Securing medical images is a great challenge to protect medical privacy. An image encryption model founded on a complex chaos-based Pseudorandom Number Generator (PRNG) and Modified Advanced Encryption Standard (MAES) is put forward in this paper. Our work consists of the following three main points. First, we propose the use of a complex PRNG based on two different chaotic systems which are the 2D Logistic map in a complex set and Henons system in the key generation procedure. Second, in the MAES 128bits, the subbytes operation is performed using four different S-boxes for more complexity. Third, both shift-rows and mix-columns transformations are eliminated and replaced with a random permutation method which increases the complexity. More importantly, only four rounds of encryption are performed in a loop that reduces significantly the execution time. The overall system is implemented on the Altera Cyclone III board, which is completed with an SD card interface for medical image storage and a VGA interface for image display. The HPS software runs on μClinux and is used to control the FPGA encryption-decryption algorithm and image transmission. Experimental findings prove that the propounded map used has a keyspace sufficiently large and the proposed image encryption algorithm augments the entropy of the ciphered image compared to the AES standard and reduces the complexity time by 97. The power consumption of the system is 136.87mw and the throughput is 1.34 Gbit/s. The proposed technique is compared to recent image cryptosystems including hardware performances and different security analysis properties, such as randomness, sensitivity, and correlation of the encrypted images and results prove that our cryptographic algorithm is faster, more efficient, and can resist any kind of attacks.

Securing multimedia applications becomes a major challenge with the violation of the information increasing currently. In this paper, a novel method for color image encryption is proposed. The procedure of encryption is performed using cooperation between Elliptic Curve Cryptography (ECC) and the Advanced Encryption Standard (AES) with CTR (Counter) mode. In the cryptographic system, we have proposed to take advantage of the Elliptic Curve Random Generator to generate a sequence of arbitrary numbers based on the curve. The random generation step is founded on the public key sharing and a changing point G. Then, the AES-CTR is performed to these sequences using arbitrary keys for image encryption. The use of the AES alongside greatly distributed random results an interesting encryption method. Security analysis is successfully performed and our experiments prove that the suggested technique provides the basis of cryptography with more simplicity and correctness.

With the growth of Computer Network and Communication Technology, medical images need to be exchanged safely by public communication networks. High security and high speed of image transmission become much more important. In this paper, an improved AES-ECC hybrid cryptosystem is proposed to be implemented in the DE2-115 board combining benefits of the Advanced Encryption Standard (AES) with CTR mode to accelerate data encryption and the Elliptic curve cryptography (ECC) to secure the exchange for symmetric session key. To reduce the execution time in the encryption process, both shift rows and mix columns operation in the AES are removed and replaced with a random permutation. Only six rounds of encryption are performed in a loop. In the ECC, both point addition and point doubling are optimized to use only two reused multipliers. Our hardware implementation on ALTERA CYCLONE IV.E FPGA, uses only 14% of logic elements achieving a maximum frequency of 236 MHz and consumed 1.35 mw of thermal power dissipation. Security analysis is successfully performed and our experiments prove that the suggested technique provides the basis of cryptography with more simplicity and correctness.