Generation and Realization of Digital Chaotic Key Sequence Based on Double K-L Transform

Chaotic special properties make the chaotic encryption technology be an important research field of information science and technology. However, as digital chaos is affected by the limited precision of computer, chaotic system properties present degradation—short periodicity of output sequence. This paper proposes a double K-L (Karhunen-Loeve) transform method for Logistic 0/1 sequence, and then analyzes autocorrelation, period, complexity and frequency spectrum. Simulation results show that this method can effectively improve the complexity and the length selection of key sequence. Moreover, it can also increase the period of Logistic sequence in wider range, which makes up the short periodicity phenomenon of digital chaotic sequence and makes digital chaotic key sequence be applied safely in encryption system.