250 research outputs found
Protection and Retrieval of Encrypted Multimedia Content: When Cryptography Meets Signal Processing
No full textThe processing and encryption of multimedia content are generally considered sequential and independent operations. In certain multimedia content processing scenarios, it is, however, desirable to carry out processing directly on encrypted signals. The field of secure signal processing poses significant challenges for both signal processing and cryptography research; only few ready-to-go fully integrated solutions are available. This study first concisely summarizes cryptographic primitives used in existing solutions to processing of encrypted signals, and discusses implications of the security requirements on these solutions. The study then continues to describe two domains in which secure signal processing has been taken up as a challenge, namely, analysis and retrieval of multimedia content, as well as multimedia content protection. In each domain, state-of-the-art algorithms are described. Finally, the study discusses the challenges and open issues in the field of secure signal processing.Electrical Engineering, Mathematics and Computer Scienc
LINGUPOETICS AND IMAGES IN FREE WORKS ERKIN A'ZAM
No full textErkin Azam is one of the artists who considers creativity as destiny. The author has won the hearts of readers mainly with his stories and short stories. But in recent years, the author's novel "Noise" was published. Several articles have been published about the work. The author's novel is based on symbolism and is one of the most unusual works. The novel seeks to portray a particular aspect of life in terms of its own style. Changes in the development of different genres can be seen in the genre of short stories in the works of the writer. Umarali Normatov, a literary critic who has written about short stories in recent years, writes: “When we look at our short stories today, first of all, the subject matter attracts attention in terms of problems, form, style; Among them are works on historical, modern, socio-political, family, romantic themes, both traditional romantic, realistic, modernist, serious and humorous, adventure-detective. no matter what the diversity. ” As noted, in this genre, a variety of thematic stories have been created, in which the human psyche, character traits are interpreted. Analysis of the artistic features of the author's novel "Noise", the demonstration of the writer's skill determines the relevance of the topi
The Linguopoetic Nature of the Artistic Repetition in the Works of Erkin Azam
No full textIn the last years of study of Uzbek linguistics, the attention to analyzing a text and its components is obviously seen in the fields of increasing of text linguistics, pragmalinguistics, and lingua poetics. As such a new field, on study of Uzbek linguistics, the following matters are actual tasks, such as semiotics in the circle of linguistics, pragmatics, and connotation, as well, producing theoretical principles of lingua poetics embodied the following concepts affiliated with the literature, for instance, images, individuality, thought, literary idea, definitely speaking, to put it in one system, to study and systematize its research methodology, style and means, hierarchical development in the complete plan. On the basis of it, in the works of certain authors, studying the factors of the private actuality of common lingua poetic bases on the basis of commonality principles of author-language-artistic merit are considered central issues of anthropocentric approach. The peculiarity of the actuality of language lingual opportunity in the works of a certain writer has been studied by the researchers on different aspects on the basis of various methodological bases. On the study of Uzbek linguistics, it might be divided into three groups, such as lexical-grammatical peculiarity of the working language and as the lingua stylistic and lingua poetic studies. Writer Erkin Azamov's prose has been studied from the point of literary studies in some grades, but it hasn't been researched as a source of lingua poetic research. Erkin Azam successfully uses all the types of artistic repetitions as the repetitions in the parts of speech, according to the distance - contact and distant repetitions, according to the manner of expressions phonetic, morphological, lexical and syntactic repetitions, making the language of his works figurative, unique, impressive; and meeting the requirements of the artistic merits. The artistic repetitions in terms of phonetics, morphology, lexicology, and syntax serve to increase an artistic value of E.Azam‟s works. The main task of them is to reinforce a flurry of speculations and the meaning of the astonishment, order, denial, to provide with musicality and clarity of images. The repetition as an expressive-syntactic means turns into the individual style of the author and is used as a linguopoetic means for increasing the artistic features of the works.Keywords and expressions: linguopoetics, expressive, syntax, expressive-emotional, figurativeness, contact repetitions, distant repetitions, phonetic repetitions, lexical repetitions, morphological repetitions, syntactic repetitions
The Linguopoetic Nature of the Artistic Repetition in the Works of Erkin Azam
No full textIn the last years of study of Uzbek linguistics, the attention to analyzing a text and its components is obviously seen in the fields of increasing of text linguistics, pragmalinguistics, and lingua poetics. As such a new field, on study of Uzbek linguistics, the following matters are actual tasks, such as semiotics in the circle of linguistics, pragmatics, and connotation, as well, producing theoretical principles of lingua poetics embodied the following concepts affiliated with the literature, for instance, images, individuality, thought, literary idea, definitely speaking, to put it in one system, to study and systematize its research methodology, style and means, hierarchical development in the complete plan. On the basis of it, in the works of certain authors, studying the factors of the private actuality of common lingua poetic bases on the basis of commonality principles of author-language-artistic merit are considered central issues of anthropocentric approach. The peculiarity of the actuality of language lingual opportunity in the works of a certain writer has been studied by the researchers on different aspects on the basis of various methodological bases. On the study of Uzbek linguistics, it might be divided into three groups, such as lexical-grammatical peculiarity of the working language and as the lingua stylistic and lingua poetic studies. Writer Erkin Azamov's prose has been studied from the point of literary studies in some grades, but it hasn't been researched as a source of lingua poetic research. Erkin Azam successfully uses all the types of artistic repetitions as the repetitions in the parts of speech, according to the distance - contact and distant repetitions, according to the manner of expressions phonetic, morphological, lexical and syntactic repetitions, making the language of his works figurative, unique, impressive; and meeting the requirements of the artistic merits. The artistic repetitions in terms of phonetics, morphology, lexicology, and syntax serve to increase an artistic value of E.Azam‟s works. The main task of them is to reinforce a flurry of speculations and the meaning of the astonishment, order, denial, to provide with musicality and clarity of images. The repetition as an expressive-syntactic means turns into the individual style of the author and is used as a linguopoetic means for increasing the artistic features of the works.Keywords and expressions: linguopoetics, expressive, syntax, expressive-emotional, figurativeness, contact repetitions, distant repetitions, phonetic repetitions, lexical repetitions, morphological repetitions, syntactic repetitions
Charon: The Pluggable Filtering Framework for the Fox-IT DataDiode
No full textConfidentiality This report contains detailed information about the design and implementation of Charon. The DataDiode, and by extension Charon, is used in many high security environments. They handle highly confidential data, and are used by clients ranging from major companies to governmental organizations. Because of this, the details about Charon disclosed in this report can not be made publicly available online. A physical copy of the full version of the report is kept by the Computer Science Bachelor Project Coordinator of the TU Delft. To access the full report, please contact the current coordinator. The Dutch IT security company Fox-IT created the DataDiode, a product that connects two networks with different security levels providing a one-way data path. A new appliance of the DataDiode is currently under development. As part of our BSc project, we were given de assignment to develop Charon, a pluggable filtering framework for the new DataDiode appliance. This thesis describes the complete process of the project and elaborates the choices we have made. In the introduction we explain what a Computer Science Bsc project is at Delft University of Technology and describe Fox-IT and the DataDiode. After this we give a detailed description of the assignment, define the requirements, explain the design methodology and why we consider Charon to be a suitable name for the project. In the next chapter we elaborate on the design choices we have made and illustrate these choices with UML-diagrams. The chapter that follows is about the implementation of the system; we describe the libraries, tools and system components. After this chapter we evaluate the implementation by comparing the implemented functionality with the requirements. We also explain in which way we tested our system to make sure it runs according to the specifications, about the Fox-IT challenge and the code evaluation. We reflect the process in the succeeding chapter where we compare the initial planning with the actual execution, and explain the collaboration between the group members. In the last chapter, we conclude the thesis and list several recommendations for Fox-IT. The appendices that are attached to this thesis contain a complete class diagram, several documents that are created during the orientation phase and a user manual.Computer ScienceElectrical Engineering, Mathematics and Computer Scienc
DICOMmunicator: An Online Medical Image Transfer Service
No full textMedical doctors and researchers have to send medical image files to each other. This may be for a consult, because a patient is treated by a different doctor or because the files are to be used for research. The files contain personal health information, and privacy rules have to be satisfied before the files may be sent. To securely send the files the data should be encrypted and anonymized. The problem led to the development of DICOMmunicator, a single page web application. It allows clinicians to use the self-descriptive application to send DICOM files to another doctor. DICOMmunicator removes patient information from the files that are uploaded, encrypts the files and stores them in a database. The recipient of the files is sent an email containing the key used for decryption allowing only that person to download the files.Technische InformaticaComputer ScienceElectrical Engineering, Mathematics and Computer Scienc
Trait-based heterogeneous populations plus (TbHP+) genetic algorithm
No full textThis study developed a variant of genetic algorithm (GA) model called the trait-based heterogeneous populations plus (TbHP+). The developed TbHP+ model employs a memory concept in the form of immunity and instinct to provide the populations with a more efficient guidance. Also, it has an ability to vary the number of individuals during the search process, thus allowing an automatic determination of the size of the population based on the individual qualities such as character fitness and credit for immunity. The algorithm was tested against the classical GA model in convergence and minimum error performance. For this purpose, 5 different mathematical functions from the literature were employed. The selected functions have different topological characteristics, ranging from simple convex curves with 2 variables to complex trigonometric ones having several hilly shapes with more than 2 variables. The developed model and the classical GA model were applied to finding the global minima of the functions. The comparison of the results revealed that the developed TbHP+ model outperformed the classical GA in faster convergence and minimum errors, which may be explained by the adaptive nature of the new paradigm
Incorporating Leveled Homomorphic Encryption-based Private Information Retrieval in Federated eID Schemes to Enhance User Privacy
No full textNumerous services are being offered over the Internet and require identification of users as in face-to-face interactions. To simplify the authentication procedure and reduce the need to manage multiple credentials to access services, Electronic Identification (eID) schemes have been introduced. eID schemes commonly involve many service providers (SPs) which provide services, such as online shopping, social networks, etc. to users and identity providers (IDPs) which verify the identity of users and facilitate the users to authenticate him/herself to SPs. In federated eID schemes, IDPs store identifiable user information (attributes), often with a unique ID, and attest on these attributes to SPs. In this work we address the privacy concerns of storing user attributes at the IDP which allows the IDP to profile the behaviour and activities of users. We propose to store the attributes in a privacy friendly manner so that they cannot be directly linked to a particular user even if the data is leaked. Then we include an additional step incorporating private information retrieval (PIR) in the usual authentication flow of federated eID scheme so that the IDP can perform its role of authenticating and managing the user’s identity without turning into a privacy hotspot. The privacy enhancement offered by our work needs to be accompanied by privacy-friendly authentication, which does not reveal the identity of the user, to be effective. Finally, through a proof-of-concept implementation we show a practical variant of our scheme in which the IDP, with millions of users, partitions its database.Electrical Engineering, Mathematics and Computer ScienceIntelligent System
Efficient protocols for joint random number generation using multi-party computation techniques: Efficiente protocollen voor het genereren van samenhangende random getallen voor groepsberekeningen
No full textThere exists several applications where it is desirable to produce random numbers such that adding these random numbers yields a publicly known sum. Efficient algorithms are necessary for generating such joint random numbers in an untrusted environment in settings such as, but not restricted to, multi-party computation (MPC). Applications range all the way to secure license plate identification or facial recognition. In this thesis, we give a brief introduction into the field of cryptography. Then, we focus on a core component in MPC protocols, namely on how to generate these joint random numbers. We first analyze the existing work. Then, we propose two new protocols to efficiently achieve joint random number generation, both in terms of computational demand and communication. We show that our second protocol can also omit the need for secure networks, meaning all the messages can be public. In addition to these protocols we also introduce an extension for general joint random number generation protocols in large networks based on a star topology, with explicit protocols for parties that are joining or leaving. We analyze all our proposals in terms of security, complexity and performance. Finally, we discuss questions that remain open after this thesis.Electrical Engineering, Mathematics and Computer ScienceApplied MathematicsOptimizatio
Secure signal processing: Privacy preserving cryptographic protocols for multimedia
No full textRecent advances in technology provided a suitable environment for the people in which they can benefit from online services in their daily lives. Despite several advantages, online services also constitute serious privacy risks for their users as the main input to algorithms are privacy sensitive such as demographic information, shopping patterns, medical records, etc. While traditional security mechanisms can eliminate a number of attacks from outside, these mechanisms can not protect the privacy of the users as the service provider itself constitutes the biggest potential risk. In this thesis, we focus on principled solutions to protect the privacy of users in multimedia applications. For this purpose we propose to keep the privacy-sensitive data safe by means of encryption during processing. This approach eliminates the risk of possible privacy abuse as the sensitive data is only available to the owner but no other party. However, once encrypted, the structure in data is destroyed as a consequence of the encryption procedure and thus we need appropriate tools to process encrypted data. Therefore, we focus on a number of cryptographic tools such as homomorphic encryption schemes and multiparty computation (MPC) techniques to realize privacy-preserving multimedia applications. The proposed principled solutions consider the signal processing aspect of the multimedia applications which is a new idea to the best of our knowledge. In particular, we focus on a number of prototypical applications namely, face detection, user clustering in a social network, recommendation generation and anonymous fingerprinting. Based on these selected applications, we addressed the major challenges for secure signal processing: data representation, data expansion, realizing linear and non-linear operations and efficiency of the proposed protocols in terms of communication and computational costs. We propose to scale and round the signal values prior to encryption as these operations are highly inefficient to be realized in the encrypted domain. Moreover, we reserve sufficient space in terms of bit length for each signal sample to accommodate the possible expansion in bit size in the subsequent processing steps. However, reserving more bits for signals does not contradict with the data expansion problem. As the cipher text space is much larger than the size of the original -- and even scaled -- signal samples, data expansion after encryption increases data transmission and storage costs significantly. In order to minimize the cost we propose to pack a number of signal samples in one encryption and process them when they are in the packed form. This approach requires cryptographic protocols particularly designed for the packed data but in the end saves considerable resources regarding bandwidth and storage capacity, even computational power. Homomorphism plays a crucial role in our proposed solutions. With the help of homomorphic encryption, we are able to implement linear operations such as correlation and projection without interaction. However, linear operations are only a part of the signal processing. For the non-linear operations like distance computation, thresholding and comparison, we exploit MPC techniques. These techniques are often interactive and computationally expensive compared to the original systems in plain. However, by using data packing and designing the protocols with care, the communication and computational costs were reduced significantly. In this thesis, we have shown that preserving privacy for multimedia signal processing is feasible. We determined the major challenges of secure signal processing and combined a set of cryptographic tools successfully with signal processing to realize the applications in the encrypted domain. The proposed solutions demonstrate that the privacy concerns in multimedia signal processing applications can be coped with by using cryptographic tools. Moreover, protocols that are designed to realize certain operations in the encrypted domain can be used in other applications and settings with a number of modifications.MediamaticsElectrical Engineering, Mathematics and Computer Scienc
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