In this paper we will first discuss cryptography
from a historical point of view in order to
understand the motivation behind this science. We
will discuss the earliest form of cryptography
before fast forwarding to the current modem forms
of cryptography.
We will then mention issues surrounding current
modem cryptographic methods before introducing
chaos based cryptography. The relationship
between chaos and cryptography makes it natural
to employ chaotic systems to design new
cryptosystems. It is based on the facts that chaotic
signals are usually noise-like and chaotic systems
are very sensitive to initial conditions. Their
sensitivity to initial conditions and their spreading
out of trajectories over the whole interval seems to
be a model that satisfies the classic Shannon
requirements of confusion and diffusion [1] From 1989 onwards, many different chaotic
encryption systems have been proposed. The most
celebrated chaotic cryptosystem is based on the
ergodicity property of chaotic maps [2] and has
received more and more attentions in the past
literature [3-17]. Introduced by Baptista in 1998, it
is able to produce different ciphers for the same
plaintext.
It was cracked by Alvarez in 2003 via the one-time
pad attack. In 2008, M.R.K.Ariffin and
M.S.M.Noorani [22] engaged the attack and
devised a counter measure against it
