Thesis Type: Postgraduate
Institution Of The Thesis: Kocaeli University, Teknoloji Fakültesi, Bilişim Sistemleri Mühendisliği, Turkey
Thesis Supervisor: Mehmet Yıldırım
Approval Date: 2022
Thesis Language: Turkish
Abstract:
Data security is an important issue in all types of communication, especially in
confidential data communications. Encryption of data, that is, cryptology, is one of the
classical methods to ensure the security of data. Encryption of data keeps the data content
confidential, but since the existence of the data is not confidential, it can be observed or
damaged by undesired persons. Steganography is the science that allows the existence of
data to be hidden.
Steganographic studies use media called carriers or covers to hide the existence of data.
Carrier media; can be video, audio, image, or program files. The media obtained by hiding
data to the carrier media is called stego media. In spatial domain image steganography,
the carrier media is digital image files. Data hiding operations are performed directly on
the pixel values of the carrier image. Many researchers have developed techniques in this
field and suggested techniques.
In this thesis, a new steganography technique was developed based on the least significant
bit displacement technique used in spatial domain image steganography. The proposed
technique uses the techniques of separating the carrier image into blocks and channel
selection, which are also available in the literature, for the secure transmission of data.
The security of the data, which is one of the important and basic criteria of steganography,
has been tried to be increased by selecting the channel with the genetic algorithm in the
block data and the security of the data has been ensured by the key generated by the
genetic algorithm. In practice, grayscale image files of five different sizes were used as
confidential data in order to hide data of different capacities on a fixed-size grayscale
carrier image. Instead of sequentially selecting the carrier image pixels in the classical
least significant bit technique, this selection is made with a genetic algorithm, preventing
the data from being easily retrieved without a key. As a result of the application, it has
been observed that both the security of confidential data can be increased compared to
the techniques in the literature and the presence of the data can be better hidden by
reducing the deterioration in the carrier image.