一个四翼超混沌系统在图像加密技术中的应用

A Four-Winged Hyper-chaotic System and Its Application in Image Encryption

采用双重加密算法将一个能够产生真正的四翼混沌吸引子的四维超混沌系统应用于图像加密技术,系统的每一个方程里都含有一个三次的交叉乘积项,系统信号的频谱带宽也较宽,可以进一步提高密钥系统的安全性.一方面,经过双重加密后的明文与密文之间没有直接联系,无法通过选择特殊的明文、密文对的办法破解密钥序列;另一方面,在每一重加密过程中,明文与密文之间都含有非线性运算,能够更有效地抵御选择明文攻击.该算法将明文在任何位置像素值的影响扩散到了密文的所有像素,提高了密文对明文的敏感性,促进了复杂混沌系统在信息加密技术中的应用研究.

Using a dual encryption algorithm,the authors of this paper apply a four-dimensional chaotic system which can produce a true four-winged chaotic attractor to the image encryption technology.Each equation of the system contains a triple secant product and the frequency spectrum of its signals is quite wide,thus further improving the security of the encryption key.Through the dual encryption,no direct relationship exists between the plaintext and the ciphertext and,therefore,the encryption key can not be cracked by choosing a special pair of plaintext and ciphertext.On the other hand,in each course of encryption,there are nonlinear operations between the plaintext and the ciphertext,which can resist the attack from the plaintext more effectively.Every pixel value of the plaintext can influence all the pixel values of the ciphertext,which can improve the security of the encryption key and the sensibility of the ciphertext to the plaintext.