The Combination of Bit Matching-Based Steganography and DES Cryptography for Data Security

Abstract

This research discussed the combination of steganography and cryptography to secure data without changing the quality of cover medium. Steganographic method is used to match bit of the message with bit of the MSB image cover. Matching process is done by divide and conquer method. The result will be a bit indexposition, and then it will be encrypted using cryptographic DES (Data Encryption Standard). The input are text message, image, and key. The output is ciphertext bit index which can be used to secure the messages. To read the contents of the message, we require the same image cover and key.Outcomes of proposed method can be used to secure the data. The advantages of this method are the image quality will not change and the capacity of stored messages can be larger than the image. Acoording to the research, both grayscale and colorful images can be used as image cover, except the image contains 100% black and 100% white. Bit matching process on image which have much variety of color takes less time. The damage of messages due to the addition of “salt and pepper” noise starts from 0,0067 of MSE value and gaussian starts from MSE 0,00234.