Secure and efficient storage of multimedia: content in public cloud environments using joint compression and encryption

The Cloud Computing is a paradigm still with many unexplored areas ranging from the technological component to the de nition of new business models, but that is revolutionizing the way we design, implement and manage the entire infrastructure of information technology. The Infrastructure as a Service is the delivery of computing infrastructure, typically a virtual data center, along with a set of APIs that allow applications, in an automatic way, can control the resources they wish to use. The choice of the service provider and how it applies to their business model may lead to higher or lower cost in the operation and maintenance of applications near the suppliers. In this sense, this work proposed to carry out a literature review on the topic of Cloud Computing, secure storage and transmission of multimedia content, using lossless compression, in public cloud environments, and implement this system by building an application that manages data in public cloud environments (dropbox and meocloud). An application was built during this dissertation that meets the objectives set. This system provides the user a wide range of functions of data management in public cloud environments, for that the user only have to login to the system with his/her credentials, after performing the login, through the Oauth 1.0 protocol (authorization protocol) is generated an access token, this token is generated only with the consent of the user and allows the application to get access to data/user les without having to use credentials. With this token the framework can now operate and unlock the full potential of its functions. With this application is also available to the user functions of compression and encryption so that user can make the most of his/her cloud storage system securely. The compression function works using the compression algorithm LZMA being only necessary for the user to choose the les to be compressed. Relatively to encryption it will be used the encryption algorithm AES (Advanced Encryption Standard) that works with a 128 bit symmetric key de ned by user. We build the research into two distinct and complementary parts: The rst part consists of the theoretical foundation and the second part is the development of computer application where the data is managed, compressed, stored, transmitted in various environments of cloud computing. The theoretical framework is organized into two chapters, chapter 2 - Background on Cloud Storage and chapter 3 - Data compression. Sought through theoretical foundation demonstrate the relevance of the research, convey some of the pertinent theories and input whenever possible, research in the area. The second part of the work was devoted to the development of the application in cloud environment. We showed how we generated the application, presented the features, advantages, and safety standards for the data. Finally, we re ect on the results, according to the theoretical framework made in the rst part and platform development. We think that the work obtained is positive and that ts the goals we set ourselves to achieve. This research has some limitations, we believe that the time for completion was scarce and the implementation of the platform could bene t from the implementation of other features.In future research it would be appropriate to continue the project expanding the capabilities of the application, test the operation with other users and make comparative tests.A Computação em nuvem é um paradigma ainda com muitas áreas por explorar que vão desde a componente tecnológica à definição de novos modelos de negócio, mas que está a revolucionar a forma como projetamos, implementamos e gerimos toda a infraestrutura da tecnologia da informação. A Infraestrutura como Serviço representa a disponibilização da infraestrutura computacional, tipicamente um datacenter virtual, juntamente com um conjunto de APls que permitirá que aplicações, de forma automática, possam controlar os recursos que pretendem utilizar_ A escolha do fornecedor de serviços e a forma como este aplica o seu modelo de negócio poderão determinar um maior ou menor custo na operacionalização e manutenção das aplicações junto dos fornecedores. Neste sentido, esta dissertação propôs· se efetuar uma revisão bibliográfica sobre a temática da Computação em nuvem, a transmissão e o armazenamento seguro de conteúdos multimédia, utilizando a compressão sem perdas, em ambientes em nuvem públicos, e implementar um sistema deste tipo através da construção de uma aplicação que faz a gestão dos dados em ambientes de nuvem pública (dropbox e meocloud). Foi construída uma aplicação no decorrer desta dissertação que vai de encontro aos objectivos definidos. Este sistema fornece ao utilizador uma variada gama de funções de gestão de dados em ambientes de nuvem pública, para isso o utilizador tem apenas que realizar o login no sistema com as suas credenciais, após a realização de login, através do protocolo Oauth 1.0 (protocolo de autorização) é gerado um token de acesso, este token só é gerado com o consentimento do utilizador e permite que a aplicação tenha acesso aos dados / ficheiros do utilizador ~em que seja necessário utilizar as credenciais. Com este token a aplicação pode agora operar e disponibilizar todo o potencial das suas funções. Com esta aplicação é também disponibilizado ao utilizador funções de compressão e encriptação de modo a que possa usufruir ao máximo do seu sistema de armazenamento cloud com segurança. A função de compressão funciona utilizando o algoritmo de compressão LZMA sendo apenas necessário que o utilizador escolha os ficheiros a comprimir. Relativamente à cifragem utilizamos o algoritmo AES (Advanced Encryption Standard) que funciona com uma chave simétrica de 128bits definida pelo utilizador. Alicerçámos a investigação em duas partes distintas e complementares: a primeira parte é composta pela fundamentação teórica e a segunda parte consiste no desenvolvimento da aplicação informática em que os dados são geridos, comprimidos, armazenados, transmitidos em vários ambientes de computação em nuvem. A fundamentação teórica encontra-se organizada em dois capítulos, o capítulo 2 - "Background on Cloud Storage" e o capítulo 3 "Data Compression", Procurámos, através da fundamentação teórica, demonstrar a pertinência da investigação. transmitir algumas das teorias pertinentes e introduzir, sempre que possível, investigações existentes na área. A segunda parte do trabalho foi dedicada ao desenvolvimento da aplicação em ambiente "cloud". Evidenciámos o modo como gerámos a aplicação, apresentámos as funcionalidades, as vantagens. Por fim, refletimos sobre os resultados , de acordo com o enquadramento teórico efetuado na primeira parte e o desenvolvimento da plataforma. Pensamos que o trabalho obtido é positivo e que se enquadra nos objetivos que nos propusemos atingir. Este trabalho de investigação apresenta algumas limitações, consideramos que o tempo para a sua execução foi escasso e a implementação da plataforma poderia beneficiar com a implementação de outras funcionalidades. Em investigações futuras seria pertinente dar continuidade ao projeto ampliando as potencialidades da aplicação, testar o funcionamento com outros utilizadores e efetuar testes comparativos.Fundação para a Ciência e a Tecnologia (FCT

Hybrid Compressed Hash Based Homomorphic AB Encryption Algorithm for Security of data in the Cloud Environment

Cloud computing is an emerging technology in the world of computing. It provides a convenient virtual environment for on-demand access to different type of services and computing resources such as applications, networks and storage space in an efficient way. The virtual environment is a massive compound structure in terms of accessibility that made easy in a compact way and familiar of functional components. The complexity in virtual environment generates several issues related to data storage, data security, authorization and authentication in cloud computing. With the size of the data, it becomes difficult to the cloud user to store large amounts of information in the remote cloud servers due to high computational cost, insecurity and costs high per hour proportional to the volume of information. In this paper, we propose compressed hash based encrypted model for the virtual environment. The aim of this paper is to store huge amount of data in the cloud environment in the form of compressed and encrypted data in a secure way

Efficient simultaneous encryption and compression of digital videos in computationally constrained applications

This thesis is concerned with the secure video transmission over open and wireless network channels. This would facilitate adequate interaction in computationally constrained applications among trusted entities such as in disaster/conflict zones, secure airborne transmission of videos for intelligence/security or surveillance purposes, and secure video communication for law enforcing agencies in crime fighting or in proactive forensics. Video content is generally too large and vulnerable to eavesdropping when transmitted over open network channels so that compression and encryption become very essential for storage and/or transmission. In terms of security, wireless channels, are more vulnerable than other kinds of mediums to a variety of attacks and eavesdropping. Since wireless communication is the main mode in the above applications, protecting video transmissions from unauthorized access through such network channels is a must. The main and multi-faceted challenges that one faces in implementing such a task are related to competing, and to some extent conflicting, requirements of a number of standard control factors relating to the constrained bandwidth, reasonably high image quality at the receiving end, the execution time, and robustness against security attacks. Applying both compression and encryption techniques simultaneously is a very tough challenge due to the fact that we need to optimize the compression ratio, time complexity, security and the quality simultaneously. There are different available image/video compression schemes that provide reasonable compression while attempting to maintain image quality, such as JPEG, MPEG and JPEG2000. The main approach to video compression is based on detecting and removing spatial correlation within the video frames as well as temporal correlations across the video frames. Temporal correlations are expected to be more evident across sequences of frames captured within a short period of time (often a fraction of a second). Correlation can be measured in terms of similarity between blocks of pixels. Frequency domain transforms such as the Discrete Cosine Transform (DCT) and the Discrete Wavelet Transform (DWT) have both been used restructure the frequency content (coefficients) to become amenable for efficient detection. JPEG and MPEG use DCT while JPEG2000 uses DWT. Removing spatial/temporal correlation encodes only one block from each class of equivalent (i.e. similar) blocks and remembering the position of all other block within the equivalence class. JPEG2000 compressed images achieve higher image quality than JPEG for the same compression ratios, while DCT based coding suffer from noticeable distortion at high compression ratio but when applied to any block it is easy to isolate the significant coefficients from the non-significant ones. Efficient video encryption in computationally constrained applications is another challenge on its own. It has long been recognised that selective encryption is the only viable approach to deal with the overwhelming file size. Selection can be made in the spatial or frequency domain. Efficiency of simultaneous compression and encryption is a good reason for us to apply selective encryption in the frequency domain. In this thesis we develop a hybrid of DWT and DCT for improved image/video compression in terms of image quality, compression ratio, bandwidth, and efficiency. We shall also investigate other techniques that have similar properties to the DCT in terms of representation of significant wavelet coefficients. The statistical properties of wavelet transform high frequency sub-bands provide one such approach, and we also propose phase sensing as another alternative but very efficient scheme. Simultaneous compression and encryption, in our investigations, were aimed at finding the best way of applying these two tasks in parallel by selecting some wavelet sub-bands for encryptions and applying compression on the other sub-bands. Since most spatial/temporal correlation appear in the high frequency wavelet sub-bands and the LL sub-bands of wavelet transformed images approximate the original images then we select the LL-sub-band data for encryption and the non-LL high frequency sub-band coefficients for compression. We also follow the common practice of using stream ciphers to meet efficiency requirements of real-time transmission. For key stream generation we investigated a number of schemes and the ultimate choice will depend on robustness to attacks. The still image (i.e. RF’s) are compressed with a modified EZW wavelet scheme by applying the DCT on the blocks of the wavelet sub-bands, selecting appropriate thresholds for determining significance of coefficients, and encrypting the EZW thresholds only with a simple 10-bit LFSR cipher This scheme is reasonably efficient in terms of processing time, compression ratio, image quality, as well was security robustness against statistical and frequency attack. However, many areas for improvements were identified as necessary to achieve the objectives of the thesis. Through a process of refinement we developed and tested 3 different secure efficient video compression schemes, whereby at each step we improve the performance of the scheme in the previous step. Extensive experiments are conducted to test performance of the new scheme, at each refined stage, in terms of efficiency, compression ratio, image quality, and security robustness. Depending on the aspects of compression that needs improvement at each refinement step, we replaced the previous block coding scheme with a more appropriate one from among the 3 above mentioned schemes (i.e. DCT, Edge sensing and phase sensing) for the reference frames or the non-reference ones. In subsequent refinement steps we apply encryption to a slightly expanded LL-sub-band using successively more secure stream ciphers, but with different approaches to key stream generation. In the first refinement step, encryption utilized two LFSRs seeded with three secret keys to scramble the significant wavelet LL-coefficients multiple times. In the second approach, the encryption algorithm utilises LFSR to scramble the wavelet coefficients of the edges extracted from the low frequency sub-band. These edges are mapped from the high frequency sub-bands using different threshold. Finally, use a version of the A5 cipher combined with chaotic logistic map to encrypt the significant parameters of the LL sub-band. Our empirical results show that the refinement process achieves the ultimate objectives of the thesis, i.e. efficient secure video compression scheme that is scalable in terms of the frame size at about 100 fps and satisfying the following features; high compression, reasonable quality, and resistance to the statistical, frequency and the brute force attack with low computational processing. Although image quality fluctuates depending on video complexity, in the conclusion we recommend an adaptive implementation of our scheme. Although this thesis does not deal with transmission tasks but the efficiency achieved in terms of video encryption and compression time as well as in compression ratios will be sufficient for real-time secure transmission of video using commercially available mobile computing devices

Hybrid information security system via combination of compression, cryptography, and image steganography

Today, the world is experiencing a new paradigm characterized by dynamism and rapid change due to revolutions that have gone through information and digital communication technologies, this raised many security and capacity concerns about information security transmitted via the Internet network. Cryptography and steganography are two of the most extensively that are used to ensure information security. Those techniques alone are not suitable for high security of information, so in this paper, we proposed a new system was proposed of hiding information within the image to optimize security and capacity. This system provides a sequence of steps by compressing the secret image using discrete wavelet transform (DWT) algorithm, then using the advanced encryption standard (AES) algorithm for encryption compressed data. The least significant bit (LSB) technique has been applied to hide the encrypted data. The results show that the proposed system is able to optimize the stego-image quality (PSNR value of 47.8 dB) and structural similarity index (SSIM value of 0.92). In addition, the results of the experiment proved that the combination of techniques maintains stego-image quality by 68%, improves system performance by 44%, and increases the size of secret data compared to using each technique alone. This study may contribute to solving the problem of the security and capacity of information when sent over the internet

A Study on Visually Encrypted Images for Rights Protection and Authentication

首都大学東京, 2014-03-25, 博士(工学), 甲第444号首都大学東