Encryption and Compression by DCT Coefficient Diffusion Using Generalized Logistic Equation

Abstract

In the present-day era of typical social media communications, it is vital that privacy to newlinebe preserved due to attacks on multimedia data through various methods. It is well newlineknown that the encryption standards either lack in keyspace or poor encryption strength. newlineHence, it is proposed to use a novel method in which both keyspace and encryption are newlineincreased. Discrete cosine transforms (DCT) of the image are encrypted using a newlinegeneralized logistic equation. Due to this idea, both compression and encryption are newlinedone simultaneously. Before applying DCT, the image is shuffled using Arnold Cat newlineMap. The proposed compression and encryption method is validated using several newlinechaotic metrics such as; Bifurcation diagram, Mutual information, Kolmogorov Sinai newlineEntropy density, Kolmogorov Sinai Entropy generality, Space-Amplitude diagram, newlineSpace-Time diagram. Intruders are discouraged through the improved metrics such as newlineNPCR (Number of Pixels changing rate), UACI (Unified Averaged changed intensity), newlineand mutual information among the lattices used as the key. In the same way, image newlinereconstruction quality is improved and verified through the metrics such as PSNR (Peak newlineSignal to noise ratio) and FOM (Figure of Merit). Compression performance is newlineevaluated through the metric CR (Compression ratio). The performance is evaluated newlinefor both gray and color image databases under a noisy channel environment. newline