Iranian Society of Cryptology The ISC International Journal of Information Security 2008-2045 7 1 2015 01 01 Optimizing image steganography by combining the GA and ICA 47 58 39204 10.22042/isecure.2015.7.1.5 EN F. Sadeghi F. Zarisfi Kermani M. Kuchaki Rafsanjani Journal Article 2014 12 27 In this study, a novel approach which uses combination of steganography and cryptography for hiding information into digital images as host media is proposed. In the process, secret data is first encrypted using the mono-alphabetic substitution cipher method and then the encrypted secret data is embedded inside an image using an algorithm which combines the random patterns based on Space Filling Curves (SFC) and the optimal pair-wise LSB matching method. We employ a modified Imperialist Competitive Algorithm by Genetic Algorithm operations, namely Discrete Imperialist Competitive Algorithm (DICA), to perform the optimal pair-wise LSB matching method and find the suboptimum adjustment list. The performance of the proposed method is compared with other methods with respect to Peak Signal to Noise Ratio (PSNR). The PSNR value of the proposed method is higher than the state-of-the-art methods by almost 4dB to 5dB. https://www.isecure-journal.com/article_39204_ad5ba4274138d6f039cc4cc1c14867cf.pdf