Abstract
Recently, an encryption technique depending on discrete dynamical chaotic maps and Brownian motion was offered. The authors of the understudy cryptosystem claim the security of encryption structure by some statistical analysis. We report cryptanalysis of a recently proposed scheme by using some cryptographic attacks. The attacks performed in this work are chosen-plaintext attack, known-plaintext attack, and chosen-ciphertext attack. The offered procedure is cryptanalyzed by taking just one chosen-plain image, one chosen-cipher image, and only one pair of plaintext and ciphertext, which shows the scheme's vulnerability. Moreover, we have offered an improved cryptosystem depending on the Basin chaotic map, Gingerbread man map, and Brownian motion, providing a robust security level.