Enhancement Of Pixel Value Ordering Based Data Hiding By Row Block Partition

The development of information and communication technology that support digital data transmission such as text, image, audio and video gives several effects. One of them is data security that becomes the main priority during the transmission process. Pixel-Value-Ordering (PVO) which one of data hiding methods can be implemented to achieve the requirement. It embeds data on maximum pixel and minimum pixel in a blok which is a part of the carrier image. However, PVO has capacity a problem, that only 2 bits per block can be hidden. To handle this problem, we propose a new approach by dividing blocks dinamically based on its complexity. These blocks are grouped into 4: smooth block, semi-smooth block, normal block and rough block. Using this approach, the stego capacity can be improved up to 2.6 times in average of previous method by keeping the quality stego more than 65 dB for all testing image

ENHANCEMENT OF PIXEL VALUE ORDERING BASED DATA HIDING BY ROW BLOCK PARTITION

The development of information and communication technology that support digital data transmission such as text, image, audio and video gives several effects. One of them is data security that becomes the main priority during the transmission process. Pixel-Value-Ordering (PVO) which one of data hiding methods can be implemented to achieve the requirement. It embeds data on maximum pixel and minimum pixel in a blok which is a part of the carrier image. However, PVO has capacity a problem, that only 2 bits per block can be hidden. To handle this problem, we propose a new approach by dividing blocks dinamically based on its complexity. These blocks are grouped into 4: smooth block, semi-smooth block, normal block and rough block. Using this approach, the stego capacity can be improved up to 2.6 times in average of  previous method by keeping the quality stego more than 65 dB for all testing image

Generalized PVO‐based dynamic block reversible data hiding for secure transmission using firefly algorithm

In this paper, we proposed a novel generalized pixel value ordering–based reversible data hiding using firefly algorithm (GPVOFA). The sequence of minimum and maximum number pixels value has been used to embed the secret data while prediction and modification are held on minimum, and the maximum number of pixel blocks is used to embed the secret data into multiple bits. The host image is divided into the size of noncoinciding dynamic blocks on the basis of firefly quadtree partition, whereas rough blocks are divided into a larger size; moreover, providing more embedding capacity used small flat blocks size and optimal location in the block to write the information. Our proposed method becomes able to embed large data into a host image with low distortion. The rich experimental results are better, as compared with related preceding arts

A DATA HIDING SCHEME BASED ON CHAOTIC MAP AND PIXEL PAIRS

Information security is one of the most common areas of study today. In the literature, there are many algorithms developed in the information security. The Least Significant Bit (LSB) method is the most known of these algorithms. LSB method is easy to apply however it is not effective on providing data privacy and robustness. In spite of all its disadvantages, LSB is the most frequently used algorithm in literature due to providing high visual quality. In this study, an effective data hiding scheme alternative to LSB, 2LSBs, 3LSBs and 4LSBs algorithms (known as xLSBs), is proposed. In this method, random numbers which are to be used as indices of pixels of the cover image are obtained from chaotic maps and data hiding process is applied on the values of these pixels by using modulo function. Calculated values are embedded in cover image as hidden data. Success of the proposed data hiding scheme is assessed by Peak Signal-to-Noise Ratio (PSNR), payload capacity and quality

Enhancing The Performance Of Digital Image Data Hiding Using Reduced Difference Expansion Technique And Constant Base Point

The last few decades have been marked by a rapid growth and significant enhancement of the internet infrastructures, i.e., the internet has become a broad network enabling many enterprises around the world to interact while sharing multimedia data. Nevertheless, this technology has brought many challenges related to securing private and sensitive information which has led to the application of cryptography technique as a mean for securing data by encrypting them. However, since the encrypted data can be seen by active and sophisticated intruders during the transmission, this may lead to its suspicion which can result in unauthorized access. Thereby, data hiding (which is also called information hiding) is another technique for securing commutation via the public network. Data hiding is one of the best and most challenging fields dealing with securing organizational sensitive information due to many factors such as identity theft, information phishing, user privacy, network policy violation, contents and copyright protection. It is performed by utilizing some carriers to conceal private information which is further extracted later to verify and validate the genuineness. Digital steganography has been recognized among the recent and most popular data hiding techniques. Steganography is the practice of concealing confidential information in the codes that make up the digital files. Such digital files can be an image, audio, video, and text. Different from cryptography, however, steganography provides security by disguising the presence of communication. It originates from the concept that if the communication is visible, the suspicion or attack is obvious. Hence, the main goal is to always disguise the presence of the hidden confidential data. Recently, various data iv hiding methods based on digital image steganography have been already suggested by several researchers around the globe. The main goal was to improve the security, embedding capacity and the quality of the stego image. However, research have shown that there is still a challenge to achieve a good visual quality of the stego media while preserving a good embedding capacity. In this direction, this study aims at proposing a new data hiding approach that enhances the quality of the stego image and the embedding capacity. That is, the suggested approach enhances the existing data hiding methods by utilizing pixel block, constant base point for each pixel block and the reduced difference expansion scheme (RDE-scheme) for grayscale digital images. Accordingly, the suggested enhancement is detailed as follows. First, the existing reduced difference expansion scheme (RDE-scheme) for reducing the difference values is enhanced in order to get possible small values to be used while concealing the secret data into the cover image. The main objective behind this enhancement is to allow data to be concealed while preserving the quality of the stego image. Notice that the suggested RDE-scheme does not only enhance the quality but also it solves the problem of underflow and overflow. The underflow is encountered when the pixel value in the stego image is below 0 (Pixel value < 0) while the overflow occurs when it is greater than 255 (Pixel value > 255). Second, the new constant base point for each pixel block is chosen differently for the sake of increasing the visual quality of the stego image. Third, we have adjusted the size of the pixel block which achieves a high embedding capacity while distorting the cover media from quad of quad (4 × 4 ) to quad, block of size 2 by 2 (2 × 2). Besides, the effect of varying the size of the secret data with respect to the quality of the stego image is also investigated throughout this study. Overall, based on the experimental results, good visual quality of the stego image which is evaluated by measuring the peak signal-to-noise ratio (PSNR) and good embedding capacity (measured in bits) are yielded compared to the previous approach, i.e., the proposed method is effective in terms of maintaining both visual quality of the stego image and the embedding capacity. Index terms— Data hiding, information security, reduced difference expansion, digital steganography, cover image, stego image, confidential data =================================================================================================== Beberapa dekade terakhir internet telah menjadi jaringan luas yang memungkinkan banyak perusahaan di seluruh dunia untuk berinteraksi sambil berbagi data multimedia. Ini merupakan tanda bahwa infrastruktur internet telah tumbuh dan berkembang secara signifikan. Namun, teknologi ini memiliki banyak tantangan dalam hal pengamanan informasi yang bersifat sensitif dan pribadi sehingga mendorong penerapan teknik kriptografi untuk mengamankan data dengan cara mengenkripsinya. Teknik kriptografi memiliki kekurangan yaitu hasil enkripsi dapat dilihat oleh penyusup (intruders) selama transmisi sehingga menyebabkan kecurigaan yang berakibat pada tindakan akses yang bersifat ilegal. Untuk mengurangi hal ini, data hiding dapat dimanfaatkan untuk mengamankan informasi tersebut. Data hiding adalah salah satu teknik terbaik untuk mendapatkan data tetapi memiliki banyak tantangan permasalahan seperti pencurian identitas, phising, pelanggaran kebijakan jaringan dan hak cipta. Untuk mendapatkan kemanan data, data hiding memanfaatkan beberapa media untuk menyembunyikan informasi dan dapat diekstrak untuk memverifikasi keasliannya. Salah satu teknik data hiding yang paling terkenal adalah steganografi digital. Teknik ini menyembunyikan informasi rahasia kedalam file digital seperti citra digital, audio, video dan teks. Berbeda dengan kriptografi, steganografi memberikan keamanan informasi dengan menyamarkannya dalam file digital. Penyebab digunakannya tindakan ini adalah jika komunikasi terlihat maka akan mengundang kecurigaan yang mengakibatkan terjadi serangan seperti yang dijelaskan sebelumnya. Oleh karena itu, tujuan utama dari teknik ini adalah menyamarkan informasi rahasia dengan vi menyembunyikannya kedalam file yang digunakan. Akhir-akhir ini, beberapa teknik data hiding dengan menggunakan citra digital telah banyak dikembangkan oleh beberapa peneliti di seluruh dunia. Tujuan utama mereka adalah untuk meningkatkan keamanan, kapasitas penyisipan dan kualitas dari citra stego. Sampai saat ini, banyak penelitian yang menunjukkan bahwa masih menjadi tantangan untuk mendapatkan kualitas media stego yang baik dengan kapasitas penyisipan yang tinggi. Dengan maksud yang sama, penelitian ini mengusulkan konsep pendekatan baru dalam hal data hiding yang dapat meningkatkan kualitas dan kapasitas dari citra stego. Pendekatan tersebut dilakukan dengan cara meningkatkan metode data hiding yang sudah ada dengan memanfaatkan blok piksel, penentuan base point yang konsisten untuk masing-masing blok dan mereduksi difference expansion untuk citra abu-abu. Rincian dari pendekatan tersebut adalah sebagai berikut. Pertama, skema reduksi difference expansion (RDE) ditingkatkan untuk mendapatkan nilai terkecil yang akan digunakan dalam penyembunyian data kedalam citra carrier. Tujuannya adalah memungkinkan data dapat disisipkan dengan tetap menjaga kualitas citra stego tetap baik. Perlu diketahui bahwa usulan skema RDE tidak hanya meningkatkan kualitas tetapi juga menyelesaikan masalah overflow dan underflow. Underfow merupakan kondisi piksel dalam citra stego bernilai kurang dari 0 sedangkan overflow terjadi ketika nilai piksel melebihi 255. Kedua, base-point yang bersifat konstan untuk masing-masing blok piksel akan dipilih secara berbeda untuk dapat meningkatkan kualitas visual dari citra stego. Ketiga, kami mengatur ukuran blok dari quad of quad (4x4) yang memiliki kualitas citra stego kurang baik menjadi 2x2. Hal lain yang kami lakukan adalah mengetahui efek dari besar ukuran data yang digunakan dalam proses penyisipan. Secara keseluruhan, berdasarkan hasil eksperimen, usulan pendekatan ini memiliki kemampuan yang lebih baik dibandingkan dengan penelitian sebelumnya yang ditandai dengan kapasitas penyisipan yang lebih tinggi dan kualitas visual citra stego yang baik yang diukur menggunakan metode signal-to-noise ratio (PSNR)

Digital rights management techniques for H.264 video

This work aims to present a number of low-complexity digital rights management (DRM) methodologies for the H.264 standard. Initially, requirements to enforce DRM are analyzed and understood. Based on these requirements, a framework is constructed which puts forth different possibilities that can be explored to satisfy the objective. To implement computationally efficient DRM methods, watermarking and content based copy detection are then chosen as the preferred methodologies. The first approach is based on robust watermarking which modifies the DC residuals of 4×4 macroblocks within I-frames. Robust watermarks are appropriate for content protection and proving ownership. Experimental results show that the technique exhibits encouraging rate-distortion (R-D) characteristics while at the same time being computationally efficient. The problem of content authentication is addressed with the help of two methodologies: irreversible and reversible watermarks. The first approach utilizes the highest frequency coefficient within 4×4 blocks of the I-frames after CAVLC en- tropy encoding to embed a watermark. The technique was found to be very effect- ive in detecting tampering. The second approach applies the difference expansion (DE) method on IPCM macroblocks within P-frames to embed a high-capacity reversible watermark. Experiments prove the technique to be not only fragile and reversible but also exhibiting minimal variation in its R-D characteristics. The final methodology adopted to enforce DRM for H.264 video is based on the concept of signature generation and matching. Specific types of macroblocks within each predefined region of an I-, B- and P-frame are counted at regular intervals in a video clip and an ordinal matrix is constructed based on their count. The matrix is considered to be the signature of that video clip and is matched with longer video sequences to detect copies within them. Simulation results show that the matching methodology is capable of not only detecting copies but also its location within a longer video sequence. Performance analysis depict acceptable false positive and false negative rates and encouraging receiver operating charac- teristics. Finally, the time taken to match and locate copies is significantly low which makes it ideal for use in broadcast and streaming applications

Peningkatan Kinerja Prediction Error Expansion dalam Data Hiding dengan Mereduksi Error Expansion dan Mengelompokkan Nilai Piksel Secara Adaptif

Pertukaran informasi saat ini semakin mudah karena perkembangan teknologi informasi dan komunikasi yang semakin pesat. Kondisi ini terbukti dengan meningkatnya penggunaan IP global sebesar 88,7 EB (exabytes) perbulan pada tahun 2016. Peningkatan tersebut menjadikan keamanan informasi sebagai salah satu kebutuhan terpenting untuk melindungi data-data sensitif misalnya data finansial perusahaan atau data keamanan negara. Keamanan dari data sensitif dapat diperoleh menggunakan metode bernama data hiding. Teknik ini melindungi data dengan menyisipkannya kedalam sebuah objek (carrier) seperti citra digital. Algoritma matematis yang digunakan pada data hiding akan memodifikasi piksel pada carrier sehingga mendapatkan nilai baru. Modifikasi yang dilakukan sebaiknya menjaga agar carrier tidak berubah terlalu signifikan dan dapat menyediakan kapasitas penyembunyian data yang besar. Kebutuhan ini yang mendorong algoritma matematis pada data hiding terus dikembangkan. Salah satu algoritma matematis untuk data hiding adalah prediction error expansion (PEE). Metode ini menyisipkan data kedalam nilai prediksi perubahan piksel (expanded prediction error). PEE kemudian dikembangkan lebih lanjut dalam hal pemilihan piksel referensi dan penetuan tipe blok pada carrier. Namun pengembangan yang telah diusulkan belum memanfaatkan blok secara maksimal. Dalam satu blok, jumlah pesan yang mampu disisipkan hanya berkisar antara 2-6 bit saja. Salah satu cara yang dapat digunakan untuk mengatasi masalah tersebut adalah mengelompokkan piksel bernilai mirip secara adaptif dan menyisipkan 2 bit data sekaligus dalam sebuah piksel tanpa menggunakan konsep multi-layer embedding. Untuk menjaga agar perubahan nilai tidak terlalu besar, diusulkan metode reduksi pada nilai expanded prediction error. Berdasarkan hasil pengujian, metode yang diusulkan mampu meningkatkan kualitas dan kapasitas citra stego dengan rata-rata sebesar 4,257 dB dan 156.776 bit. =============================================================================================================== Today, the exchange of information is easier because of the rapid development of information and communication technology. This condition is proven by the increasing of the use of global IP of 88,7 EB (exabytes) per month in 2016. This increasement makes information security be the one of most important requirement in securing sensitive data such as corporate financial data or national security data. The security of sensitive data can be achieved by using a technique called data hiding. One of data hiding technique is steganography that embeds data using mathematical algorithms into multimedia object (e.g. digital image, video, audio) called carrier. The mathematical algorithm modifies the pixel values in the digital image. The modification should not change the carrier image significantly and provide large embedding capacity. This develop requirement makes algorithms that used in data hiding technique is developed continously. One of the mathematical algorithms for data hiding is prediction error expansion (PEE). It embeds data into predicted pixel value (expanded prediction error). PEE was developed further in terms of reference pixel selection and block type determination on carrier images. However, the existing PEE algorithm has no use the block maximally. In a block, the existing PEE algorithm only can embed 2-6 bits of data. Therefore, it is necessary to develop the utilization of blocks. One of methods that can be used is grouping similar pixel value adaptively and embedding 2-bits of data into a block without using multi-layer embedding concept. Additionally, to keep the pixel value from being changed significantly while hiding data, the expanded prediction error value will be reduced. Based on experiment, it shows that the proposed method can improve quality and capacity of stego image by an average of 4,257 dB and 156.776 bits

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

Privacy-preserving information hiding and its applications

The phenomenal advances in cloud computing technology have raised concerns about data privacy. Aided by the modern cryptographic techniques such as homomorphic encryption, it has become possible to carry out computations in the encrypted domain and process data without compromising information privacy. In this thesis, we study various classes of privacy-preserving information hiding schemes and their real-world applications for cyber security, cloud computing, Internet of things, etc. Data breach is recognised as one of the most dreadful cyber security threats in which private data is copied, transmitted, viewed, stolen or used by unauthorised parties. Although encryption can obfuscate private information against unauthorised viewing, it may not stop data from illegitimate exportation. Privacy-preserving Information hiding can serve as a potential solution to this issue in such a manner that a permission code is embedded into the encrypted data and can be detected when transmissions occur. Digital watermarking is a technique that has been used for a wide range of intriguing applications such as data authentication and ownership identification. However, some of the algorithms are proprietary intellectual properties and thus the availability to the general public is rather limited. A possible solution is to outsource the task of watermarking to an authorised cloud service provider, that has legitimate right to execute the algorithms as well as high computational capacity. Privacypreserving Information hiding is well suited to this scenario since it is operated in the encrypted domain and hence prevents private data from being collected by the cloud. Internet of things is a promising technology to healthcare industry. A common framework consists of wearable equipments for monitoring the health status of an individual, a local gateway device for aggregating the data, and a cloud server for storing and analysing the data. However, there are risks that an adversary may attempt to eavesdrop the wireless communication, attack the gateway device or even access to the cloud server. Hence, it is desirable to produce and encrypt the data simultaneously and incorporate secret sharing schemes to realise access control. Privacy-preserving secret sharing is a novel research for fulfilling this function. In summary, this thesis presents novel schemes and algorithms, including: • two privacy-preserving reversible information hiding schemes based upon symmetric cryptography using arithmetic of quadratic residues and lexicographic permutations, respectively. • two privacy-preserving reversible information hiding schemes based upon asymmetric cryptography using multiplicative and additive privacy homomorphisms, respectively. • four predictive models for assisting the removal of distortions inflicted by information hiding based respectively upon projection theorem, image gradient, total variation denoising, and Bayesian inference. • three privacy-preserving secret sharing algorithms with different levels of generality