© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Optics Express

Improving the privacy of optical steganography with temporal phase masks

Z. Wang, Mable P. Fok, Lei Xu, John H.C. Chang, Paul R. Prucnal

Published Mar 11, 2010• 27 citations

Abstract

Temporal phase modulation of spread stealth signals is proposed and demonstrated to improve optical steganography transmission privacy. After phase modulation, the temporally spread stealth signal has a more complex spectral-phase-temporal relationship, such that the original temporal profile cannot be restored when only dispersion compensation is applied to the temporally spread stealth signals. Therefore, it increases the difficulty for the eavesdropper to detect and intercept the stealth channel that is hidden under a public transmission, even with a correct dispersion compensation device. The experimental results demonstrate the feasibility of this approach and display insignificant degradation in transmission performance, compared to the conventional stealth transmission without temporal phase modulation. The proposed system can also work without a clock transmission for signal synchronization. Our analysis and simulation results show that it is difficult for the adversary to detect the existence of the stealth transmission, or find the correct phase mask to recover the stealth signals.

DOI: 10.1364/oe.18.006079

Related papers

Temporal phase mask encrypted optical steganography carried by amplified spontaneous emission noise

Ben Wu, Zhenxing Wang, Bhavin J. Shastri +3 more

A temporal phase mask encryption method is proposed and experimentally demonstrated to improve the security of the stealth channel in an optical steganography system. The stealth channel is protected in two levels. In the first level, the data is carried by amplified spontaneous emission (ASE) noise, which cannot be detected in either the time domain or spectral domain. In the second level, even if the eavesdropper suspects the existence of the stealth channel, each data bit is covered by a fast changing phase mask. The phase mask code is always combined with the wide band noise from ASE. Without knowing the right phase mask code to recover the stealth data, the eavesdropper can only receive the noise like signal with randomized phase.

Optics Express•Jan 9, 2014•37 citations

Demonstration of optical steganography transmission using temporal phase coded optical signals with spectral notch filtering

Xuezhi Hong, Dawei Wang, Lei Xu +1 more

A novel approach is proposed and experimentally demonstrated for optical steganography transmission in WDM networks using temporal phase coded optical signals with spectral notch filtering. A temporal phase coded stealth channel is temporally and spectrally overlaid onto a public WDM channel. Direct detection of the public channel is achieved in the presence of the stealth channel. The interference from the public channel is suppressed by spectral notching before the detection of the optical stealth signal. The approach is shown to have good compatibility and robustness to the existing WDM network for optical steganography transmission.

Optics Express•May 26, 2010•50 citations

Phase-mask covered optical steganography based on amplified spontaneous emission noise

Ben Wu, Zhenxing Wang, Bhavin J. Shastri +2 more

Phase mask encryption is proposed to improve the transmission privacy of an optical steganography system. The stealth signal carried by amplified spontaneous emission noise is encrypted by a fast changing code.

IEEE Photonics Conference•Sep 1, 2013•4 citations

Dispersion Deployment and Compensation for Optical Steganography Based on Noise

Ben Wu, Matthew P. Chang, Bhavin J. Shastri +2 more

The system tolerance to the dispersion of optical steganography and the deployment of dispersion to enhance secure transmission has been experimentally demonstrated and theoretically studied. Since the stealth signal is carried by amplified spontaneous emission noise, which has a much wider bandwidth compared with the laser carrier, the stealth channel is more sensitive to dispersion and has less tolerance to the uncompensated dispersion. On the other hand, the dispersion effect in the stealth channel can be employed to hide the stealth signal in the time domain. The extra dispersion at the transmitter and the receiver functions as a key pair for the optical encryption and the optical steganography.

IEEE Photonics Technology Letters•Nov 3, 2015•21 citations

Optical Signal Processing and Stealth Transmission for Privacy

Ben Wu, Bhavin J. Shastri, Prateek Mittal +2 more

Optical encryption, key generation, and optical stealth transmission techniques for protecting the privacy of communication in optical networks are proposed and summarized. The signal processing methods based on fiber components provide ways to encrypt data and generate encryption keys at the speed of data transmission in optical fibers. Private and confidential communication is achieved without compromising the capacity and bandwidth of the optical network. Optical stealth transmission can hide the signal in plain sight. Because an eavesdropper can neither read the data nor detect the existence of the transmitted signal, optical stealth transmission provides a higher level of privacy. A hybrid system which includes both the public channels and stealth channels can effectively provide anonymous communication and defend against traffic analysis.

IEEE Journal of Selected Topics in Signal Processing•Apr 20, 2015•32 citations

Optical steganography based on amplified spontaneous emission noise

Ben Wu, Zhenxing Wang, Yue Tian +4 more

We propose and experimentally demonstrate an optical steganography method in which a data signal is transmitted using amplified spontaneous emission (ASE) noise as a carrier. The ASE serving as a carrier for the private signal has an identical frequency spectrum to the existing noise generated by the Erbium doped fiber amplifiers (EDFAs) in the transmission system. The system also carries a conventional data channel that is not private. The so-called "stealth" or private channel is well-hidden within the noise of the system. Phase modulation is used for both the stealth channel and the public channel. Using homodyne detection, the short coherence length of the ASE ensures that the stealth signal can only be recovered if the receiver closely matches the delay-length difference, which is deliberately changed in a dynamic fashion that is only known to the transmitter and its intended receiver.

Optics Express•Jan 18, 2013•101 citations

Temporal phase modulation of spread stealth signals is proposed and demonstrated to improve optical steganography transmission privacy. After phase modulation, the temporally spread stealth signal has a more complex spectral-phase-temporal relationship, such that the original temporal profile cannot be restored when only dispersion compensation is applied to the temporally spread stealth signals. Therefore, it increases the difficulty for the eavesdropper to detect and intercept the stealth channel that is hidden under a public transmission, even with a correct dispersion compensation device. The experimental results demonstrate the feasibility of this approach and display insignificant degradation in transmission performance, compared to the conventional stealth transmission without temporal phase modulation. The proposed system can also work without a clock transmission for signal synchronization. Our analysis and simulation results show that it is difficult for the adversary to detect the existence of the stealth transmission, or find the correct phase mask to recover the stealth signals.

A temporal phase mask encryption method is proposed and experimentally demonstrated to improve the security of the stealth channel in an optical steganography system. The stealth channel is protected in two levels. In the first level, the data is carried by amplified spontaneous emission (ASE) noise, which cannot be detected in either the time domain or spectral domain. In the second level, even if the eavesdropper suspects the existence of the stealth channel, each data bit is covered by a fast changing phase mask. The phase mask code is always combined with the wide band noise from ASE. Without knowing the right phase mask code to recover the stealth data, the eavesdropper can only receive the noise like signal with randomized phase.

A novel approach is proposed and experimentally demonstrated for optical steganography transmission in WDM networks using temporal phase coded optical signals with spectral notch filtering. A temporal phase coded stealth channel is temporally and spectrally overlaid onto a public WDM channel. Direct detection of the public channel is achieved in the presence of the stealth channel. The interference from the public channel is suppressed by spectral notching before the detection of the optical stealth signal. The approach is shown to have good compatibility and robustness to the existing WDM network for optical steganography transmission.

The system tolerance to the dispersion of optical steganography and the deployment of dispersion to enhance secure transmission has been experimentally demonstrated and theoretically studied. Since the stealth signal is carried by amplified spontaneous emission noise, which has a much wider bandwidth compared with the laser carrier, the stealth channel is more sensitive to dispersion and has less tolerance to the uncompensated dispersion. On the other hand, the dispersion effect in the stealth channel can be employed to hide the stealth signal in the time domain. The extra dispersion at the transmitter and the receiver functions as a key pair for the optical encryption and the optical steganography.

Optical encryption, key generation, and optical stealth transmission techniques for protecting the privacy of communication in optical networks are proposed and summarized. The signal processing methods based on fiber components provide ways to encrypt data and generate encryption keys at the speed of data transmission in optical fibers. Private and confidential communication is achieved without compromising the capacity and bandwidth of the optical network. Optical stealth transmission can hide the signal in plain sight. Because an eavesdropper can neither read the data nor detect the existence of the transmitted signal, optical stealth transmission provides a higher level of privacy. A hybrid system which includes both the public channels and stealth channels can effectively provide anonymous communication and defend against traffic analysis.

We propose and experimentally demonstrate an optical steganography method in which a data signal is transmitted using amplified spontaneous emission (ASE) noise as a carrier. The ASE serving as a carrier for the private signal has an identical frequency spectrum to the existing noise generated by the Erbium doped fiber amplifiers (EDFAs) in the transmission system. The system also carries a conventional data channel that is not private. The so-called "stealth" or private channel is well-hidden within the noise of the system. Phase modulation is used for both the stealth channel and the public channel. Using homodyne detection, the short coherence length of the ASE ensures that the stealth signal can only be recovered if the receiver closely matches the delay-length difference, which is deliberately changed in a dynamic fashion that is only known to the transmitter and its intended receiver.