Dynamic updated key distribution encryption scheme with the wireless rate of 102†Gb/s based on a syncretic W band-PON transmission system.

In this paper, a dynamic updated key distribution encryption scheme based on syncretic W band-passive optical network (PON) is proposed. The 102 Gb/s encrypted data rate using 64QAM is successfully transmitted over the 50 m wireless distance under 15% soft-decision forward error correction (SD-FEC) for a pre-FEC bit error rate (BER) threshold of 1.56 × 10-2. The scheme can realize an error-free public key transmission and public key updates up to 1014 times. In the encryption transmission system, there is a small deviation of the private key, and the received BER is more than 0.45. As far as we know, this is the first time to complete a dynamic key distribution based on a syncretic W band-PON system.

Sliced chaotic encrypted transmission scheme based on key masked distribution in a W-band millimeter-wave system.

In order to guarantee the information of the W-band wireless communication system from the physical layer, this paper proposes the sliced chaotic encrypted (SCE) transmission scheme based on key masked distribution (KMD). The scheme improves the security of free space communication in the W-band millimeter-wave wireless data transmission system. In this scheme, the key information is embedded into the random position of the ciphertext information, and then the ciphertext carrying the key information is encrypted by multi-dimensional chaos. Chaotic system 1 constructs a three-dimensional discrete chaotic map for implementing KMD. Chaotic system 2 constructs complex nonlinear dynamic behavior through the coupling of two neurons, and the masking factor generated is used to realize SCE. In this paper, the transmission of 16QAM signals in a 4.5 m W-band millimeter-wave wireless communication system with a rate of 40 Gb/s is proved by experiments, and the performance of the system is analyzed. When the input optical power is 5 dBm, the bit error rate (BER) of the legitimate encrypted receiver is 1.23 × 10-3. When the offset of chaotic sequence x and chaotic sequence y is 100, their BERs are more than 0.21. The key space of the chaotic system reaches 10192, which can effectively prevent illegal attacks and improve the security performance of the system. The experimental results show that the scheme can effectively distribute the keys and improve the security of the system. It has great application potential in the future of W-band millimeter-wave wireless secure communication.

High security optical OFDM transmission scheme with four-dimensional region joint encryption based on power division multiplexing.

In this paper, a high security chaotic encryption scheme for orthogonal frequency division multiplexing (OFDM) transmission system is proposed by using power division multiplexing (PDM) technology and four-dimensional region joint encryption. The scheme uses PDM to realize simultaneous transmission of multiple user information, which can achieve a good compromise among system capacity, spectral efficiency and user fairness. In addition, bit cycle encryption, constellation rotation disturbance (CRD) and region joint constellation disturbance (RJCD) are used to realize four-dimensional region joint encryption, effectively improving the physical layer security. The masking factor is generated by the mapping of two-level chaotic systems, which can enhance the nonlinear dynamics and improve the sensitivity of encrypted system. A 11.76 Gb/s OFDM signal transmission over 25 km standard single-mode fiber (SSMF) is experimentally demonstrated. At the forward-error correction (FEC) bit error rate (BER) limit -3.8×10-3, the proposed receiver optical power based on quadrature phase shift keying (QPSK) without encryption, QPSK with encryption, variant-8quadrature amplitude modulation (V-8QAM) without encryption and V-8QAM with encryption are about -13.5dBm, -13.6dBm, -12.2dBm, and -12.1dBm. The key space is up to 10128. The results show that this scheme not only improves the security of the system and the ability to resist attackers, but also improves the system capacity and has the potential to serve more users. It has a good application prospect in the future optical network.

Block compressive sensing chaotic embedded encryption for MCF-OFDM transmission system.

In this paper, we propose a block compressive sensing (BCS) based chaotic embedded encryption scheme for multi-core fiber orthogonal frequency division multiplexing (MCF-OFDM) system. BCS technology is used to recover the entire desired information from the small amounts of data. Meanwhile, a four-dimensional discrete chaotic encryption model generates four masking factors, which are respectively used for coefficient random permutation (CRP), measurement matrix, diffusion and singular value decomposition (SVD) embedding to achieve ultra-high security encryption of four different dimensions. In terms of compressive sensing, CRP can make the discrete cosine transform (DCT) coefficient distribute randomly to improve the sampling efficiency of BCS. Compared with the data without compressive sensing, the data volume is reduced by 75%. In chaotic encryption, SVD technology embeds secret images of noise-like after initial encryption into carrier images to generate encrypted images with visual security. The key space reaches 10120 and it realizes the dual protection of source image data and external representation. The proposed scheme using a 2km 7-core optical fiber achieves a 78.75 Gb/s transmission of encrypted OFDM signals. The received optical power is greater than -14 dBm, and the bit error rate (BER) of core1-core7 is lower than 10-3. When the compression ratio sets to 0.25 and the attack range of encrypted data is up to 30%, the image can still recover the outline and general information. The experimental results show that this scheme can improve the security performance and reduce the complexity of information transmission system. Furthermore, the scheme combines The BCS chaotic embedded encryption technology with MCF-OFDM system, which has a good application prospect in the future optical networks.

Modulation format recognition with transfer learning assisted convolutional neural network using multiple Stokes sectional plane image in multi-core fibers.

A modulation format recognition (MFR) scheme based on multi-core fiber (MCF) is proposed for the next generation of elastic optical networks (EONs). In this scheme, multiple Stokes sectional planes images are used as signal features which are typed into a transfer learning (TL) assisted convolutional neural network (CNN) to realize MFR. Compared with the traditional Jones matrix, the Stokes space mapping method is insensitive to polarization mixing, carrier frequency skew and phase offset, therefore, it has better feature representation ability. TL is introduced to transfer the model used in standard single-mode fiber (SSMF) to MCF transmission, reducing the required training data and complexity. In addition, multiple Stokes sectional planes images are input simultaneously, which improves the accuracy of the neural network. Experimental verifications were performed for a polarization division multiplexing (PDM)-EONs system at a symbol rate of 12.5GBaud by 5 km MCF. Nine modulation formats, including three standard modulation formats (BPSK, QPSK, 8PSK), three uniformly shaped (US) modulation formats (US-8QAM, US-16QAM, US-32QAM) and three probabilistically shaped (PS) modulation formats (PS-8QAM, PS-16QAM, PS-32QAM), were recognized by our scheme. The experimental results show that the scheme achieves high recognition accuracy even at low optical signal-to-noise ratio (OSNR). Moreover, the required number of training samples is less 40% compared to the traditional CNN. The proposed scheme has a high tolerance to the crosstalk damage of MCF itself and can realize the short training time of large-capacity space division multiplexing (SDM)-EONs. Our findings have the potential to be used in the next generation of a SDM fiber transmission system.

Self-propagated chaotic dynamically enhanced optical physical layer encryption communication system based on bidirectional long short-term memory neural network.

The physical layer chaotic encryption of optical communication is considered as an effective secure communication technology, which can protect data and be compatible with existing networks. Theoretically, any chaotic system or chaotic map has ideal complex dynamics. However, due to the limited precision of simulation software and digital equipment, the chaotic system often degrades dynamics, which hinders the further application of digital chaotic system in many fields. In this paper, we propose a self-propagated nonlinear chaotic dynamical enhanced optical physical layer encryption scheme based on bidirectional long short-term memory neural network (Bi-LSTM-NN). The Bi-LSTM-NN is used to train and learn the dynamical enhanced chaotic sequences with different initial values iteratively, and finally the chaotic sequences with self-propagated dynamical enhancement are output. The correlation coefficient (CC) of chaotic sequences by the enhanced chaotic system and Bi-LSTM-NN are more than 0.98. Compared with the original chaotic system, the range of sample entropy above 0.8 is more than 2 times, and the sensitivity of the initial value x0 is up to 2.28 times, and y0 is up to 1.3 times, making the key space reaches 10520. The scheme successfully encrypts constellation points and information in the frequency domain. In addition, the scheme achieves encrypted 16 quadrature amplitude modulation-orthogonal frequency division multiplexing (16QAM-OFDM) signal transmission of 65.9 Gb/s using 2 km 7-core optical fiber. The experimental results show that the scheme can ensure data security, and in the future optical network has a good application prospect.

High-security UFMC optical transmission system of seven-core fiber based on updating the 3D discrete chaotic model.

In this paper, we propose a high-security universal filtered multicarrier (UFMC) transmission system based on a novel, to the best of our knowledge, three-dimensional (3D) discrete chaotic model. The cascade of counters and the 3D discrete chaotic system is used to generate three masking factors and update these factors to encrypt the bitstream, constellation, and the information of the subcarriers. Using this structure, the key space is 10270 and the key is updated in a timely manner. In this work, the encryption scheme solves the dynamic degradation of chaotic cryptography. Experimental results show that there is no significant difference in error performance in comparison with before encryption. Compared with the orthogonal frequency division multiplexing (OFDM) system, the spectrum efficiency of the UFMC system is higher, which reduces out-of-band leakage and interference between services. Considering the complexity constraints of the receiver, the inter-symbol interference caused by fiber dispersion is alleviated by optimizing the distribution of data subbands, and the bit error rate (BER) performance is improved. It is shown that the UFMC system obtains 1.9 dB gain compared with the OFDM system in terms of receiver sensitivity when the BER is 10-3. This encryption scheme has a promising application prospect in short-distance optical access systems in the future.

Multiple Stokes sectional plane image based modulation format recognition with a generative adversarial network.

A novel modulation format recognition (MFR) scheme based on multiple Stokes sectional planes images by generative adversarial network (GAN) is proposed and demonstrated to adapt to next-generation elastic optical network (EON). The application of the encoder, along with the suitable loss function, is able to achieve better performance with regards to MFR of GAN. Experimental verifications were performed for the polarization division multiplexing (PDM)-EON system at a symbol rate of 12.5GBaud. Five modulation formats, including PDM-BPSK, PDM-QPSK, PDM-8PSK, PDM-8QAM, PDM-16QAM, were recognized by our scheme under the condition of practical optical signal-to-noise ratio (OSNR) over both back-to-back transmission and 25km standard signal-mode fiber (SSMF). Specifically, the minimum required OSNR of PDM-16QAM signal to achieve 100% MFR success rate is 18 dB, which is lower than its corresponding 7% forward error correction (FEC) threshold. Results show that, compared with three other machine learning algorithms, the proposed scheme obtains the higher recognition accuracy in the case of the same OSNR. Moreover, the training data required by the proposed scheme is less than the traditional convolutional neural network (CNN) in MFR task, which means the training cost of the neural network is greatly reduced by using GAN.