Master of Science / Department of Computer Science / Arslan Munir / Modern automobiles incorporate a network of electronic control units (ECUs) that provides a range of features such as safety, driver assistance, infotainment. Such network of ECUs in a vehicle are connected to each other through buses, forming interconnections called intra-vehicle network. Bus technologies that are widely used in modern day automobiles are controller area network (CAN), local interconnect network (LIN), and media oriented systems transport (MOST). These bus technologies, however, do not possess any security or dependability features, and thus are susceptible to vulnerabilities. Such vulnerabilities allow attackers to mount passive attacks (e.g., snooping) and/or active attacks (e.g., fault injection). In this study, we propose a scheme for secure authentication of automotive ECUs. Our proposed scheme ensures that only authenticated ECUs can participate in communication over the intra-vehicle network/bus. ECU authentication is carried out using certificate-based authentication which is implemented using elliptic curve cryptography (ECC). The study also proposes a symmetric (session) key-establishment mechanism within intra-vehicular network to establish a common symmetric (session) key for all ECUs to communicate over the network. The key-establishment mechanism removes the need of storing symmetric keys in ECU memory permanently. The study incorporates key refreshment by assigning a certain lifetime/timeframe period to symmetric (session) key and then regularly updates session key after the expiration of each lifetime. Our proposed method provides confidentiality and integrity in intra-vehicle ECU communication without violating safety and real-time constraints of the vehicle. Our approach leverages multi-core ECUs to provide fault-tolerance by using redundant multi-threading (FT-RMT), performs quick error detection (FT-QED) and accelerate performance using lightweight checkpointing (CP).

Confusion and Diffusion are two properties of a secure cipher, identified by Claude Shannon. Confusion refers to making the relationship between the ciphertext and the symmetric key as complex and involved as possible. We try to achieve more confusion by creating a ciphertext of different length for a given plaintext when key is changed. As per our knowledge, all the existing symmetric encryption techniques will generate cipher text of same length for a given plaintext with different keys. The technique we are implementing here, will create ciphertext with different length for a given plaintext if we change the appropriate values in the key. This symmetric encryption technique will also possibly make the recovery of key very hard for the attacker.

No description available.

archives@tulane.edu / This thesis examines the geometry and combinatorics of Borel subgroup orbits in classical symmetric spaces G/L where G is complex linear algebraic group and L is a Levi factor of a maximal parabolic subgroup P in G. In these cases, known as symmetric spaces of Hermitian type, we show that the canonical projection map $\pi : G/L \to G/P$ has the structure of an affine bundle. This fact yields a cell decomposition of G/L as well as isomorphisms of the cohomology and Chow rings of G/L and G/P, and motivates the study of the Borel orbits of G/L in relation to their images under the equivariant map $\pi$. For all of the cases of interest (symmetric spaces of types AIII, CI, DIII and BDI), G/P is a Grassmannian variety with Borel orbits called Schubert cells. Borel orbits of most of these symmetric spaces are parametrized by combinatorial objects called clans. This thesis provides enumerative formulae for the orbits in type CI, DIII and BDI , and gives bijections between sets of clans and other families of objects such as (fixed-point free) partial involutions, rook placements, and set partitions. Clans come with a poset structure given by the closure containment relation of the corresponding Borel orbits, and we supply rank polynomials for these posets in types CI and DIII. We give a combinatorial description of the closure order relations in types AIII, CI, and DIII which allows us to resolve part of a conjecture of Wyser on the restriction of this order from type AIII to other types. In the course of this description, we identify the preimages of Schubert cells under the map \pi as collections of clans called “sects.” Our combinatorial description of the sects identifies Borel orbits whose closures generate the Chow ring of G/L and reveals additional structure in the closure poset of clans. In particular, the preimage of the largest Schubert cell coincides variously with well-known posets of matrix Schubert varieties and congruence Borel orbit closures. Furthermore, we show that in type AIII the closure order restricted to a given sect can be described combinatorially in terms of “rank tableaux.” / 0 / Aram Bingham

No description available.

<p> A family of symmetric distributions is introduced. The means, variances and covariances of ordered observations from the family are calculated. The best linear unbiased estimators of the mean and standard deviation are constructed for complete and censored samples. A computer technique is developed to evaluate range-dependent double integrals. </p> / Thesis / Master of Science (MSc)

The original Macdonald polynomials P_μ form a basis for the vector space of symmetric functions which specializes to several of the common bases such as the monomial, Schur, and elementary bases. There are a number of different types of Macdonald polynomials obtained from the original P_μ through a combination of algebraic and plethystic transformations one of which is the modified Macdonald polynomial H̃_μ. In this dissertation, we study a certain specialization F̃_μ(q,t) which is the coefficient of x₁x₂…x_N in H̃_μ and also the Hilbert series of the Garsia-Haiman module M_μ. Haglund found a combinatorial formula expressing F̃_μ as a sum of n! objects weighted by two statistics. Using this formula we prove a q,t-analogue of the hook-length formula for hook shapes. We establish several new combinatorial operations on the fillings which generate F̃_μ. These operations are used to prove a series of recursions and divisibility properties for F̃_μ. / Ph. D.

The process of factorizing a symmetric matrix using the Cholesky (LLT ) or indefinite (LDLT ) factorization of A allows the efficient solution of systems Ax = b when A is symmetric. This thesis describes the development of new serial and parallel techniques for this problem and demonstrates them in the setting of interior point methods. In serial, the effects of various scalings are reported, and a fast and robust mixed precision sparse solver is developed. In parallel, DAG-driven dense and sparse factorizations are developed for the positive definite case. These achieve performance comparable with other world-leading implementations using a novel algorithm in the same family as those given by Buttari et al. for the dense problem. Performance of these techniques in the context of an interior point method is assessed.

Neste trabalho, fazemos um estudo dos campos tensoriais antissimétricos em geral e, em particular, do campo tensorial antissimétrico de ordem dois. Utilizando o método de quantização BRST-BFV para teorias redutíveis no formalismo hamiltoniano, mostramos a equivalência quântica do campo tensorial antissimétrico de ordem dois não-massivo ao campo escalar em 4 dimensões e ao campo vetorial no gauge de Lorentz em 5 dimensões. Também é mostrada a equivalência entre as formulações de 1ª e 2ª ordem do campo tensorial antissimétrico de ordem dois. Por fim, é efetuada a quantização BRST-BFV de um modelo de partícula relativística com spin com duas supersimetrias acrescido de um termo Chern-Simons, mostrando que a amplitude de transição obtida equivale à amplitude de transição do \"rotacional\" de um campo tensorial antissimétrico de ordem qualquer. O caso massivo também é tratado brevemente. / In this work, we make a study of anti symmetric tensor fields in general, and, in particular, of the anti symmetric tensor fields of order two. Using the BRST-BFV quantization method for reducible theories in the Hamiltonian formalism, we show the quantum equivalence of the massless anti symmetric tensor field of order two to the scalar field in 4 dimensions, and to the vector field in the Lorentz gauge in 5 dimensions. It is also shown the quantum equivalence between the 1st and 2nd order formulations for the anti symmetric tensor field of order two. Finally, it is made the BRST-BFV quantization of a model of relativistic spinning particle with two super symmetries with a Chern-Simons term, showing that the transition amplitude obtained is equivalent to the transition amplitude for the field strength of an anti symmetric tensor field of any order. The massive case is also treated in breaf.

Neste trabalho, fazemos um estudo dos campos tensoriais antissimétricos em geral e, em particular, do campo tensorial antissimétrico de ordem dois. Utilizando o método de quantização BRST-BFV para teorias redutíveis no formalismo hamiltoniano, mostramos a equivalência quântica do campo tensorial antissimétrico de ordem dois não-massivo ao campo escalar em 4 dimensões e ao campo vetorial no gauge de Lorentz em 5 dimensões. Também é mostrada a equivalência entre as formulações de 1ª e 2ª ordem do campo tensorial antissimétrico de ordem dois. Por fim, é efetuada a quantização BRST-BFV de um modelo de partícula relativística com spin com duas supersimetrias acrescido de um termo Chern-Simons, mostrando que a amplitude de transição obtida equivale à amplitude de transição do \"rotacional\" de um campo tensorial antissimétrico de ordem qualquer. O caso massivo também é tratado brevemente. / In this work, we make a study of anti symmetric tensor fields in general, and, in particular, of the anti symmetric tensor fields of order two. Using the BRST-BFV quantization method for reducible theories in the Hamiltonian formalism, we show the quantum equivalence of the massless anti symmetric tensor field of order two to the scalar field in 4 dimensions, and to the vector field in the Lorentz gauge in 5 dimensions. It is also shown the quantum equivalence between the 1st and 2nd order formulations for the anti symmetric tensor field of order two. Finally, it is made the BRST-BFV quantization of a model of relativistic spinning particle with two super symmetries with a Chern-Simons term, showing that the transition amplitude obtained is equivalent to the transition amplitude for the field strength of an anti symmetric tensor field of any order. The massive case is also treated in breaf.