Performance trade-offs of hybrid cryptosystem for medical images encryption - decryption
Amal Hafsa, Jihene Malek, Mohsen Machhout · 2021
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.