Traditional chaos-based encryption techniques use pseudorandom codes to implement encryption (e.g., XOR; exclusive or operation) directly, resulting in the violation of requirements for media compression formats for image transmission. In this study, a programmable spatial light modulator (SLM)-based optical wavelength filter was investigated for implementing a scrambling-based cryptographic scheme in WDM networks. A new chaotic tent/hologram mapping algorithm (THmA) and advanced THmA are proposed for triggering the programmable SLM-based filter array. Similarly, an approximately symmetric scheme was used to configure a scrambling SLM-based decryption scheme for performing decryption operations when the initial value and control parameters of the chaotic sequence as individual secret keys are communicated in advance over a private channel. The proposed scheme was evaluated using video application-layer experiments. The results revealed that compared with conventional reconfigurable schemes involving triggered registers and switches behind an AWG router, the number of code space sizes involved in the proposed cryptographic scheme increased by more than 1.31E + 89 times, thereby avoiding eavesdropping attacks in the physical layer. Furthermore, on the basis of the reduced peak signal-to-noise ratio of the encrypted videos and the unidentifiability of the videos to unauthorized users, the scrambling efficiency of the proposed scheme was sufficiently high.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.