A New Distinguisher for CubeHash-8/b and CubeHash-15/b Compression Functions

CubeHash is one of the round 2 candidates of the public SHA-3 competition hosted by NIST. It was designed by Bernstein. In this paper we find a new distinguisher to distinguish CubeHash compression function from a random function. This distinguisher principle is based on rotational analysis that formally introduced by Khovratovich and Nikolic. In order to use this technique, we need to compute the probability that four swap functions in CubeHash round function preserve the rotational property for any input pair. We compute these probabilities and find a new distinguisher that distinguish CubeHash-8/b and CubeHash-15/b compression function from a random function with probability greater than and , respectively. Until we know this is the first distinguisher for CubeHash compression function with more than 14 rounds

Preserving the confidentiality of digital images using a chaotic encryption scheme

Confidentiality of digital images is an important requirement for many multimedia applications and services. To maintain confidentiality, encryption of digital images is essential. Digital images are usually very large and encrypting such bulky data induces many performance overheads, which can be too expensive for real-time applications in resource constrained environments. In this paper, we propose a chaotic image encryption scheme which satisfies the need for both light-weightedness and security. To justify the security and efficiency, the new cipher was evaluated using a series of statistical tests. These tests included a visual testing and a histogram analysis, a randomness analysis, a correlation analysis, an entropy analysis and an image encryption quality analysis. Based on all analyses and experimental results, it is concluded that the proposed scheme is effective, efficient and trustworthy and therefore can be adopted for image encryption