文摘
To enhance the security of H.264/AVC streaming, such as that for Internet protocol television, over a passive optical network (PON), a dynamic reconfigurable coding–decoding scheme, based on a chaotic sequence, was demonstrated and characterised by pseudo randomness and a maximal period. Compared with conventional optical code-division multiple-access (OCDMA) PONs, without providing a dynamic reconfigurable mechanism and trigger timing, a secure mechanism was generated using a proposed chaos/maximal length sequence (M-sequence) mapping algorithm and embedded in a codebook to control an electrical controller (register). Because the state of the electrical controller (register) is used by the chaos/M-sequence mapping time sequence pattern to trigger a switch matrix and then vary the M-sequence signature address code for each authorised user, the scrambling and interleaving function of the encryption scheme was implemented in the OCDMA-PON physical layer for various M-sequence signature address codes to carry individual H.264/AVC transmissions of the same channel. The proposed chaos/M-sequence mapping algorithm provided similar pseudo randomness and higher variance effectiveness compared with a general uniform distribution of the pseudo-random, autocorrelation, and cross-correlation properties of the proposed time sequence. In addition, the scrambling and interleaving efficiency was determined to be sufficiently high by the reduced peak signal-to-noise ratio of encrypted videos and the produced unidentifiable videos for unauthorised users.KeywordsDynamic reconfigurable encryption–decryptionOptical code-division multiple-access (OCDMA)Passive optical network (PON)Chaos/M-sequence mapping algorithm (CMmA)H.264/AVC streamingScrambling encryption
