Chaotic encryption algorithm based on alternant of stream cipher and block cipher

In recent years, a growing number of discrete chaotic cryptographic algorithms have been proposed. However, most of them encounter some problems such as the lack of robustness and security. In this paper, a new encryption algorithm is proposed, which encrypts the plaintext based on alternant of the stream cipher and block cipher. A pseudo-random number is used to control which encryption mode is chosen. Using this algorithm, multiple kinds of files (such as TXT, DOC, WMA, and JPEG) are encrypted and decrypted, and the security of the proposed cryptosystem is analyzed. The results show that the security of the cryptosystem is intensified and the proposed algorithm can resist differential attacks.