Description:
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.
Description:
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.
Description:
Permutation is a commonly used primitive in multimedia (image/video) encryption schemes, and many permutation-only algorithms have been proposed in recent years for the protection of multimedia data. In permutation-only image ciphers, the entries of the image matrix are scrambled using a permutation mapping matrix which is built by a pseudo-random number generator. The literature on the cryptanalysis of image ciphers indicates that the permutation-only image ciphers are insecure against ciphertext-only attacks and/or known/chosenplaintext attacks. However, the previous studies have not been able to ensure the correct retrieval of the complete plaintext elements. In this paper, we revisited the previous works on cryptanalysis of permutation-only image encryption schemes and made the cryptanalysis work on chosen-plaintext attacks complete and more efficient. We proved that in all permutationonly image ciphers, regardless of the cipher structure, the correct permutation mapping is recovered completely by a chosenplaintext attack. To the best of our knowledge, for the first time, this paper gives a chosen-plaintext attack that completely determines the correct plaintext elements using a deterministic method. When the plain-images are of size M × N and with L different color intensities, the number n of required chosen plain-images to break the permutation-only image encryption algorithm is n = logL(MN). The complexity of the proposed attack is O (n · M N) which indicates its feasibility in a polynomial amount of computation time. To validate the performance of the proposed chosen-plaintext attack, numerous experiments were performed on two recently proposed permutation-only image/video ciphers. Both theoretical and experimental results showed that the proposed attack outperforms the state-of-theart cryptanalytic methods.
Description:
Permutation is a commonly used primitive in multimedia (image/video) encryption schemes, and many permutation-only algorithms have been proposed in recent years for the protection of multimedia data. In permutation-only image ciphers, the entries of the image matrix are scrambled using a permutation mapping matrix which is built by a pseudo-random number generator. The literature on the cryptanalysis of image ciphers indicates that the permutation-only image ciphers are insecure against ciphertext-only attacks and/or known/chosenplaintext attacks. However, the previous studies have not been able to ensure the correct retrieval of the complete plaintext elements. In this paper, we revisited the previous works on cryptanalysis of permutation-only image encryption schemes and made the cryptanalysis work on chosen-plaintext attacks complete and more efficient. We proved that in all permutationonly image ciphers, regardless of the cipher structure, the correct permutation mapping is recovered completely by a chosenplaintext attack. To the best of our knowledge, for the first time, this paper gives a chosen-plaintext attack that completely determines the correct plaintext elements using a deterministic method. When the plain-images are of size M × N and with L different color intensities, the number n of required chosen plain-images to break the permutation-only image encryption algorithm is n = logL(MN). The complexity of the proposed attack is O (n · M N) which indicates its feasibility in a polynomial amount of computation time. To validate the performance of the proposed chosen-plaintext attack, numerous experiments were performed on two recently proposed permutation-only image/video ciphers. Both theoretical and experimental results showed that the proposed attack outperforms the state-of-theart cryptanalytic methods.