18 research outputs found
Data Hiding in Digital Video
With the rapid development of digital multimedia technologies, an old method which is called steganography has been sought to be a solution for data hiding applications such as digital watermarking and covert communication. Steganography is the art of secret communication using a cover signal, e.g., video, audio, image etc., whereas the counter-technique, detecting the existence of such as a channel through a statistically trained classifier, is called steganalysis.
The state-of-the art data hiding algorithms utilize features; such as Discrete Cosine Transform (DCT) coefficients, pixel values, motion vectors etc., of the cover signal to convey the message to the receiver side. The goal of embedding algorithm is to maximize the number of bits sent to the decoder side (embedding capacity) with maximum robustness against attacks while keeping the perceptual and statistical distortions (security) low. Data Hiding schemes are characterized by these three conflicting requirements: security against steganalysis, robustness against channel associated and/or intentional distortions, and the capacity in terms of the embedded payload. Depending upon the application it is the designer\u27s task to find an optimum solution amongst them.
The goal of this thesis is to develop a novel data hiding scheme to establish a covert channel satisfying statistical and perceptual invisibility with moderate rate capacity and robustness to combat steganalysis based detection. The idea behind the proposed method is the alteration of Video Object (VO) trajectory coordinates to convey the message to the receiver side by perturbing the centroid coordinates of the VO. Firstly, the VO is selected by the user and tracked through the frames by using a simple region based search strategy and morphological operations. After the trajectory coordinates are obtained, the perturbation of the coordinates implemented through the usage of a non-linear embedding function, such as a polar quantizer where both the magnitude and phase of the motion is used. However, the perturbations made to the motion magnitude and phase were kept small to preserve the semantic meaning of the object motion trajectory.
The proposed method is well suited to the video sequences in which VOs have smooth motion trajectories. Examples of these types could be found in sports videos in which the ball is the focus of attention and exhibits various motion types, e.g., rolling on the ground, flying in the air, being possessed by a player, etc. Different sports video sequences have been tested by using the proposed method. Through the experimental results, it is shown that the proposed method achieved the goal of both statistical and perceptual invisibility with moderate rate embedding capacity under AWGN channel with varying noise variances. This achievement is important as the first step for both active and passive steganalysis is the detection of the existence of covert channel.
This work has multiple contributions in the field of data hiding. Firstly, it is the first example of a data hiding method in which the trajectory of a VO is used. Secondly, this work has contributed towards improving steganographic security by providing new features: the coordinate location and semantic meaning of the object
Secured Mechanism Towards Integrity of Digital Images Using DWT, DCT, LSB and Watermarking Integrations
"Watermarking" is one method in which digital information is buried in a carrier signal;
the hidden information should be related to the carrier signal. There are many different types of
digital watermarking, including traditional watermarking that uses visible media (such as snaps,
images, or video), and a signal may be carrying many watermarks. Any signal that can tolerate
noise, such as audio, video, or picture data, can have a digital watermark implanted in it. A digital
watermark must be able to withstand changes that can be made to the carrier signal in order to
protect copyright information in media files. The goal of digital watermarking is to ensure the
integrity of data, whereas steganography focuses on making information undetectable to humans.
Watermarking doesn't alter the original digital image, unlike public-key encryption, but rather
creates a new one with embedded secured aspects for integrity. There are no residual effects of
encryption on decrypted documents. This work focuses on strong digital image watermarking
algorithms for copyright protection purposes. Watermarks of various sorts and uses were
discussed, as well as a review of current watermarking techniques and assaults. The project shows
how to watermark an image in the frequency domain using DCT and DWT, as well as in the spatial
domain using the LSB approach. When it comes to noise and compression, frequency-domain
approaches are far more resilient than LSB. All of these scenarios necessitate the use of the original
picture to remove the watermark. Out of the three, the DWT approach has provided the best results.
We can improve the resilience of our watermark while having little to no extra influence on image
quality by embedding watermarks in these places.
Recent Advances in Signal Processing
The signal processing task is a very critical issue in the majority of new technological inventions and challenges in a variety of applications in both science and engineering fields. Classical signal processing techniques have largely worked with mathematical models that are linear, local, stationary, and Gaussian. They have always favored closed-form tractability over real-world accuracy. These constraints were imposed by the lack of powerful computing tools. During the last few decades, signal processing theories, developments, and applications have matured rapidly and now include tools from many areas of mathematics, computer science, physics, and engineering. This book is targeted primarily toward both students and researchers who want to be exposed to a wide variety of signal processing techniques and algorithms. It includes 27 chapters that can be categorized into five different areas depending on the application at hand. These five categories are ordered to address image processing, speech processing, communication systems, time-series analysis, and educational packages respectively. The book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity
Sensor Data Integrity Verification for Real-time and Resource Constrained Systems
Sensors are used in multiple applications that touch our lives and have become an integral part of modern life. They are used in building intelligent control systems in various industries like healthcare, transportation, consumer electronics, military, etc. Many mission-critical applications require sensor data to be secure and authentic. Sensor data security can be achieved using traditional solutions like cryptography and digital signatures, but these techniques are computationally intensive and cannot be easily applied to resource constrained systems. Low complexity data hiding techniques, on the contrary, are easy to implement and do not need substantial processing power or memory. In this applied research, we use and configure the established low complexity data hiding techniques from the multimedia forensics domain. These techniques are used to secure the sensor data transmissions in resource constrained and real-time environments such as an autonomous vehicle. We identify the areas in an autonomous vehicle that require sensor data integrity and propose suitable water-marking techniques to verify the integrity of the data and evaluate the performance of the proposed method against different attack vectors. In our proposed method, sensor data is embedded with application specific metadata and this process introduces some distortion. We analyze this embedding induced distortion and its impact on the overall sensor data quality to conclude that watermarking techniques, when properly configured, can solve sensor data integrity verification problems in an autonomous vehicle.Ph.D.College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttp://deepblue.lib.umich.edu/bitstream/2027.42/167387/3/Raghavendar Changalvala Final Dissertation.pdfDescription of Raghavendar Changalvala Final Dissertation.pdf : Dissertatio
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Combined robust and fragile watermarking algorithms for still images. Design and evaluation of combined blind discrete wavelet transform-based robust watermarking algorithms for copyright protection using mobile phone numbers and fragile watermarking algorithms for content authentication of digital still images using hash functions.
This thesis deals with copyright protection and content authentication for still images. New blind
transform domain block based algorithms using one-level and two-level Discrete Wavelet Transform
(DWT) were developed for copyright protection. The mobile number with international code is used as
the watermarking data. The robust algorithms used the Low-Low frequency coefficients of the DWT to
embed the watermarking information. The watermarking information is embedded in the green channel of
the RGB colour image and Y channel of the YCbCr images. The watermarking information is scrambled
by using a secret key to increase the security of the algorithms. Due to the small size of the watermarking
information comparing to the host image size, the embedding process is repeated several times which
resulted in increasing the robustness of the algorithms. Shuffling process is implemented during the multi
embedding process in order to avoid spatial correlation between the host image and the watermarking
information. The effects of using one-level and two-level of DWT on the robustness and image quality
have been studied. The Peak Signal to Noise Ratio (PSNR), the Structural Similarity Index Measure
(SSIM) and Normalized Correlation Coefficient (NCC) are used to evaluate the fidelity of the images.
Several grey and still colour images are used to test the new robust algorithms. The new algorithms
offered better results in the robustness against different attacks such as JPEG compression, scaling, salt
and pepper noise, Gaussian noise, filters and other image processing compared to DCT based algorithms.
The authenticity of the images were assessed by using a fragile watermarking algorithm by using hash
function (MD5) as watermarking information embedded in the spatial domain. The new algorithm
showed high sensitivity against any tampering on the watermarked images. The combined fragile and
robust watermarking caused minimal distortion to the images. The combined scheme achieved both the
copyright protection and content authentication
Recent Trends in Communication Networks
In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges
Engineering Education and Research Using MATLAB
MATLAB is a software package used primarily in the field of engineering for signal processing, numerical data analysis, modeling, programming, simulation, and computer graphic visualization. In the last few years, it has become widely accepted as an efficient tool, and, therefore, its use has significantly increased in scientific communities and academic institutions. This book consists of 20 chapters presenting research works using MATLAB tools. Chapters include techniques for programming and developing Graphical User Interfaces (GUIs), dynamic systems, electric machines, signal and image processing, power electronics, mixed signal circuits, genetic programming, digital watermarking, control systems, time-series regression modeling, and artificial neural networks
Design of 2D discrete cosine transform using CORDIC architectures in VHDL
The Discrete Cosine Transform is one of the most widely transform techniques in digital signal processing. In addition, this is also most computationally intensive transforms which require many multiplications and additions. Real time data processing necessitates the use of special purpose hardware which involves hardware efficiency as well as high throughput. Many DCT algorithms were proposed in order to achieve high speed DCT. Those architectures which involves multipliers, for example Chen’s algorithm has less regular architecture due to complex routing and requires large silicon area. On the other hand, the DCT architecture based on distributed arithmetic (DA) which is also a multiplier less architecture has the inherent disadvantage of less throughputs because of the ROM access time and the need of accumulator. Also this DA algorithm requires large silicon area if it requires large ROM size. Systolic array architecture for the real-time DCT computation may have the large number of gates and clock skew problem. The other ways of implementation of DCT which involves in multiplierless, thus power efficient and which results in regular architecture and less complicated routing, consequently less area, simultaneously lead to high throughput. So for that purpose CORDIC seems to be a best solution. CORDIC offers a unified iterative formulation to efficiently evaluate the rotation operation. This thesis presents the implementation of 2D Discrete Cosine Transform (DCT) using the Angle Recoded (AR) Cordic algorithm, the new scaling less CORDIC algorithm and the conventional Chen’s algorithm which is multiplier dependant algorithm. The 2D DCT is implemented by exploiting the Separability property of 2D Discrete Cosine Transform. Here first one dimensional DCT is designed first and later a transpose buffer which consists of 64 memory elements, fully pipelined is designed. Later all these blocks are joined with the help of a controller element which is a mealy type FSM which produces some status signals also. The three resulting architectures are all well synthesized in Xilinx 9.1ise, simulated in Modelsim 5.6f and the power is calculated in Xilinx Xpower. Results prove that AR Cordic algorithm is better than Chen’s algorithm, even the new scaling less CORDIC algorithm
Active FPGA Security through Decoy Circuits
Field Programmable Gate Arrays (FPGAs) based on Static Random Access Memory (SRAM) are vulnerable to tampering attacks such as readback and cloning attacks. Such attacks enable the reverse engineering of the design programmed into an FPGA. To counter such attacks, measures that protect the design with low performance penalties should be employed. This research proposes a method which employs the addition of active decoy circuits to protect SRAM FPGAs from reverse engineering. The effects of the protection method on security, execution time, power consumption, and FPGA resource usage are quantified. The method significantly increases the security of the design with only minor increases in execution time, power consumption, and resource usage. For the circuits used to characterize the method, security increased to more than one million times the original values, while execution time increased to at most 1.2 times, dynamic power consumption increased to at most two times, and look-up table usage increased to at most seven times the original values. These are reasonable penalties given the size and security of the modified circuits. The proposed design protection method also extends to FPGAs based on other technologies and to Application-Specific Integrated Circuits (ASICs). In addition to the design methodology proposed, a new classification of tampering attacks and countermeasures is presented