Determination of the appropriate mask for hiding secure data on digital images

The need for information security is increasing day by day. The security of information is not only the security of personal information but also has a critical role in the communication of institutions and countries. Even in the case of war, the greatest weakness of the countries is that they cannot secure the information. Two important technical cryptography and steganography used in communicating the confidentiality and secure transmission of the message. The main purpose in cryptography is to prevent information from being accessed and decrypted by unauthorized persons. The main purpose of steganography studies is to prevent the hidden data from being recognized by unauthorized persons. Steganography is derived from Greek words, meaning "Covered Writing". In order to realize the basic purpose of the steganography methods, the environment in which information is to be hidden needs to be changed at least. Steganography media can be any of audio, video, video, or text files. In this thesis study, least significant bit method which is one of the methods of hiding information in digital imagery is examined. When least significant bit method is hidden, a new method of data hiding is proposed by creating optimum mask in order to minimize the changes occurring in the cover file and to make it difficult to obtain hidden data.