Secure communication based on synchronization of a unified chaotic system

Since chaotic signal has a broad spectrum and is noise like, it is suitable for information encryption. Chaotic encryption is superior to key-based encryption as its speed is almost unrelated with key length. This paper presents an improved secure communication algorithm based on a unified system. The algorithm is used for encrypting and decrypting both continuous signals and discrete signals such that of a digital image. Especially, it avoids eigenfrequency assumptions for transmitted signals. Theoretical proof and numerical simulations show its high secure level and feasibility.