Strong authentication using dynamic hashing and steganography

Indexing techniques such as extendible hashing and B-trees are widely used to store, retrieve and search for data on files in most file systems. These techniques have been comprehensively explored to enhance the data structure for increasing the faster access to file contents. Extendible hashing is a dynamic hashing technique which handles dynamic files that keep changing in size. Traditional extendible hashing uses bit addresses to hash the data to buckets and restricts the directory size to be a power of 2 which has corresponding complications in implementation. Restriction on directory size also results in uneven distribution of data which increases the possibility of overflows. This in turn increases the cost of index maintenance. In this paper, an efficient and simpler to implement variation of Extendible hashing method named Bit-Less Extendible Hashing (BLEH) for dynamic files is proposed. The proposed method eliminates the need for binary representation of the hash address which reduces the complexity of implementation. Furthermore, it eliminates the need for the directory size to be a power of 2 providing flexibility in the choice of initial directory size. The experimental results show that the proposed method provides better performance in terms of split count upon insertion when compared to the traditional extendible hashing method with good space utilization.

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Dynamic hashing strategies

Lecture Notes in Computer Science - Mathematical Foundations of Computer Science 1990 ◽

10.1007/bfb0029597 ◽

2005 ◽

pp. 76-87 ◽

Cited By ~ 1

Author(s):

Friedhelm Meyer auf der Heide

Keyword(s):

Dynamic Hashing

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Digital Trees and Memoryless Sources: from Arithmetics to Analysis

Discrete Mathematics & Theoretical Computer Science ◽

10.46298/dmtcs.2799 ◽

2010 ◽

Vol DMTCS Proceedings vol. AM,... (Proceedings) ◽

Cited By ~ 1

Author(s):

Philippe Flajolet ◽

Mathieu Roux ◽

Brigitte Vallée

Keyword(s):

Probabilistic Models ◽

Asymptotic Form ◽

Leader Election ◽

Text Compression ◽

Digital Trees ◽

Arithmetic Properties ◽

International Audience ◽

Error Terms ◽

Dynamic Hashing

International audience Digital trees, also known as $\textit{"tries''}$, are fundamental to a number of algorithmic schemes, including radix-based searching and sorting, lossless text compression, dynamic hashing algorithms, communication protocols of the tree or stack type, distributed leader election, and so on. This extended abstract develops the asymptotic form of expectations of the main parameters of interest, such as tree size and path length. The analysis is conducted under the simplest of all probabilistic models; namely, the $\textit{memoryless source}$, under which letters that data items are comprised of are drawn independently from a fixed (finite) probability distribution. The precise asymptotic structure of the parameters' expectations is shown to depend on fine singular properties in the complex plane of a ubiquitous $\textit{Dirichlet series}$. Consequences include the characterization of a broad range of asymptotic regimes for error terms associated with trie parameters, as well as a classification that depends on specific $\textit{arithmetic properties}$, especially irrationality measures, of the sources under consideration.

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