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A Spatial Analysis Of Variance Applied To Soil-Water Infiltration, C Gotway, Noel A. Cressie
A Spatial Analysis Of Variance Applied To Soil-Water Infiltration, C Gotway, Noel A. Cressie
Faculty of Informatics - Papers (Archive)
A spatial analysis of variance uses the spatial dependence among the observations to modify the usual interference procedures associated with a statistical linear model. When spatial correlation is present, the usual tests for presence of treatment effects may no longer be valid, and erroneous conclusions may result from assuming that the usual F ratios are F distributed. This is demonstrated using a spatial analysis of soil-water infiltration data. Emphasis is placed on modeling the spatial dependence structure with geostatistical techniques, and this spatial dependence structure is then used to test hypotheses about fixed effects using a nested linear model. -Authors
Search Key Substitution In The Encipherment Of B-Trees, Thomas Hardjono, Jennifer Seberry
Search Key Substitution In The Encipherment Of B-Trees, Thomas Hardjono, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
This paper suggests an improvement to the scheme by Bayer and Metzger for the encipherment of B-Trees. Search keys are "disguised" instead of encrypted, and together with the data pointers and tree pointers which remain encrypted, prevents the opponent or attacker from recreating the correct shape of the B-Tree. Combinatorial block designs are used as a method to substitute the search keys contained within the nodes of the B-Tree. The substitution provides advantages in terms of the number of decryptions necessary to traverse the B-Tree, while the use of block designs are advantageous in terms of the small amount of …
Loki - A Cryptographic Primitive For Authentication And Secrecy Applications, Lawrence Brown, Josef Pieprzyk, Jennifer Seberry
Loki - A Cryptographic Primitive For Authentication And Secrecy Applications, Lawrence Brown, Josef Pieprzyk, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
This paper provides an overview of the LOKI encryption primitive which may be used to encrypt and decrypt a 64-bit block of data using a 64-bit key. It has been developed as a result of work analysing the existing DEA-1, with the aim of designing a new family of encryption primitives [Brow88], [BrSe89], [BrSe90], [PiFi88], [Piep89b], [Piep89a], [PiSe89]. Its overall structure has a broad resemblence to DEA-1 (see Fig. 1), however the detailed structure has been designed to remove operations which impede analysis or hinder efficient implementation, but which do not add to the cryptographic security of the algorithm. The …
Some Remarks On Authentication Systems, Martin Hg Anthony, Keith M. Martin, Jennifer Seberry, Peter Wild
Some Remarks On Authentication Systems, Martin Hg Anthony, Keith M. Martin, Jennifer Seberry, Peter Wild
Faculty of Informatics - Papers (Archive)
Brickell, Simmons and others have discussed doubly perfect authentication systems in which an opponent's chance of deceiving the receiver is a minimum for a given number of encoding rules. Brickell has shown that in some instances to achieve this minimum the system needs to have splitting. Such a system uses a larger message space. Motivated by Brickell's ideas we consider authentication systems with splitting and the problems of reducing the message space.
On The Design Of Permutation P In Des Type Cryptosystems, Lawrence Brown, Jennifer Seberry
On The Design Of Permutation P In Des Type Cryptosystems, Lawrence Brown, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
This paper reviews some possible design criteria for the permutation P in a DES style cryptosystem. These permutations provide the diffusion component in a substitution-permutation network. Some empirical rules which seem to account for the derivation of the permutation used in the DES are first presented. Then it is noted that these permutations may be regarded as latin-squares which link the outputs of S-boxes to their inputs at the next stage. A subset of these which perform well in a dependency analysis are then presented and suggested for use in future schemes.
Further Results On Base Sequences, Disjoint Complementary Sequences, Od(4t; T, T, T, T) And The Excess Of Hadamard Matrices, Christos Koukouvinos, Stratis Kounias, Jennifer Seberry
Further Results On Base Sequences, Disjoint Complementary Sequences, Od(4t; T, T, T, T) And The Excess Of Hadamard Matrices, Christos Koukouvinos, Stratis Kounias, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
We obtain new base sequences, that is four sequences of lengths m + p, m + p, m, m, with p odd, which have zero auto correlation function which can be used with Yang numbers and four disjoint complementary sequences (and matrices) with zero non-periodic (periodic) auto correlation function to form longer sequences. We give an alternate construction for T-sequences of length (4n + 3)(2m + p) where n is the length of a Yang nice sequence. These results are then used in the Goethals-Seidel or (Seberry) Wallis-Whiteman construction to determine eight possible decompositions into squares of (4n + 3) …
On The Products Of Hadamard Matrices, Williamson Matrices And Other Orthogonal Matrices Using M-Structures, Jennifer Seberry, Mieko Yamada
On The Products Of Hadamard Matrices, Williamson Matrices And Other Orthogonal Matrices Using M-Structures, Jennifer Seberry, Mieko Yamada
Faculty of Informatics - Papers (Archive)
The new concept of M-structures is used to unify and generalize a number of concepts in Hadamard matrices including Williamson matrices, Goethals-Seidel matrices, Wallis-Whiteman matrices and generalized quaternion matrices. The concept is used to find many new symmetric Williamson-type matrices, both in sets of four and eight, and many new Hadamard matrices. We give as corollaries "that the existence of Hadamard matrices of orders 4g and 4h implies the existence of an Hadamard matrix of older 8gh" and "the existence of Williamson type matrices of orders u and v implies the existence of Williamson type matrices of order 2uv". This …
Key Scheduling Des Type Cryptosystems, Lawrence Brown, Jennifer Seberry
Key Scheduling Des Type Cryptosystems, Lawrence Brown, Jennifer Seberry
Faculty of Informatics - Papers (Archive)
This paper reviews some possible design criteria for the key schedule in a DES style cryptosystem. The key schedule involves a Key Rotation component. and the permutation PC2. Together these provide for a diffusion of dependency of ciphertext bits on key bits. Some empirical rules which seem to account for the derivation of the key schedule used in the DES are first presented. A number of trials were run with various key schedules. and some further design rules were derived. An alternative form of key schedule was then tested. This used either a null PC2, or one in which permutations …