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A well known birthday paradox is one the most important problems in cryptographic applications. Incremental hash functions or digital signatures in public key cryptography and low-weight parity check equations of LFSRs in stream ciphers are examples of such applications which benet from birthday problem theories to run their attacks. Wagner introduced and formulated the k-dimensional birthday problem and proposed an algorithm to solve the problem in O(k.m^ 1/log k ). The generalized birthday solutions used in some applications to break Knapsack based systems or collision nding in hash functions. The optimized birthday algorithms can solve Knapsack problems of dimension n which is believed to be NP-hard. Its equivalent problem is Subset Sum Problem nds the solution over Z/mZ. The main property for the classication of the problem is density. When density is small enough the problem reduces to shortest lattice vector problem and has a solution in polynomial time. Assigning a variable to each element of the lists, decoding them into a matrix and considering each row of the matrix as an equation lead us to have a multivariate polynomial system of equations and all solution of this type can be a solution for the k- list problem such as F4, F5, another strategy called eXtended Linearization (XL) and sl. We discuss the new approaches and methods proposed to reduce the complexity of the algorithms. For particular cases in over-determined systems, more equations than variables, regarding to have a single solutions Wolf and Thomea work to make a gradual decrease in the complexity of F5. Moreover, his group try to solve the problem by monomials of special degrees and linear equations for small lists. We observe and compare all suggested methods in this

A new cryptanalytic application is proposed for a number theoretic tool Weil sum to the birthday attack against multivariate quadratic trapdoor function. This new customization of the birthday attack is developed by evaluating the explicit Weil sum of the underlying univariate polynomial and the exact number of solutions of the associated bivariate equation. I designed and implemented new algorithms for computing Weil sum values so that I could explicitly identify some class of weak Dembowski- Ostrom polynomials and the equivalent forms in the multivariate quadratic trapdoor function. This customized attack, also regarded as an equation solving algorithm for the system of some special quadratic equations over finite fields, is fundamentally different from the Grobner basis methods. The theoretical observations and experiments show that the required computational complexity of the attack on these weak polynomial instances can be asymptotically less than the square root complexity of the common birthday attack by a factor as large as 2^(n/8) in terms of the extension degree n of F2n. I also suggest a few open problems that any MQ-based short signature scheme must explicitly take into account for the basic design principles.

The particular characteristics of Pinter’s theatre such as the theme of violence, the competitive interpersonal relationships, the implied unwillingness in communication between the characters and the distinctive use of silences and pauses, distinguish his work from the writers of the absurd. Pinter makes particular use of “Silences” and “Pauses” as theatrical techniques that present a non-verbal way of communication in his plays. The frequent use of these particular techniques in Pinter’s dialogue has urged some critics to coin new expressions such as “Pinteresque” or “Pinter Pause” in the vocabulary of drama to specify Pinter’s technique. One of the important objectives in this essay is to point out the fundamental significance and function of the “Silences” and “Pauses” in Pinter’s work and point out their distinction. I will discuss how the silences and pauses function in Pinter’s theatre as a non-verbal way of communication by creating fragments in the dialogue.   The plays which will be analyzed in this essay are: The Room, The Dumb Waiter, The Birthday Party and The Caretaker. My objective in this essay is to explore the context of these plays with regards to the theme of menace. In the first chapter, I mainly aim to explore the menacing context of these plays regarding the structure of menace and the ways it takes place in each play separately. This analysis will be presented in relation to the spatial territory in which the characters are confined. My aim is also to describe why menace is presented in a theatrical sense. I have chosen to quote some significant passages of each play in each section to illustrate my purposes in the first chapter. The aim of the second chapter is to define the character types involved in the presentation of menace, “The Intruders” and “The Victims”, and to analyze the strategies their use in encounters with each other. After describing the character types I will explore in detail how “The Intruders” use linguistic strategies to confuse and subdue their victims and finally victimize them and how “The Victims” use strategies to cope with menace in order to survive. There are some passages quoted from the plays to facilitate the purpose of the second chapter. The objective in the third chapter is to define “Silences” and “Pauses” as theatrical techniques used in form of non-verbal communication between the characters. I will discuss, based on Peter Hall’s definition, how these techniques are significant in understanding a Pinter play for the readers and the actors who perform them on stage, and will further explore the function of “Silences” and “Pauses” and their distinction in the context of the plays in question in this essay.

This thesis focusses on the literary self-reflexivity of Birthday Letters, Ted Hughes's collection of poems addressed to his long-dead first wife, poet Sylvia Plath. By close attention to the language of select poems and a discussion of cross-referencing images and allusions across the volume, and intertextually, I argue that the collection is more self-consciously ordered and designed than the mainly biographical criticism the work has met with suggests. The thesis focusses on the poets' art rather than the biographical context of Birthday Letters, though it does not draw a neat distinction between their lives and their poetry - rather it demonstrates how Birthday Letters itself treats the relationship of art to life thematically. The introduction outlines the context of the volume's genesis and publication and the notions of poetry, myth and drama out of which Hughes works, and introduces the central metaphor of metamorphosis as figured in Ariel's song "Full Fathom Five" from The Tempest, as well as the importance of that play to Plath. Each of the chapters that follow focusses on a cluster of inter-related imagery through a discussion of four or five key poems. Chapter One examines Hughes's portrayal of himself as imprisoned by Plath's poetic portraits, and relates this to the recurring motifs of the snapshot and the Medusa myth. The poems discussed emphasize Hughes's consciousness of the metamorphic and "magical" relationship of art to life. The second chapter discusses Hughes's use of the myth of the labyrinth and the Minotaur, tracing it back to Plath's writings and reading, and pointing out its self-reflexivity: the labyrinth figures Hughes's own loss as well as the labyrinthine nature of writing. The third chapter considers the themes of possession and loss, and how they attach themselves to images of houses and jewels. Possession and loss tum, self-reflexively, upon issues of inheritance and remembrance, notably Hughes's inheritance of Plath's poetic legacy, and his remembrance of her and her poetry through his own poetry. The conclusion pursues connections between the observations made in the separate chapters, outlining the larger context out of which the poems emerge, and returning to the trope of metamorphosis as figured in "Full Fathom Five"

The aim of the thesis is to create a business plan, focusing on organizing children's birthday parties, social events and corporate parties, on the basis of which will be assessed the feasibility and economic advantage of the business plan. Thematically, the plan is divided into two parts. The first part covers the theoretical background, the definition of the business plan, the structure and principles of treatment, of which specific form is located in the following practical part. It contains a brief introduction, the company's mission, vision and objectives, description of business opportunities, defining the target and the total market including analysis of competition and marketing strategy. All previous points summarize the numerical form of the financial plan in three variants of development, the essence of which is to objectively assess the financial burden of the project. At the end of the thesis is the SWOT analysis, the potential risks of the project including the design of countermeasures to eliminate these effects. The whole thesis is finished with conclusion and evaluation of the business plan.

Willa Cather believed literature and journalism were separate and unequal genres. During her decade in Pittsburgh (1896-1906), as she gained recognition as a literary artist, she increasingly censored her early journalism and apprentice fiction. My dissertation promotes the recovery of these writings, especially the unsigned and pseudonymous pieces contained in two affiliated journals she served as an editor: Home Monthly the National Stockman and Farmer. My first chapter describes more then forty additional items from Home Monthly and the Stockman, including poetry, short fiction, and editorials. Annotated tables of contents and contributors' lists for both journals (1896-97) and maps and period photographs are offered in appendices.<br>Employing the methodology of New Historicism, my dissertation returns little regarded works to their approximate contexts of publication. Chapter 2 reads Cather's story "The Conversion of Sun Loo" (1900) as part of the debate over proselytizing the Chinese within the Library, a Pittsburgh magazine whose brief life (Spring and Summer of 1900) coincided with the Boxer rebellion in North China. "Sum Loo," it argues, is a satire upon recent events linking China and Pittsburgh's small Chinese colony.<br>The third chapter recovers a journalistic prototype for a story Cather held among her most "literary." Although Cather preferred to say "Paul's Case" (1905) was inspired by her teaching experience, she borrowed its plot from the city papers of November 1902, which reported the theft of $1,500 from the offices of the Denny Estate by two Pittsburgh boys. This chapter examines not only Cather's adaptation of extra-literary sources, but also her ambivalence toward her first career in journalism.<br>The final chapter concerns two late novellas, "Uncle Valentine" (1922) and "Double Birthday" (1929), written more than a decade after Cather's last physical visit to the city. Both use memories of Pittsburgh and Allegheny City at the turn of the century to attack suburbanization and class stratification, twin problems that she thought were eroding the nation's social fabric in the 1920s. / McAnulty College and Graduate School of Liberal Arts; / English / PhD; / Dissertation;

Vehicular communication technologies, also called Vehicle-to-everything (V2X) systems, are expected to become common in the future, providing better effciency and safety in transportation. This envisioned large-scale deployment, however, critically depends on addressing some requirements. For example, to prevent abuse by drivers, messages exchanged among authorized vehicles must be authenticated, which implies the need of a Vehicular Public Key Infrastructure (VPKI). Unlike traditional Public Key Infrastructures (PKIs), though, VPKIs are also expected to preserve the drivers\' privacy; in particular, neither eavesdroppers or system entities should be able to easily identify or track the movements of vehicles using non-revoked certificates. One promising VPKI solution, which copes with such requirements and is among the main candidates for standardization in the United States and Europe, is Security Credential Management System (SCMS). In this thesis, aiming to address shortcomings identified in the SCMS architecture, three main contributions are provided. First, a mechanism for improving the exibility of revocation is described, allowing certificates and their owner\'s privacy to be temporarily revoked in an eficient manner; this functionality is useful, for example, in case a software malfunction is detected and a patch still needs to be released. Second, two birthday attacks against SCMS\'s certificate revocation process are detailed and then fixed, thus preventing the system\'s security degradation with the number of issued and revoked certificates. Finally, a method is proposed which simplifies SCMS\'s system architecture, removing the need for the so-called Linkage Authorities (LAs); this not only reduces the cost for SCMS\'s deployment, but also improves its security and privacy due to the removal of one potential point of failure/collusion. / Espera-se que as tecnologias de comunicação veicular, também chamadas de sistemas V2X (Vehicle-to-everything, em inglês), se tornem comuns no futuro, proporcionando melhor eficiência e segurança no transporte. Essa implantação planejada em larga escala, no entanto, depende criticamente de abordar alguns requisitos. Por exemplo, para prevenir abusos por motoristas, mensagens trocadas entre veículos autorizados devem ser autenticadas, o que implica na necessidade de uma Infraestrutura de Chaves Públicas Veicular (VPKI, do inglês, Vehicular Public Key Infrastructure). Diferente de Infraestruturas de Chaves Públicas (ICPs) tradicionais, porém, é esperado também que as VPKIs preservem a privacidade dos motoristas; em particular, que nem bisbilhoteiros, nem entidades do sistema possam identificar veículos ou rastrear seus movimentos facilmente utilizando certificados n~ao revogados. Uma solução promissora para VPKI, que lida com tais requisitos e está entre os principais candidatos para padronização nos Estados Unidos e na Europa é o Sistema de gerenciamento de credenciais de segurança (SCMS, do inglês, Security Credential Management System). Nessa dissertação, com o objetivo de abordar deficiências identificadas na arquitetura do SCMS, são fornecidas três contribuições principais. Primeiro, um mecanismo para melhorar a exibilidade do processo de revogação é descrito, permitindo que certificados e a privacidade de seus proprietários sejam revogados temporariamente de maneira eficiente; essa funcionalidade é útil, por exemplo, em caso de uma falha de software ser detectada e ser necessário a liberação de uma correção. Em segundo lugar, dois ataques do aniversário contra o processo de revogação do SCMS são detalhados e posteriormente corrigidos, assim, prevenindo a degradação de segurança do sistema com o número de certificados emitidos e revogados. Por fim, é proposto um método que simplifica a arquitetura do sistema SCMS, removendo a necessidade das chamadas Autoridades de Ligação (LAs, do inglês, Linkage Authorites); o que não só reduz o custo de implantação do SCMS, mas também aumenta sua segurança e privacidade devido à remoção de um potencial ponto de falha/conluio.

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This study takes as its focus Ted Hughes’s composition techniques throughout his career, arguing that his self-conscious experimentation with the processes by which he wrote affected the style and subject matter of his work. Hughes’s poetry has lent itself to a number of familiar critical approaches, focusing on his preoccupation with mythology, his interaction with the natural world and his creative partnership with his first wife, Sylvia Plath. Yet no study, until now, has looked systematically at his literary drafts and the extent to which Hughes’s method of composition radically altered during his writing career. Archive material at Emory University, accessible since 2000, and new archive materials held at the British Library and made available for study for the first time in 2010, have opened up possibilities for much greater depth of research into Hughes’s writing processes and the birth and evolution of individual poems. By engaging with these materials, my research complements new studies which are tackling under-examined areas of Hughes’s work, whilst contributing more broadly to an increased awareness of the central importance of archival work in the study of literature. Literary manuscript drafts have often been used to study writers whose writing methods consciously foreground the drafting process. Whilst Hughes has not previously been considered in this light, my original investigations into his archival materials reveal a poet for whom the nature of the compositional process was a central concern which defines and redefines his poetry across his career.