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خوارزمية جديدة لنظام اخفاء المعلومات == New Algorithm For A Steganography System
Author name:
مروة جليل محسن
Supervisor name:
اثير علاء صبري
General topic:
Electrical, Electronic and Communications Engineering
Specific topic:
Communications Engineering
Degree:
Master
University:
University of Technology - Electrical Engineering Department - Electronic Engineering Branch
Language:
English
University location:
Baghdad
First pages:
34T478 - p.pdf
Abstract:
This thesis presents a new steganographic algorithm for embedding encrypted secret image in grayscale and color images to provide high level security of data for communication over unsecured channels.The proposed algorithm combine the features of Cryptography and Steganography. The hidden secret message capacity, stego - image quality and security are three important conditions for data hiding technology. According to these requirements, an effective security protection with high hiding capacity steganographic algorithms are proposed based on frequency domain of the cover and the secret image.The proposed algorithm first analyzes the secret image into its frequency components using Discrete wavelet transform (DWT) , Wavelet packet transform(WPT) , Multiwavelet transform(MWT) , and slantlet transform(SLT) , respectively. Then the low frequencycomponent of the secret image is encrypted using Advanced encrypted standard (AES) method and then embedded in the insensitive mid and high sub - bands obtained from the cover image after applying these transformations (mentioned earlier) on it. The embedding method used in this thesis is LSB (Least significant bit ) method. The resulting stego image from different algorithms are then compared..The effectiveness of the proposed algorithm has been estimated by computing Mean square error (MSE) ,signal to noise ratio (SNR), Peak Signal to Noise Ratio (PSNR) and the capacity.The best algorithm is obtained by using 2level - DWT for cover image and 1level - DWT or WPT for secret image because the capacity of the hidden secret data and stego image quality are improved. The embedding image reaches to half the size of cover image at same time PSNR reach to 62 dB and MSE about 0.036 and this is better than many other existence algorithms.By both objective and subjective observations, the resultant stegoimage that will be transmitted does not draw any suspicion, so the main goal of steganography is achieved..The language used for testing the algorithms is MATLAB R2013a, with a computer of the following specification ; Processor : Intel(R) Core(TM) i5 CPU M430 @ 2.27GHz and RAM - 3GBytes.
