Encryption Quality Measurement of a Proposed Cryptosystem Algorithm for the Colored Images Compared with Another Algorithm

In this paper, a proposed cryptosystem algorithm based on two different chaotic systems is presented. The proposed cryptosystem algorithm is designated as PCACH. A recently developed encryption algorithm which is designated here, as HuXia is reviewed. These two algorithms are applied to three images of different color frequencies, i.e., different types of colored-images are encrypted with each of the two encryption algorithms. Both of them are applied to the different images with two different types of encryption modes, Electronic Code Book (ECB) and Cipher Block Chaining (CBC). Visual inspection is not sufficient to assess the quality of encryption so other measuring factors are considered based on measuring the maximum deviation and the Correlation Coefficient (CC) between the original and the encrypted images. For judging the force of security, we measure the plain-text sensitivity by using Number of Pixels Change Rate (NPCR) and Unified Average Changing Intensity (UACI) analysis, measuring information entropy and measuring the key sensitivity. Also, the encryption/decryption time and the throughput are measured for the two algorithms. The results suggest that PCACH is a very good algorithm and superior to HuXia.