We propose a novel methodology to design Block Cipher functions. This methodology is illustrated with the design of a specific block cipher function Maya. Our design philosophy is to derive the SBoxes themselves from the secret key. This makes breaking any round function equivalent to guessing all the key-bits. Advantages of our design include much larger key sizes in relation to the block size...

In a 4-(12, 6, 4) design a block is either disjoint from one other block or it has five points in common with one other block. For a 4-(12, 6, 4) design with a pair of blocks of the second type it is shown that· another thirty blocks of the design can be completed in a unique way and these thirty blocks contain a copy of a 3-(10, 4, 1) design.

The origin of the highest-energy cosmic rays remains a mystery. The lack of a high energy cutoff in the cosmic ray spectrum together with an apparently isotropic distribution of arrival directions have strongly constrained most models proposed for the generation of these particles. An overview of the present state of theoretical proposals is presented. Astrophysical accelerators as well as top-...

Block ramps are hydraulic structures which are commonly used in river restoration projects. Especially in the last few decades, the use of this type of structures have become more and more popular. They furnish a correct balance between the hydraulic functioning and the environmental care, as they minimize the impact on the environment in which they are located. In addition, they can be conside...

In a recent article in the Canadian Journal of Forest Research (Ericsson 1997) discussed the use of postblocking in the analysis of progeny trials. We would like to comment on three aspects of this paper: The idea of postblocking a trial is well known and has been used to advantage by Patterson and Hunter (1983) as a means of studying the nature of spatial variation at trial sites. A more detai...

SUMMARY. In a parallel line assay, there are three treatment contrasts of major importance. Block designs allowing the estimability of all the three contrasts free from block effects, called L-designs, necessarily have the block sizes even. For odd block sizes, we provide here a class of highly efficient designs, called nearly L-designs. These nearly L-designs have been constructed by establish...

This work presents a recursive construction for simple t-designs using resolutions of the ingredient designs. The result extends a construction of t-designs in our recent paper [39]. Essentially, the method in [39] describes the blocks of a constructed design as a collection of block unions from a number of appropriate pairs of disjoint ingredient designs. Now, if some pairs of these ingredient...

1. Introduction. Since this is a survey paper on blocking sets in block designs, the definition of a block design seems an appropriate beginning. So, here goes. A block design of index A is a pair (p, B), where P is a finite set (the elements of which are sometimes called points) and B is a collection of subsets of P (all of the same size k) called blocks such that every pair of distinct elemen...