Abstract:
Confusion and diffusion are the two main principles in
encryption. Confusion is a process that drastically changes data
from the input to the output. In order to make it right, we have
to make the relation between the key and cipher-text as complex
as possible. On the other hand, diffusion means that changing a
single character of the input will change many characters of the
output. In other words, we can say that the output bits should
depend on the input bits in a very complex way, so if we change
one bit in the plain-text, the cipher-text will change completely.
Many chaos-based algorithms were implemented with a chaotic
map called the Skew Tent Map (STM), which we address and
evaluate in this paper. Our proposed hybrid encryption scheme
combines both stream and block ciphering algorithms to achieve
the required level of security with the minimum encryption
time. The proposed chaos-based cryptosystem uses the STM as
a substitution based on a lookup table and STM as a generator
to change the byte position to achieve the required confusion
and diffusion effects. There is no need to have the inverse or
the reverse of the generator in our proposed cryptosystem. The
robustness of the proposed cryptosystem was proven by the
performance and security analysis, as well as the high encryption
speed (throughput).
