In this paper, a scheme to realize encryption and digital identity authentication at the same time is proposed for enhancing the physical-layer security of point-to-point optical links (PPOL). Exploiting identity code encrypted by the key as authentication information effectively resists passive eavesdropping attacks in fingerprint authentication. The proposed scheme theoretically realizes secure key generation and distribution (SKGD) by phase noise estimation of the optical channel and the generation of identity codes with good randomness and unpredictability by the four-dimensional (4D) hyper-chaotic system. The local laser, erbium doped fiber amplifier (EDFA), and public channel provide the entropy source of uniqueness and randomness to extract symmetric key sequences for legitimate partners. The simulation conducted in a quadrature phase shift keying (QPSK) PPOL system over 100km standard single mode fiber verify successfully that 0.95Gbit/s error-free SKGD. The unpredictability and high sensitivity to the initial value and control parameters of the 4D hyper-chaotic system provide a huge space of ~10 125 for identity codes, which is sufficient to resist exhaustive attack. With the proposed scheme, the security level of key and identity can be increased markedly.
In this paper, a scheme to realize encryption and digital identity authentication at the same time is proposed for enhancing the physical-layer security of point-to-point optical links (PPOL). Exploiting identity code encrypted by the key as authentication information effectively resists passive eavesdropping attacks in fingerprint authentication. The proposed scheme theoretically realizes secure key generation and distribution (SKGD) by phase noise estimation of the optical channel and the generation of identity codes with good randomness and unpredictability by the four-dimensional (4D) hyper-chaotic system. The local laser, erbium doped fiber amplifier (EDFA), and public channel provide the entropy source of uniqueness and randomness to extract symmetric key sequences for legitimate partners. The simulation conducted in a quadrature phase shift keying (QPSK) PPOL system over 100km standard single mode fiber verify successfully that 0.95Gbit/s error-free SKGD. The unpredictability and high sensitivity to the initial value and control parameters of the 4D hyper-chaotic system provide a huge space of ~10 125 for identity codes, which is sufficient to resist exhaustive attack. With the proposed scheme, the security level of key and identity can be increased markedly.
A point to multi-point physical-layer secure key generation and distribution (SKGD) scheme is proposed and demonstrated in passive optical networks (PONs), where the optical line terminal (OLT) broadcasts optical lights with fast fluctuating states of polarization (SOPs) to the optical network units (ONUs). The highly correlated key waveforms are shared between OLT and ONUs, and the high-level security of the SKGD scheme is guaranteed by the high sensitivity of SOP dynamics associated with the specific fiber links. As a proof of concept, a 3.9 Gb/s SKGD is achieved over 11 km single-mode fiber, where a Sagnac interferometer-based polarization scrambler is constructed as the high-speed random source. Moreover, the generated key sequences are verified to be error free and truly random. The proposed SKGD scheme offers a flexible solution for security enhancement in PONs, and is also compatible with the current PON infrastructure.
Abstract In this paper, a novel secure communication scheme based on temporal spreading and dual-phase perturbation is proposed to improve security at the physical layer. For one thing, the traditional electro-optical feedback phase encryption system is significantly sophisticated by the introduction of additional synchronized chaotic phase encryption. Besides, more keys in this system are available, with the attendance of dispersion and optical chaos, the key space is notably enhanced to ∼2 36 , resisting the eavesdropping attacks. After passing through a series of encryption devices, the information is ultimately displayed as a noise-like signal. A 32 Gb s −1 on-off keying signal is successfully transmitted over a 100 km standard single-mode fiber. Simulation results show that by selecting the appropriate system parameters, a bit error rate as low as 10 −10 can be obtained for legitimate terminals, and the effect of different hardware parameter mismatches on the decryption performance is also investigated which indicates a certain tolerance range for the mismatch of each parameter. This paper provides a new idea to combine an electro-optical feedback system with optical chaos to establish optical secrecy communication.
With the wide application of large-capacity and high-speed optical networks, its security has become a current research focus. Due to the limitations of traditional key distribution and encryption schemes, this paper proposes an innovative key distribution and encryption control scheme based on physical layer channel feature extraction and analysis. First of all, the transceiver terminal extracts the physical characteristics of the fiber channel separately, and generates a consensus key through quantization coding. Second, use the generated key base to encrypt the transmission sequence, map the Quadrature Phase Shift Keying (QPSK) signal to the high-order 1024×1024-QAM signal, and use the noise stream to perform the high-order QAM. The signal is flooded. The system utilizes channel non-replication and randomness of channel noise, the security and randomness of the key are good, and the key formation rate is high and the key generation equipment is simple. The system uses high-order QAM modulation, which increases the security of the system. The experimental results show that the coding rate of the key generated by the system reaches 400kb/s, and the coding performance of the key is better; the operating key is generated by the key base extension, which has strong anti-interception ability; the system has a low bit error rate and secure transmission Good performance.
Point to Point Optical Link (PPOL) and Inter Vehicular Visible Light Communications (IVVLC) as susceptible to many security threats including jamming, eavesdropping, interception and physical infrastructure attack. To address this problem, researchers have recently proposed to generate secret keys from the randomness of the physical environment such as wireless communication channel fading characteristics, phase fluctuation inside optical fiber and polarization mode dispersion in a long-haul network. In this thesis, I presented a novel symmetric physical layer based secret key generation schemes for both PPOL and IVVLC. Polarization Mode Dispersion (PMD) of long optical fiber links and intensity variations due to road surface roughness along with driving behavior are exploited as a random channel characteristic to generate cryptographic keys for PPOL and IVVLC, respectively. It has been demonstrated, modulation of a probe signal caused by PMD in a high speed PPOL (40Gb/s and 60Gb/s) is reciprocal with average Pearson correlation coefficient of 0.862, despite the presence of optical nonlinearities, dispersion, and noise in the system. 128-bit symmetric cryptographic key has been successfully generated using the proposed scheme. Moreover, PMD based encryption keys passed the National Institute of Standards and Technology (NIST) tests. It is proved through simulations of a 50km link that, with optimal key generation settings, symmetric keys can be generated with high randomness (high P-values for NIST randomness tests) and with sufficient generation rates (>50%). Furthermore, this key generation algorithm successfully generated, with extremely low error, high entropy, secret keys with lengths up to 128-bits using a 1kbps probe signal with the proposed scheme. It is also found that the vehicular visible light channels have high entropy (e.g., 12-14 bits for 5000 samples) and that separate channels are highly uncorrelated to one another (e.g., Pearson correlation coefficient of 0.32). These results prove that physical communication channel can be exploited to generate symmetric cryptographic keys.
We present a symmetric physical layer based secret key generation scheme for Point-to-Point Optical Link (PPOL) communication by exploiting Polarization Mode Dispersion (PMD) as a random and inimitable channel characteristic. The randomness and security strength of generated cryptographic keys based on PMD is significantly high. In this paper, we present that random modulation of a probe signal caused by PMD in a high-speed data communication network (40Gb/s and 60Gb/s) is reciprocal with average Pearson correlation coefficient of 0.862, despite the presence of optical nonlinearities, dispersion, and noise in the system. 128-bit symmetric cryptographic key has been successfully generated using the proposed scheme. Moreover, PMD based encryption keys passed the National Institute of Standards and Technology (NIST) tests. We have shown through simulations with a 50km link that, with optimal key generation settings, symmetric keys can be generated with high randomness (high P-values for NIST randomness tests) and with sufficient generation rates (>50%). Furthermore, we considered an attack model of a non-invasive adversary intercepting at 10km into the link and found that the generated keys have high average key bit mismatch rates (>40%).
High-speed physical-layer secure key generation and distribution (SKGD) schemes via channel reciprocity are achieved using external electro-optical modulation or random source distribution via additional fiber links. Here, we propose and demonstrate an SKGD scheme using the fluctuation of polarization states from an amplified spontaneous emission (ASE) source, without any external electro-optical modulation or additional fiber link. Experimentally, an error-free key generation rate (KGR) of 10.1 Gb/s is achieved over a 10-km standard single-mode fiber (SSMF), with true randomness originating from ASE. Moreover, the single fiber channel can be shared for SKGD as well as data transmission, allowing the integration of the proposed SKGD with the deployed fiber infrastructure.