A high-speed integrated circuit with applications to RSA Cryptography

Merged with duplicate record 10026.1/833 on 01.02.2017 by CS (TIS)The rapid growth in the use of computers and networks in government, commercial and private communications systems has led to an increasing need for these systems to be secure against unauthorised access and eavesdropping. To this end, modern computer security systems employ public-key ciphers, of which probably the most well known is the RSA ciphersystem, to provide both secrecy and authentication facilities. The basic RSA cryptographic operation is a modular exponentiation where the modulus and exponent are integers typically greater than 500 bits long. Therefore, to obtain reasonable encryption rates using the RSA cipher requires that it be implemented in hardware. This thesis presents the design of a high-performance VLSI device, called the WHiSpER chip, that can perform the modular exponentiations required by the RSA cryptosystem for moduli and exponents up to 506 bits long. The design has an expected throughput in excess of 64kbit/s making it attractive for use both as a general RSA processor within the security function provider of a security system, and for direct use on moderate-speed public communication networks such as ISDN. The thesis investigates the low-level techniques used for implementing high-speed arithmetic hardware in general, and reviews the methods used by designers of existing modular multiplication/exponentiation circuits with respect to circuit speed and efficiency. A new modular multiplication algorithm, MMDDAMMM, based on Montgomery arithmetic, together with an efficient multiplier architecture, are proposed that remove the speed bottleneck of previous designs. Finally, the implementation of the new algorithm and architecture within the WHiSpER chip is detailed, along with a discussion of the application of the chip to ciphering and key generation

Algorithmic analysis of parity games

Parity games are discrete infinite games of two players with complete information. There are two main motivations to study parity games. Firstly the problem of deciding a winner in a parity game is polynomially equivalent to the modal µ-calculus model checking, and therefore is very important in the field of computer aided verification. Secondly it is the intriguing status of parity games from the point of view of complexity theory. Solving parity games is one of the few natural problems in the class NP∩co-NP (even in UP∩co-UP), and there is no known polynomial time algorithm, despite the substantial amount of effort to find one. In this thesis we add to the body of work on parity games. We start by presenting parity games and explaining the concepts behind them, giving a survey of known algorithms, and show their relationship to other problems. In the second part of the thesis we want to answer the following question: Are there classes of graphs on which we can solve parity games in polyno

On Gabbay's temporal fixed point operator

AbstractWe discuss the temporal logic “USF”, involving Until, Since and the fixed point operator ϑ of Gabbay, with semantics over the natural numbers. We show that any formula not involving Until is equivalent to one without nested fixed point operators. We then prove that USF has expressive power matching that of the monadic second-order logic S1S. The proof shows that any USF-formula is equivalent to one with at most two nested fixed point operators — i.e., no branch of its formation tree has more than two ϑ's. We then axiomatise USF and prove that it is decidable, with PSPACE-complete satisfiability problem. Finally, we discuss an application of these results to the executable temporal logic system “MetateM”

Foundations of secure computation

Issued as Workshop proceedings and Final report, Project no. G-36-61

Parallel computation on sparse networks of processors

SIGLELD:D48226/84 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Reporting on contested territory: television news coverage of the Israel-Palestine conflict

This thesis is an examination of how British television news reported on the Peace Accords signed between Israeli and Palestinian negotiators at the Wye River Plantation, Maryland USA in October 1998. The research involves three elements. Firstly a review of the historiography of the conflict which sketches out the range of views on the history and origins of the dispute. Secondly a content analysis of the peace negotiations themselves. This examines how journalists drew on the range of views present in the historiography in order to contextualise coverage and provide explanations for the conflict. Thirdly the thesis looks at the various factors in production which influence the construction of news in this area, and links this to theoretical debates in the area

Computational geometry through the information lens

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 111-117).This thesis revisits classic problems in computational geometry from the modern algorithmic perspective of exploiting the bounded precision of the input. In one dimension, this viewpoint has taken over as the standard model of computation, and has led to a powerful suite of techniques that constitute a mature field of research. In two or more dimensions, we have seen great success in understanding orthogonal problems, which decompose naturally into one dimensional problems. However, problems of a nonorthogonal nature, the core of computational geometry, have remained uncracked for many years despite extensive effort. For example, Willard asked in SODA'92 for a o(nlg n) algorithm for Voronoi diagrams. Despite growing interest in the problem, it was not successfully solved until this thesis. Formally, let w be the number of bits in a computer word, and consider n points with O(w)-bit rational coordinates. This thesis describes: * a data structure for 2-d point location with O(n) space, and 0( ... )query time. * randomized algorithms with running time 9 ... ) for 3-d convex hull, 2-d Voronoi diagram, 2-d line segment intersection, and a variety of related problems. * a data structure for 2-d dynamic convex hull, with O ( ... )query time, and O ( ... ) update time. More generally, this thesis develops a suite of techniques for exploiting bounded precision in geometric problems, hopefully laying the foundations for a rejuvenated research direction.by Mihai Pǎtraşcu.S.M