Um novo algoritmo de criptografia de alto desempenho baseado em modelos caóticos

Abstract

Nowadays, the internet is the main channel for communication between two parties. Since the internet is a public channel, the importance of cryptography to protect the communication is increased. The most commonly shared archives are images, for which traditional ciphers are not suitable due to large file sizes and high computational cost. In this context, chaos theory surges as a promising alternative for image encryption due to its sensibility to initial conditions, leading to the development of many chaotic ciphers for image encryption. Initially, chaotic ciphers were unsafe, being broken by chosen plain text attacks, as there was no relation between the chaotic sequences generated and the original plain image, but in recent years, this relation has been established and thus the security has improved markedly. However, from the performance standpoint, chaotic ciphers can be improved with a better choice of chaotic systems coupled with small architecture adjustments. This work starts first with a comparison of chaotic systems made to choose the one that conduces to the highest performance of the cipher, and then, three versions of the new cipher are proposed one with separate permutation-diffusion, other with simultaneous, and the final version for telemedical applications. Extensive tests made show that the cipher is secure against various forms of attacks, such as statistical, differential, noise, occlusion and chosen-plaintext, while also having superior performance to other works in literature.