Efficient transmission of chaotic and AES encrypted images with OFDM over an AWGN channel

This paper presents a comparison study between the fast Fourier transform based orthogonal frequency division multiplexing (FFT-OFDM), the discrete cosine transform based orthogonal frequency multiplexing (DCT-OFDM) and the discrete wavelet transform based orthogonal frequency multiplexing (DWT-OFDM) for the transmission of chaotic and AES (Advanced encryption standard) encrypted images. Concentration in the paper is on the transmission of encrypted images for the purpose of high definition television (HDTV) broadcasting. This comparison study is held to determine the best one suitable for HDTV broadcasting of encrypted images. The encryption approach adopted in this paper is based on chaotic Baker maps because the encoding and decoding steps in this approach are simple and fast enough for HDTV applications. This approach belongs to the family of fast permutation algorithms. And AES is also discussed where it´s algorithm has very good performance in both hardware and software implementations. It also has very low memory requirements, and the algorithm´s internal round structure benefits from instruction level parallelism. This ability will improve its performance. The different types of channels and the different parameters of OFDM modulation are considered in the comparison. The experimental results reveal the superiority of the FFT-OFDM over the DCT-OFDM for the transmission of encrypted images.