306 resultados para Predicate Encryption
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Encryption of personal data is widely regarded as a privacy preserving technology which could potentially play a key role for the compliance of innovative IT technology within the European data protection law framework. Therefore, in this paper, we examine the new EU General Data Protection Regulation’s relevant provisions regarding encryption – such as those for anonymisation and pseudonymisation – and assess whether encryption can serve as an anonymisation technique, which can lead to the non-applicability of the GDPR. However, the provisions of the GDPR regarding the material scope of the Regulation still leave space for legal uncertainty when determining whether a data subject is identifiable or not. Therefore, we inter alia assess the Opinion of the Advocate General of the European Court of Justice (ECJ) regarding a preliminary ruling on the interpretation of the dispute concerning whether a dynamic IP address can be considered as personal data, which may put an end to the dispute whether an absolute or a relative approach has to be used for the assessment of the identifiability of data subjects. Furthermore, we outline the issue of whether the anonymisation process itself constitutes a further processing of personal data which needs to have a legal basis in the GDPR. Finally, we give an overview of relevant encryption techniques and examine their impact upon the GDPR’s material scope.
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Thesis (Master's)--University of Washington, 2016-08
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Transmitting sensitive data over non-secret channels has always required encryption technologies to ensure that the data arrives without exposure to eavesdroppers. The Internet has made it possible to transmit vast volumes of data more rapidly and cheaply and to a wider audience than ever before. At the same time, strong encryption makes it possible to send data securely, to digitally sign it, to prove it was sent or received, and to guarantee its integrity. The Internet and encryption make bulk transmission of data a commercially viable proposition. However, there are implementation challenges to solve before commercial bulk transmission becomes mainstream. Powerful have a performance cost, and may affect quality of service. Without encryption, intercepted data may be illicitly duplicated and re-sold, or its commercial value diminished because its secrecy is lost. Performance degradation and potential for commercial loss discourage the bulk transmission of data over the Internet in any commercial application. This paper outlines technical solutions to these problems. We develop new technologies and combine existing ones in new and powerful ways to minimise commercial loss without compromising performance or inflating overheads.
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Secure transmission of bulk data is of interest to many content providers. A commercially-viable distribution of content requires technology to prevent unauthorised access. Encryption tools are powerful, but have a performance cost. Without encryption, intercepted data may be illicitly duplicated and re-sold, or its commercial value diminished because its secrecy is lost. Two technical solutions make it possible to perform bulk transmissions while retaining security without too high a performance overhead. These are: 1. a) hierarchical encryption - the stronger the encryption, the harder it is to break but also the more computationally expensive it is. A hierarchical approach to key exchange means that simple and relatively weak encryption and keys are used to encrypt small chunks of data, for example 10 seconds of video. Each chunk has its own key. New keys for this bottom-level encryption are exchanged using a slightly stronger encryption, for example a whole-video key could govern the exchange of the 10-second chunk keys. At a higher level again, there could be daily or weekly keys, securing the exchange of whole-video keys, and at a yet higher level, a subscriber key could govern the exchange of weekly keys. At higher levels, the encryption becomes stronger but is used less frequently, so that the overall computational cost is minimal. The main observation is that the value of each encrypted item determines the strength of the key used to secure it. 2. b) non-symbolic fragmentation with signal diversity - communications are usually assumed to be sent over a single communications medium, and the data to have been encrypted and/or partitioned in whole-symbol packets. Network and path diversity break up a file or data stream into fragments which are then sent over many different channels, either in the same network or different networks. For example, a message could be transmitted partly over the phone network and partly via satellite. While TCP/IP does a similar thing in sending different packets over different paths, this is done for load-balancing purposes and is invisible to the end application. Network and path diversity deliberately introduce the same principle as a secure communications mechanism - an eavesdropper would need to intercept not just one transmission path but all paths used. Non-symbolic fragmentation of data is also introduced to further confuse any intercepted stream of data. This involves breaking up data into bit strings which are subsequently disordered prior to transmission. Even if all transmissions were intercepted, the cryptanalyst still needs to determine fragment boundaries and correctly order them. These two solutions depart from the usual idea of data encryption. Hierarchical encryption is an extension of the combined encryption of systems such as PGP but with the distinction that the strength of encryption at each level is determined by the "value" of the data being transmitted. Non- symbolic fragmentation suppresses or destroys bit patterns in the transmitted data in what is essentially a bit-level transposition cipher but with unpredictable irregularly-sized fragments. Both technologies have applications outside the commercial and can be used in conjunction with other forms of encryption, being functionally orthogonal.
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Homomorphic encryption is a particular type of encryption method that enables computing over encrypted data. This has a wide range of real world ramifications such as being able to blindly compute a search result sent to a remote server without revealing its content. In the first part of this thesis, we discuss how database search queries can be made secure using a homomorphic encryption scheme based on the ideas of Gahi et al. Gahi’s method is based on the integer-based fully homomorphic encryption scheme proposed by Dijk et al. We propose a new database search scheme called the Homomorphic Query Processing Scheme, which can be used with the ring-based fully homomorphic encryption scheme proposed by Braserski. In the second part of this thesis, we discuss the cybersecurity of the smart electric grid. Specifically, we use the Homomorphic Query Processing scheme to construct a keyword search technique in the smart grid. Our work is based on the Public Key Encryption with Keyword Search (PEKS) method introduced by Boneh et al. and a Multi-Key Homomorphic Encryption scheme proposed by L´opez-Alt et al. A summary of the results of this thesis (specifically the Homomorphic Query Processing Scheme) is published at the 14th Canadian Workshop on Information Theory (CWIT).
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This paper presents a novel algorithm to successfully achieve viable integrity and authenticity addition and verification of n-frame DICOM medical images using cryptographic mechanisms. The aim of this work is the enhancement of DICOM security measures, especially for multiframe images. Current approaches have limitations that should be properly addressed for improved security. The algorithm proposed in this work uses data encryption to provide integrity and authenticity, along with digital signature. Relevant header data and digital signature are used as inputs to cipher the image. Therefore, one can only retrieve the original data if and only if the images and the inputs are correct. The encryption process itself is a cascading scheme, where a frame is ciphered with data related to the previous frames, generating also additional data on image integrity and authenticity. Decryption is similar to encryption, featuring also the standard security verification of the image. The implementation was done in JAVA, and a performance evaluation was carried out comparing the speed of the algorithm with other existing approaches. The evaluation showed a good performance of the algorithm, which is an encouraging result to use it in a real environment.
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Qu-Prolog is an extension of Prolog which performs meta-level computations over object languages, such as predicate calculi and lambda-calculi, which have object-level variables, and quantifier or binding symbols creating local scopes for those variables. As in Prolog, the instantiable (meta-level) variables of Qu-Prolog range over object-level terms, and in addition other Qu-Prolog syntax denotes the various components of the object-level syntax, including object-level variables. Further, the meta-level operation of substitution into object-level terms is directly represented by appropriate Qu-Prolog syntax. Again as in Prolog, the driving mechanism in Qu-Prolog computation is a form of unification, but this is substantially more complex than for Prolog because of Qu-Prolog's greater generality, and especially because substitution operations are evaluated during unification. In this paper, the Qu-Prolog unification algorithm is specified, formalised and proved correct. Further, the analysis of the algorithm is carried out in a frame-work which straightforwardly allows the 'completeness' of the algorithm to be proved: though fully explicit answers to unification problems are not always provided, no information is lost in the unification process.
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This paper examines the so-called ’Unagi-sentence‘ in Japanese. So far, it has been taken for granted that the Unagi-sentence is incomplete syntactically and/or semantically. Because its structure apparently neither provides a fully-fledged semantic meaning, nor furnishes a plausible syntactic pattern (such as ‘subject-predicate‘), a number of previous works have considered the Unagi-sentence to be elliptic, and consequently reconstructed it as a complete sentence or established intermediate structures to account for its grammatical form. Other researchers have not used elliptic solutions, but sought to discover logical connections between the parts of the Unagi-sentence themselves. As a result, fixing their entire attention on the internal structure of the Unagi-sentence, these researchers inevitably needed to establish hypothetical constructs in order to explain the structure of the Unagi-sentence. The present author believes that the Unagi-sentence is neither incomplete nor a result of some hypothetical processes. The Unagi-sentence stands on its own as a complete utterance. It is basically an NP utterance which can be expanded to the form NP1 wa + NP2 da and its variations. The occurrence of the Unagi-sentence depends heavily on a presupposed context and its pragmatic features, without which the Unagi-sentence cannot exist. It is these features that the present article seeks to elucidate.
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In this paper we describe a distributed object oriented logic programming language in which an object is a collection of threads deductively accessing and updating a shared logic program. The key features of the language, such as static and dynamic object methods and multiple inheritance, are illustrated through a series of small examples. We show how we can implement object servers, allowing remote spawning of objects, which we can use as staging posts for mobile agents. We give as an example an information gathering mobile agent that can be queried about the information it has so far gathered whilst it is gathering new information. Finally we define a class of co-operative reasoning agents that can do resource bounded inference for full first order predicate logic, handling multiple queries and information updates concurrently. We believe that the combination of the concurrent OO and the LP programming paradigms produces a powerful tool for quickly implementing rational multi-agent applications on the internet.
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Program compilation can be formally defined as a sequence of equivalence-preserving transformations, or refinements, from high-level language programs to assembler code, Recent models also incorporate timing properties, but the resulting formalisms are intimidatingly complex. Here we take advantage of a new, simple model of real-time refinement, based on predicate transformer semantics, to present a straightforward compilation formalism that incorporates real-time constraints. (C) 2002 Elsevier Science B.V. All rights reserved.
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Although we have many electric devices at home, there are just few systems to evaluate, monitor and control them. Sometimes users go out and leave their electric devices turned on what can cause energy wasting and dangerous situations. Therefore most of the users may want to know the using states of their electrical appliances through their mobile devices in a pervasive way. In this paper, we propose an Intelligent Supervisory Control System to evaluate, monitor and control the use of electric devices in home, from outside. Because of the transferring data to evaluate, monitor and control user's location and state of home (ex. nobody at home) may be opened to attacks leading to dangerous situations. In our model we include a location privacy module and encryption module to provide security to user location and data. Intelligent Supervising Control System gives to the user the ability to manage electricity loads by means of a multi-agent system involving evaluation, monitoring, control and energy resource agents.
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It is difficult to get the decision about an opinion after many users get the meeting in same place. It used to spend too much time in order to find solve some problem because of the various opinions of each other. TAmI (Group Decision Making Toolkit) is the System to Group Decision in Ambient Intelligence [1]. This program was composed with IGATA [2], WebMeeting and the related Database system. But, because it is sent without any encryption in IP / Password, it can be opened to attacker. They can use the IP / Password to the bad purpose. As the result, although they make the wrong result, the joined member can’t know them. Therefore, in this paper, we studied the applying method of user’s authentication into TAmI.
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In this paper we examine the construction of first entities in narratives produced by children of 5, 7, 10 years and adults1 . The study demonstrates that when children reformulate they try to construct entities detached from the situation of enunciation, which means that they construct a detached or a translated plane and they construct linguistic existence of entities. Entities must first be introduced into the enunciative space and then comments will be made in subsequent utterances. Constructing existence supposes extraction. This consists of “singling out an occurrence, that is, isolating and drawing its spatiotemporal boundaries” (Culioli, 1990, p. 182) . Once the occurrence of the notion is constructed (which means it has become a separate occurrence with situational properties), children can predicate about it. However, there are children who do not construct the linguistic existence of entities. I hypothesize that the mode of task presentation influences the success of constructing linguistic existence. Sharing the investigator’s knowledge about the stimulus images, children do not ascribe an existential status to the occurrence of the notional domain.
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Mestrado em Engenharia Electrotécnica e de Computadores
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Maintaining a high level of data security with a low impact on system performance is more challenging in wireless multimedia applications. Protocols that are used for wireless local area network (WLAN) security are known to significantly degrade performance. In this paper, we propose an enhanced security system for a WLAN. Our new design aims to decrease the processing delay and increase both the speed and throughput of the system, thereby making it more efficient for multimedia applications. Our design is based on the idea of offloading computationally intensive encryption and authentication services to the end systems’ CPUs. The security operations are performed by the hosts’ central processor (which is usually a powerful processor) before delivering the data to a wireless card (which usually has a low-performance processor). By adopting this design, we show that both the delay and the jitter are significantly reduced. At the access point, we improve the performance of network processing hardware for real-time cryptographic processing by using a specialized processor implemented with field-programmable gate array technology. Furthermore, we use enhanced techniques to implement the Counter (CTR) Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) and the CTR protocol. Our experiments show that it requires timing in the range of 20–40 μs to perform data encryption and authentication on different end-host CPUs (e.g., Intel Core i5, i7, and AMD 6-Core) as compared with 10–50 ms when performed using the wireless card. Furthermore, when compared with the standard WiFi protected access II (WPA2), results show that our proposed security system improved the speed to up to 3.7 times.