Breaking a novel image fusion encryption algorithm based on DNA sequence operation and hyper-chaotic system

Recently, a novel image fusion encryption algorithm based on DNA sequence operation and hyper-chaotic system was proposed. It was reported that the scheme can be broken with 4mn/3 +1 chosen plain-images and the corresponding cipher-images, where mn is the size of the plain-image. This paper re-evaluates the security of the encryption scheme and finds that the encryption scheme can be broken with less than ⌈ log 2(4mn)/2 ⌉ +1 chosen plain-images, even three in many cases. The effectiveness of the proposed chosen-plaintext attack is supported by theoretical analysis, and verified by experimental results.