New method of improving the security of the hyperchaotic cryptosystem

In chaotic cryptosystems, using (very) high dimensional chaotic attractors for encrypting a given message maybe can improve the privacy of chaotic encoding. A kind of hyperchaotic systems are studied by using some classical methods. The results show that for improving the security of the chaotic cryptosystems, besides the high dimension, the sub-Nyquist sampling interval (SI) is also necessary. Then, we verify this result using the methods of time series analysis.