The purpose of the investigation is to determine the most effective solution, which allows safe storing and transmitting of financial information in terms of execution speed, resistance to hacking and ease of implementation. Research object is subject area related to the transfer of encrypted financial information like: encryption algorithms, algorithm of hashing functions, algorithm of electronic digital signature. The result of research is the software implementation of the server and client for sending encrypted information. Also client could only encrypt/decrypt information. The main part of research is to find the most suitable algorithm for transfer of encrypted banking information. The solution has been implemented on the Java programming language in programming environment IntelliJ IDEA 8, using Java Cryptography Extension (JCE) for digital signature.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The arms control verification activity is executed between countries, so various telemetry data will be remote-transmitted in the public signal channel and can be easily tampered. In order to secure this data’s authenticity and integrality, the paper has established a Multi-layer Data Authentication Protocol (MDAP) in which the key cryptographic technologies are digital signature and authentication. Meanwhile, overall evaluations of MDAP have been presented. We proved the MDAP is secure.

In this work, we study the cryptographic primitive: signcryption, which combines the functionalities of digital signatures and public-key encryption. We first propose two generic transforms from meta-ElGamal signature schemes to signcryption schemes. These constructions can be thought of as generalisations of the signcryption schemes by Zheng and Gamage et al. Our results show that a large class of signcryption schemes are outsider IND-CCA2 secure and insider UF-CMA secure. As a by-product, we also show that the meta-ElGamal signature schemes, for which no previous formal security proofs have been shown, are UF-CMA secure. We then propose a modification of one of the transforms in order to achieve insider IND-CCA2 security in addition to insider UF-CMA security. This modification costs just one extra exponential operation. In particular, we can apply this modification to the Zheng signcryption scheme to make it fully insider secure. Finally, we propose a generic transform from a two-key signcryption scheme to a one-key signcryption scheme while preserving both confidentiality and unforgeability. Our result shows that if we have an insider IND-CCA2 and UFCMA secure two-key signcryption scheme, then it can be turned into an insider IND-CCA2 and UF-CMA secure one-key signcryption scheme. We also show that an insider IND-CCA2 and UF-CMA secure one-key signcryption scheme induces a secure combined public-key scheme; that is, a combination of a signature scheme and a public-key encryption scheme that can securely share the same key pair. Combining previous results suggests that we can obtain a large class of insider secure one-key signcryption schemes from meta-ElGamal signature schemes, and that each of them can induce a secure combined public-key scheme.

This thesis looks at the function of signatures in visual art using the theory of Jacques Derrida and a series of paradigmatic historical examples. Specifically, it departs from ‘Signature Event Context’ (SEC) to establish signature outside the idiom of visual art as a social process. Having established signature as process designed to guarantee presence, it suggests that signature should be considered a method of production. As a method of production, signature has a significant contemporary relevance for dematerialised and Relational Art practices which are frequently held to be ‘unsigned’. This thesis suggests grounds for questioning the unsigned quality of Relational Art, and looks at what signatory production means for it. Until the 1990s, signature was mostly ignored as a subject for serious art historical scholarship. It is still rarely indexed as a subject even when it warrants a mention in the body of a text. Although a clutch of recent studies have addressed its occurrence in the work of individual artists, or within the boundaries of narrowly defined eras, there is little work - if any - which attempts to connect these pockets of knowledge with a conceptual grounding of what signature does in order to develop a connected narrative and broad understanding for its place. As a result, there is little interrogation of signature’s mechanism alongside historical examples, and scholarship is instead focused on its appearance. This thesis attempts a broad, conceptually informed, historical survey, using examples that date as far back as the sixth century BC. The aim is to unpack the signature-form ‘R. Mutt’ which appears on Marcel Duchamp’s Readymade, Fountain (1917), a work with great conceptual importance for contemporary dematerialised and Relational Art practices. In bringing SEC into close 3 proximity to Fountain, the thesis establishes potential grounds for reading a significant theoretical relationship between Derrida and Duchamp, a pairing which has been neglected by scholars despite conceptual sympathies between them.

<p>Voice over Internet Protocol (VoIP), also called IP telephony is rapidly becoming a familiar term and as a technology it is invading the enterprise, private usage, and educational and government organizations. Exploiting advanced voice coding & compression techniques and bandwidth sharing over packet switched networks, VoIP can dramatically improve bandwidth efficiency. Moreover enhanced security features, mobility support, and cost reduction features of VoIP are making it a popular choice for personal communication. Due to its rapid growth in popularity VoIP is rapidly becoming the next generation phone system.</p><p>Lawful interception is a mean of monitoring private communication of users that are suspected of criminal activities or to be a threat to national security. However, government regulatory bodies and law enforcement agencies are becoming conscious of the difficulty of lawful interception of public communication due to the mobilitysupport and advanced security features implemented in some implementations of VoIP technology. There has been continuous pressure from the government upon the operators and vendors to find a solution that would make lawful interception feasible and successful. Key escrow was proposed as a solution by the U. S. National Security Agency. In key escrow the key(s) for a session are entrusted to a trusted third party and upon proper authorization law enforcement agencies can receive the session key(s) from this trusted third party However, key escrow adds some security vulnerabilities and potential risks as an unethical employee of the key escrow agent (or a law enforcement agency that has received the session key(s)) can misuse the key(s) to forge content of a communication session -- as he or she possesses the same key(s) as the user used for this session.</p><p>This thesis addresses the issue of forged session content, by proposing, implementing, and evaluating a cryptographic model which allows key escrow session content. The implementation utilizes an existing implementation of a Session Initiation Protocol (SIP) user agent ‘minisip’ developed at KTH. The performance evaluation results suggest that the proposed model can support key escrow while protecting the user communication from being forged with the cost of minimal computational resource and negligible overhead. <em>without</em> the possibility of undetectable fabrication of<em><strong>  </strong></em>session content. The implementation utilizes an existing implementation of a Session Initiation Protocol (SIP) user agent ‘minisip’ developed at KTH. The performance evaluation results suggest that the proposed model can support key escrow while protecting the user communication from being forged with the cost of minimal computational resource and negligible overhead.</p>

L'analyse de la fonction cérébrale à de multiples échelles est une étape nécessaire pour comprendre ses complexités. Dans ce travail de thèse, nous avons étudié cet aspect aux niveaux microscopiques et macroscopiques en utilisant des enregistrements invasifs et non-invasifs. Nous avons utilisé une série d'outils d'analyse communicationnels et de corrélation pour étudier l'activité cérébrale pendant l'éveil et le sommeil. Dans une première étude, nous avons analyse les enregistrements simultanés d'electroencephalogramme (EEG) etmagnetoencephalogramme (MEG) dans le cerveau de sujets éveillés. Nous montrons théoriquement, que si le milieu est résistif, le comportement d'échelle en fréquence doit être le même pour les signaux EEG and MEG à basse fréquence (˂10 Hz). Afin de tester cette prédiction, nous avons analyse le spectre d'enregistrements EEG et MEG simultanés de quatre sujets humains. Le comportement d'échelle en fréquence de l'EEG montre des variations cohérentes sur la surface du cerveau, avec des exposants en général compris entre 1/ f et 1/ f 2; ces exposants tendent à être plus faibles dans les régions temporales et pariétales. Dans une région donnée, les exposants de la MEG ont une variabilité plus grande que pour l'EEG, mais les deux signaux ont systématiquement un exposant différent. Dans certains cas, les exposants sont proches, mais ces cas correspondent 'a un mauvais rapport signal/bruit pour la MEG. Plusieurs méthodes de corrections du bruit instrumental et environnemental ont été testées, et dans tous les cas, ces méthodes augmentent la différence de comportement spectral entre l'EEG et la MEG. En conclusion, il y a une différence significative de comportement d'échelle en fréquence entre EEG et MEG, ce qui peut être explique si le milieu extracellulaire (incluant d'autres couches telles que la dure-mère et le crane) est globalement non-résistif. La nature résistive ou non-résistive du milieu extracellulaire est un déterminant important pour la modélisation des potentiels extracellulaires. Au cours d'une seconde étude, nous avons analyse la dynamique spatio-temporelle de l'excitation et de l'inhibition pendant le sommeil 'a partir d'enregistrements intra-crâniens à haute densité. Ces enregistrements à haute densité permettent la séparation efficace entre cellules "regular spiking" (RS) et "fast spiking" (FS). La haute densité des électrodes permet d'obtenir des connections apparemment mono-synaptiques, et de corroborer cette séparation RS-FS avec la nature excitatrice ou inhibitrice de la connexion. Cette procédure confirme que les cellules classifiées comme FS sont toujours inhibitrices, alors que les RS sont toujours excitatrices, et donc peuvent être classifiées respectivement comme cellules pyramidales ou interneurones inhibiteurs. Finalement, nous investiguons la dynamique des corrélations au sein de chaque classe de neurone. Les corrélations entre excitateurs montrent une décroissance exponentielle avec la distance, tandis que les cellules inhibitrices restent corrélées 'a plus grande distance. L'amplitude des corrélations dépend de l'échelle temporelle du calcul de corrélation, mais pas la constante spatiale. Cette constante est compatible avec la taille typique des colonnes corticales chez l'homme. Ces résultats permettent, pour la première fois, de caractériser l'activité neuronale et l'interaction entre excitation et inhibition dans le néocortex humain. Dans une troisième étude, nous avons investigue les signatures de la dynamique complexe et l'activité auto-organisée, à partir d'enregistrements intra-crâniens chez le chat, le singe et l'homme. Nous utilisons des enregistrements à haute densité dans le cortex moteur du chat (96 électrodes), le cortex moteur et prémoteur du singe et dans le cortex temporal humain (96 électrodes) de patients épileptiques. Lors d'avalanches définies à partir d'unités (jusqu''a 160 neurones), les distributions ne se comportent pas en loi de puissance, mais tendent à être exponentielles ou intermédiaires. Nous analysons également les potentiels de champ (LFPs), et en particulier les pics négatifs (nLFPs) au sein de l'ensemble d'électrodes (de 96 a 128 sites, selon la configuration d'enregistrement). Dans ce cas, les avalanches définies à partir des nLFPs peuvent se comporter en loi d'échelle, comme observé précédemment chez le singe. Cependant, les avalanches définies à partir des pics positifs (pLFPs), qui ne sont pas directement reliées aux décharges des neurones, ont le même comportement. Une analyse plus détaillée en utilisant la représentation cumulée (CDF) ne confirme pas la présence de loi de puissance. Les mêmes résultats s'appliquent au chat, au singe et aux enregistrements humains, pendant différents états cérébraux d'éveil et de sommeil. Nous avons également testé des distributions alternatives, et des processus multi-exponentiels semblent expliquer les distributions obtenues, de fac¸on optimale pour des distributions bi-exponentielles. L'ensemble de ces résultats ne montrent pas d'évidence de loi de puissance ou d'états critiques dans le cerveau éveillé ou en sommeil de différents mammifères, du chat 'a l'homme. Finalement, dans un appendice, nous montrons des résultats préliminaires concernant les relations entre cellules excitatrices et inhibitrices, et les potentiels de champ locaux pendant le sommeil humain. Nous avons pu séparer les cellules entre "regular-spiking" (RS) et "fastspiking" (FS), ce qui a été confirmé par connections monosynaptiques (voir Peyrache et al., PNAS, 2012). Nous analysons ici la décharge spécifique des cellules RS et FS pendant différents états d'éveil et de sommeil, sélectionnés sans activité interictale. Jusqu''a 92 unités enregistrées simultanément, procurent une base solide pour la caractérisation de la dynamique de l'excitation et de l'inhibition pendant ces différents états. Pendant le sommeil lent (Stade III ou IV), domine par les ondes lentes de type delta, tous les neurones déchargent selon des états "Up" ou "Down", en relation avec les ondes lentes du LFP, comme décrit précédemment. Les cellules RS et FS sont toutes silencieuses pendant les états "Down". Pendant le sommeil REM et pendant l'éveil, les neurones déchargent de fac¸on irrégulière alors que le LFP ou l'ECoG sont désynchronisées. Dans tous les états les cellules FS déchargent plus que les cellules RS (4 ou 5 fois plus en moyenne). En conclusion, ces résultats procurent une caractérisation des différents rôles de l'excitation et de l'inhibition pendant l'éveil et le sommeil chez l'homme. En conclusion, nous avons utilisé différentes méthodes de mesure, aux échelles microscopiques (activité unitaire), mésoscopique (LFP) etmacroscopiques (ECoG, EEG,MEG), pour caractériser les états de veille et sommeil chez l'homme (ainsi que chez le chat et le singe dans une étude). Nous concluons que le cerveau suit une dynamique complexe à toutes les échelles. Il n'y a pas d'évidence de dynamique auto-organisée critique, mais l'activité du cerveau manifeste d'autres signes d'auto-organisation, comme l'activité synchrone à grande distance et des processus multi-exponentiels. Nous suggérons que ces résultats peuvent être expliques par l'interaction entre excitation et inhibition. Nous anticipons que des réseaux d'oscillateurs couples, avec interaction entre excitation et inhibition, devraient pouvoir expliquer ces résultats. Cette perspective constitue un défi pour des études futures.

Pulmonary hypertension (PH), when it complicates sarcoidosis, carries a poor prognosis, in part because it is difficult to detect early in patients with worsening respiratory symptoms. Pathogenesis of sarcoidosis occurs via incompletely characterized mechanisms that are distinct from the mechanisms of pulmonary vascular remodeling well known to occur in conjunction with other chronic lung diseases. To address the need for a biomarker to aid in early detection as well as the gap in knowledge regarding the mechanisms of PH in sarcoidosis, we used genome-wide peripheral blood gene expression analysis and identified an 18-gene signature capable of distinguishing sarcoidosis patients with PH (n = 8), sarcoidosis patients without PH (n = 17), and healthy controls (n = 45). The discriminative accuracy of this 18-gene signature was 100% in separating sarcoidosis patients with PH from those without it. If validated in a large replicate cohort, this signature could potentially be used as a diagnostic molecular biomarker for sarcoidosis-associated PH.

There are around 10,426 bird species around the world. Recognizing the bird species for an untrained person is almost impossible either by watching or listening them. In order to identify the bird species from their sounds, there is a need for an application that can detect the bird species from its sound. Time-frequency domain analysis techniques are used to implement the application. We implemented two time-frequency domain feature extraction methods. In feature extraction, a signature matrix which consist of extracted features is created for bird sound signals. A database of signature matrix is created with bird chirps extracted features. We implemented two feature classification methods. They are auto-correlation feature classification method and reference difference feature classification method. An unknown bird chirp is compared with the database to detect the species name. The main aim of the research is to implement the time-frequency domain feature extraction method, create a signature matrix database, implement two feature classification methods and compare them. At last, bird species were identified in the research and the auto-correlation classification method detects the bird species better than the reference difference classification method.

This thesis consists of two parts. The first part (Chapters 2-4) focuses on the problem of inverting the signature of a path of bounded variation, and we present three results here. First, we give an explicit inversion formula for any axis path in terms of its signature. Second, we show that for relatively smooth paths, the derivative at the end point can be approximated arbitrarily closely by its signature sequence, and we provide explicit error estimates. As an application, we give an effective inversion procedure for piecewise linear paths. Finally, we prove a uniform estimate for the signatures of paths of bounded variations, and obtain a reconstruction theorem via that uniform estimate. Although this general reconstruction theorem is not computationally efficient, the techniques involved in deriving the uniform estimate are useful in other situations, and we also give an application in the case of expected signatures for Brownian motion. The second part (Chapter 5) deals with rough paths. After introducing proper backgrounds, we extend the uniform estimate above to the context of rough paths, and show how it can lead to simple proofs of distance bounds for Gaussian iterated integrals.

Identifying the natal origin of fish is important to understand connectivity among populations. Capelin, Mallotus villosus, is a key forage fish species that spawns at beach and deep-water habitats along the Newfoundland coast. I investigated the ability to identify the natal habitat of larval capelin using otolith chemical signatures quantified via LA ICP-MS. Otolith signatures of larvae reared under identical conditions were highly variable and classification into treatments was low (~50%). To investigate whether maternal investment was responsible for this variability, artificially fertilized eggs were reared under controlled treatments. Otolith signatures reliably classified individuals into families with high success (83.4%), suggesting maternal investment may confound our ability to identify natal origin. Eggs incubated in water enriched with 137Ba revealed trace elements from the environment are being incorporated into developing otoliths. These findings suggest moderate-high differences in water chemistry and environmental conditions are required to identify the natal origin of capelin. / October 2016