Dynamic Key Matrix of Hill Cipher Using Genetic Algorithm
This is a
technique in which we make the implementation of Hill cipher easy by using
genetic algorithm. In Hill cipher a matrix is designed to perform encryption
and decryption. We insert some integer number in the rows and columns of this
matrix. The wrong determinant result of this matrix
cannot be used in the process because while decryption it produces an incorrect
plain text. Genetic algorithms has the optimized way to finding the key which
is used for encryption and decryption on the Hill Cipher Algorithm. By implementing
this algorithm the searching of the key in Hill Cipher will be easily done in a
short time. Genetic Algorithm perform more efficient if it is combined with
is an arithmetic technique in cryptography that is why it uses a symmetric key
to convert plain text into cipher text. Symmetric key is a system that has the
same kind of keys in encryption and decryption. But we must have to inverse the
key before decrypting a cipher text into plain text. The major part in a matrix
that is used in Hill cipher is the multiplication between the matrix and the
inverse of a matrix. Now we will know about the genetic algorithm that what is
genetic algorithm and how it works. Genetic Algorithm is a computational
algorithm and basically this algorithm is built on the basis of genetic process
in the living organisms.
the following three main steps in Genetic Algorithm:
Selection is used to
recombine the population with the highest probability.
Crossover is a
genetic algorithm operator to mix the chromosomes with the extra chromosome
chosen to produce child chromosome from one generation to the next.
Mutation is a
genetic operator employed to maintain genetic diversity from one generation of
a population of genetic algorithm chromosomes to the next.
cipher there is a problem of finding the optimized key. In previous researches
key is obtained by trial and error method but this is not a good method of
finding a key. Here is a proper methodology of finding a key in Hill cipher so
doing this we have to apply genetic algorithm. In Hill Cipher every chromosome consists
of nine numbers. Each gene has a value “between” (0 to 255) which shows the
number of bytes. Since the ASCII value does not exceeds 255 so we cannot take
an integer as a modular expression. The matrix is transformed into
one-dimensional vector so we just search the ideal fitness which does not
contain equal value. Since the determinant is in the odd number, it is good for
Hill cipher. But in this case it will still to find until the determinant
reaches 1. The determinant has value 1 and it is suitable for the
Hill Cipher process. When the determinant is 1 it can bring the cipher text
back to the plain text and vice versa.
cipher which has 3*3 matrix in this matrix the searching key that has the
proper determinant takes time. If we perform this process by genetic algorithm
it will slow down the process of cryptography. Genetic algorithms greatly assist
the process of the encryption and the decryption on the Hill Cipher. This
process makes our problem solved and makes it easy and quick. It is a time
In this study, we conclude that the genetic algorithm has a great and
valuable contribution when combined with the Hill Cipher method.