What is Chaos Theory

The tremendous development in the field of telecommunication and computer technologies leads to the preference of transferring information as a digital data. In this transformation of information, cryptography helps in encrypting/decrypting digital data, so that intruders will not be able to sniff the highly confidential information. Most information is transferred as a digital image, where image encryption is done by scrambling the original pixels of the image, and hence, the correlation between the original pixel and scrambled pixel differs leading to confusion to unauthorized accesses. Chaotic image encryption is one of the recent technologies in cryptosystems, where a pseudorandom and irregular key is used for encryption/decryption, as the key suffers a great change if some initial conditions are altered, leading to highly secured transmission in the network. In this chapter, a detailed survey is conducted on chaotic image encryption using fractal function, in which fractal key is used for encryption and decryption of an image.