The main objective of this thesis is to examine the trade-offs between security and efficiency within symmetric ciphers. This includes the influence that block ciphers have on the new generation of word-based stream ciphers. By incorporating block-cipher like components into their designs, word-based stream ciphers have experienced hundreds-fold improvement in speed over bit-based stream cipher...

Probabilistic methods have been developed that estimate the site-specific probabilities of the amino acids in sequences likely to fold to a particular target structure, and such information can be used to guide the de novo design of proteins and to probe sequence variability. An extension of these methods for the design of symmetric homo-oligomeric quaternary structures is presented. The theory...

This chapter presents two fuzzy adaptive variable structure controllers for a class of uncertain multiinput multi-output nonlinear systems with actuator nonlinearities (i.e. with sector nonlinearities and dead-zones). The design of the first controller concerns systems with symmetric and positive definite control-gain matrix, while the design of the second one is extended to the case of non-sym...

Let X be a pseudocyclic association scheme in which all the nontrivial relations are strongly regular graphs with the same eigenvalues. We prove that the principal part of the first eigenmatrix of X is a linear combination of an incidence matrix of a symmetric design and the all-ones matrix. Amorphous pseudocyclic association schemes are examples of such association schemes whose associated sym...

In a recent paper, Pawale [22] investigated quasi-symmetric 2-(v, k, λ) designs with intersection numbers x > 0 and y = x+ 2 with λ > 1 and showed that under these conditions either λ = x + 1 or λ = x + 2, or D is a design with parameters given in the form of an explicit table, or the complement of one of these designs. In this paper, quasi-symmetric designs with y−x = 3 are investigated. It is...

We report the analysis, design, fabrication and experimental characterization of novel subwavelength computer-generated holograms that produce uniform symmetric spot array. We distinguish between a polarization-sensitive and polarization-insensitive far-field reconstruction and show that a linearly polarized incident illumination is required in the former case in order to generate a symmetric r...

This paper describes the CAST design procedure for constructing a family of DES-like Substitution-Permutation Network (SPN) cryptosystems which appear to have good resistance to differential cryptanalysis, linear cryptanalysis, and related-key cryptanalysis, along with a number of other desirable cryptographic properties. Details of the design choices in the procedure are given, including those...

We study a class of procurement auctions with a budget constraint, where an auctioneer is interested in buying resources or services from a set of agents. Ideally, the auctioneer would like to select a subset of the resources so as to maximize his valuation function, without exceeding a given budget. As the resources are owned by strategic agents however, our overall goal is to design mechanism...

A , (m  ) n threshold secret sharing scheme is a method for distributing a secret amongst a group of participants. In a , (m  ) n threshold secret sharing scheme any m participants recover the secret, but no ) 1 (  m participants can [6]. Each of participants is allocated a share of the secret. The secret can only be reconstructed when the shares are combined together [2]. In this paper, we ...

Abstract—A novel approach for the design of image encryption system based on one stage of 3D photonic bandgap structure is proposed. Using the Finite Integration Time Domain (FITD) method, the performance of the proposed design is optimized through the utilization of the reflection properties from 3D photonic bandgap structure while maintaining constant phase encoding. To demonstrate the robust...