preprocessing and quantization algorithm, so as to effectively improve the key generation performance.
At present, wireless communication technology greatly improves the transmission data rate, but at the same time, it also has higher and higher requirements for the realization of secure communication. From the perspective of information theory, the physical layer key system provides a new way to solve the problem of secure communication in wireless communication system. The uplink and downlink wireless channels with natural reciprocity are used as random sources to generate shared key. Firstly, this paper introduces the steps of a key distribution protocol with multi-level quantization based on the characteristics of wireless channel CSI. Secondly, the security of this kind of key distribution protocol is analyzed by the key generation rate and other evaluation metrics. Furthermore, it is verified by simulation in the typical channel model scenario of 4G communication mode. The simulation results show that the key distribution protocol based on the characteristics of wireless channel can achieve a key generation rate of 5 bits/resource block under the condition of high signal-to-noise ratio (such as 20dB) in the current communication network circumstance, and the generated key sequence has sufficient randomness, so as to achieve effective secure communication.