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Substitution-boxes, or simply S-boxes, are used to increase confidentiality in the substitution stage of most cryptosystem approaches. In this paper, an efficient method for the construction of an S-box based on a sine map is proposed. The proposed S-box is able to generate random integer sequences with highly efficient nonlinearity in the generated values. The cryptographic analyses show that the proposed S-box method is of high performance and can be used with great potential for prominent prevalence in designing symmetric cryptosystems and copy right protection. [ABSTRACT FROM AUTHOR]

In this paper, a new chaos-based partial image encryption scheme based on Substitution-boxes (S-box) constructed by chaotic system and Linear Fractional Transform (LFT) is proposed. It encrypts only the requisite parts of the sensitive information in Lifting-Wavelet Transform (LWT) frequency domain based on hybrid of chaotic maps and a new S-box. In the proposed encryption scheme, the characteristics of confusion and diffusion are accomplished in three phases: block permutation, substitution, and diffusion. Then, we used dynamic keys instead of fixed keys used in other approaches, to control the encryption process and make any attack impossible. The new S-box was constructed by mixing of chaotic map and LFT to insure the high confidentiality in the inner encryption of the proposed approach. In addition, the hybrid compound of S-box and chaotic systems strengthened the whole encryption performance and enlarged the key space required to resist the brute force attacks. Extensive experiments were conducted to evaluate the security and efficiency of the proposed approach. In comparison with previous schemes, the proposed cryptosystem scheme showed high performances and great potential for prominent prevalence in cryptographic applications. [ABSTRACT FROM AUTHOR]