Formal Specification and Verification of Fully Asynchronous Implementations of the Data Encryption Standard

This paper presents two formal models of the Data Encryption Standard (DES), a first using the international standard LOTOS, and a second using the more recent process calculus LNT. Both models encode the DES in the style of asynchronous circuits, i.e., the data-flow blocks of the DES algorithm are represented by processes communicating via rendezvous. To ensure correctness of the models, several techniques have been applied, including model checking, equivalence checking, and comparing the results produced by a prototype automatically generated from the formal model with those of existing implementations of the DES. The complete code of the models is provided as appendices and also available on the website of the CADP verification toolbox.Comment: In Proceedings MARS 2015, arXiv:1511.0252

Datasikkerhet i sikkerhetsinstrumenterte systemer

Instrumenteringssystemer har tradisjonelt vært separate systemer og har krevd lite fokus på datasikkerhet. I senere tid har økende bruk av standard kommunikasjonsprotokoller, kommunikasjon over lange avstander, samt utstyr koblet til internett, gjort kommunikasjon med instrumenteringssystemer betydelig mer utsatt for nettverksangrep enn tidligere. Det er et krav at eventuelle tiltak for datasikkerhet (security) ikke kommer på bekostning av kontrollsystemets sikkerhetsfunksjoner (safety). Formålet med denne oppgaven er å kartlegge hvilke krav som stilles til kommunikasjon mellom kontrollrom og sikkerhetskritiske styringsenheter i felt, og hvordan dette kan kombineres med tiltak for å sikre kommunikasjonen mot nettverksangrep

Isogeny-based post-quantum key exchange protocols

The goal of this project is to understand and analyze the supersingular isogeny Diffie Hellman (SIDH), a post-quantum key exchange protocol which security lies on the isogeny-finding problem between supersingular elliptic curves. In order to do so, we first introduce the reader to cryptography focusing on key agreement protocols and motivate the rise of post-quantum cryptography as a necessity with the existence of the model of quantum computation. We review some of the known attacks on the SIDH and finally study some algorithmic aspects to understand how the protocol can be implemented

Post-Heideggerian Drifts: From Object-Oriented-Ontology Worldlessness to Post-Nihilist Worldings

This paper rethinks the dynamics of what Heidegger called the modern Gestell ”“ i.e. dynamics behind the fulfilment of nihilism ”“ as that of an “unworlding” on whose subsequent “worldlessness” today’s Object-Oriented Ontology may be said to build. Also, it questions whether Heidegger’s early-Greek-oriented thought on being does not actually solicit an altogether different drift on the horizon of the possible, namely: that of thinking and re-experiencing dwelling in terms of retrieved “worldness.” Lastly, it reflects on the conditions of possibility that such dwelling, and its concomitant “worldings,” must meet, in dialogue with Heidegger, present-day animism studies, and non-religious Greek views on the sacred and the divine, in connection to which it articulates, and endorses, the concept of post-nihilism in contraposition to today’s nihilist philosophical wanderings

Patriots and Fribbles: Effeminacy and Politics in the Literature of the Seven Years’ War and its Aftermath, 1756-1774

This thesis examines British cultural anxieties surrounding effeminacy and foreignness in the literature of the Seven Years’ War and its aftermath, c. 1756-1772. Primarily, it is concerned with assessing how anxiety regarding effeminacy presents as a discourse of crisis within a diverse set of discrete, though densely worked debates, surrounding authorial independence, freedom of the press, the electorate’s right to free elections, and the aesthetic experience of the sublime. All of these debates shape emergent formulations of patriotism at mid-century. Chapter One considers how the conflation of xenophobia and effeminophobia operates as a rhetorical device in the poetry of the satirist Charles Churchill (1731-1764). Reading Churchill’s anti-Ossian poetry, I argue that the portrayal of the Highlander as heterosexually effeminate enables the articulation of patriotism as heteroerotic balance. Building on this, Chapter Two analyses the sexual and political controversies that mark the early career of the radical Whig politician John Wilkes (1725-1795). Taking one key narrative of Wilkite opposition, namely, the resistance in The North Briton to the excise on cider, Chapter Three shows how the defence of a gentleman’s property provokes debates about the nature of privacy and publicity that enfold into the fraught discourse on effeminacy. The second part of this chapter considers the successes and failures of two political essay-sheets, The Test and The Auditor, which were written by Arthur Murphy during the opening and closing stages of the Seven Years’ War. The final chapter reads the early political writings of Edmund Burke (1729- 1797) in the context of the fractious debates engendered by Wilkes’s attempts at re-entry to political life in the late 1760s. I argue that Burke’s understanding of the sublime offers an aesthetic response to effeminophobic and xenophobic anxieties, which has consequences for the longer history of British imperialism

Patriots and Fribbles: Effeminacy and Politics in the Literature of the Seven Years’ War and its Aftermath, 1756-1774

This thesis examines British cultural anxieties surrounding effeminacy and foreignness in the literature of the Seven Years’ War and its aftermath, c. 1756-1772. Primarily, it is concerned with assessing how anxiety regarding effeminacy presents as a discourse of crisis within a diverse set of discrete, though densely worked debates, surrounding authorial independence, freedom of the press, the electorate’s right to free elections, and the aesthetic experience of the sublime. All of these debates shape emergent formulations of patriotism at mid-century. Chapter One considers how the conflation of xenophobia and effeminophobia operates as a rhetorical device in the poetry of the satirist Charles Churchill (1731-1764). Reading Churchill’s anti-Ossian poetry, I argue that the portrayal of the Highlander as heterosexually effeminate enables the articulation of patriotism as heteroerotic balance. Building on this, Chapter Two analyses the sexual and political controversies that mark the early career of the radical Whig politician John Wilkes (1725-1795). Taking one key narrative of Wilkite opposition, namely, the resistance in The North Briton to the excise on cider, Chapter Three shows how the defence of a gentleman’s property provokes debates about the nature of privacy and publicity that enfold into the fraught discourse on effeminacy. The second part of this chapter considers the successes and failures of two political essay-sheets, The Test and The Auditor, which were written by Arthur Murphy during the opening and closing stages of the Seven Years’ War. The final chapter reads the early political writings of Edmund Burke (1729- 1797) in the context of the fractious debates engendered by Wilkes’s attempts at re-entry to political life in the late 1760s. I argue that Burke’s understanding of the sublime offers an aesthetic response to effeminophobic and xenophobic anxieties, which has consequences for the longer history of British imperialism

Commerce, finance and statecraft

In the seventeenth and eighteenth centuries, historians of England pioneered a series of new approaches to the history of economic policy. Commerce, finance and statecraft charts the development of these forms of writing and explores the role they played in the period's economic, political and historiographical thought. Through doing so, the book makes a significant intervention in the study of historiography, and provides an original account of early-modern and Enlightenment history. A broad selection of historical writing is discussed, ranging from the work of Francis Bacon and William Camden in the Jacobean era, through a series of accounts shaped by the English Civil War and the party-political conflicts that followed it, to the eighteenth-century's major account of British history: David Hume's History of England. Particular attention is paid to the historiographical context in which historians worked and the various ways they copied, adapted and contested one another's narratives. Such an approach enables the study to demonstrate that historical writing was the site of a wide-ranging, politically charged debate concerning the relationship that existed – and should have existed – between government and commerce at various moments in England’s past

Algorithms for Solving Linear and Polynomial Systems of Equations over Finite Fields with Applications to Cryptanalysis

This dissertation contains algorithms for solving linear and polynomial systems of equations over GF(2). The objective is to provide fast and exact tools for algebraic cryptanalysis and other applications. Accordingly, it is divided into two parts. The first part deals with polynomial systems. Chapter 2 contains a successful cryptanalysis of Keeloq, the block cipher used in nearly all luxury automobiles. The attack is more than 16,000 times faster than brute force, but queries 0.62 × 2^32 plaintexts. The polynomial systems of equations arising from that cryptanalysis were solved via SAT-solvers. Therefore, Chapter 3 introduces a new method of solving polynomial systems of equations by converting them into CNF-SAT problems and using a SAT-solver. Finally, Chapter 4 contains a discussion on how SAT-solvers work internally. The second part deals with linear systems over GF(2), and other small fields (and rings). These occur in cryptanalysis when using the XL algorithm, which converts polynomial systems into larger linear systems. We introduce a new complexity model and data structures for GF(2)-matrix operations. This is discussed in Appendix B but applies to all of Part II. Chapter 5 contains an analysis of "the Method of Four Russians" for multiplication and a variant for matrix inversion, which is log n faster than Gaussian Elimination, and can be combined with Strassen-like algorithms. Chapter 6 contains an algorithm for accelerating matrix multiplication over small finite fields. It is feasible but the memory cost is so high that it is mostly of theoretical interest. Appendix A contains some discussion of GF(2)-linear algebra and how it differs from linear algebra in R and C. Appendix C discusses algorithms faster than Strassen's algorithm, and contains proofs that matrix multiplication, matrix squaring, triangular matrix inversion, LUP-factorization, general matrix in- version and the taking of determinants, are equicomplex. These proofs are already known, but are here gathered into one place in the same notation