Secure image cryptosystem with unique key streams via hyper-chaotic system

•Cryptanalyzing Norouzi et al.'s scheme to demonstrate its security weaknesses.•Developing an attack scenario to break the Norouzi et al.'s cipher.•Proposing an advanced version of Norouzi et al.'s scheme to remedy its security weakness.•The proposed scheme resists several attacks such as known/chosen-plain-image attacks.•Results assure the effectiveness of the proposed image encryption scheme.

This paper cryptanalyses the hyper-chaotic image encryption scheme developed by Norouzi et al. and presents a chosen-plain-image attack scenario to reveal its generated key stream. The recovered key stream can be used to decrypt any future related cipher-image without having the secret key. In addition, the paper introduces an advanced version of the underlying image encryption scheme to overcome its security shortcomings. Specifically, the proposed cipher generates a unique key stream for each distinct plain-image based on its fingerprint. This thwarts the chosen-plain-image attacks and enhances the security level of the proposed scheme. Finally, the experimental results confirm the robustness of the proposed image cipher against different types of attacks.