scholarly journals Collision-resistant hash function based on composition of functions

2011 ◽  
Vol Volume 14 - 2011 - Special... ◽  
Author(s):  
René Ndoundam ◽  
Juvet Karnel Sadie
Keyword(s):  
Hash Function ◽  
Contingency Tables ◽  
Three Dimensional ◽  
Hash Functions ◽  
Numerical Data ◽  
Fixed Size ◽  
Compression Function ◽  
Np Completeness ◽  
International Audience ◽  
Composition Of Functions

International audience A cryptographic hash function is a deterministic procedure that compresses an arbitrary block of numerical data and returns a fixed-size bit string. There exists many hash functions: MD5, HAVAL, SHA, ... It was reported that these hash functions are no longer secure. Our work is focused on the construction of a new hash function based on composition of functions. The construction used the NP-completeness of Three-dimensional contingency tables and the relaxation of the constraint that a hash function should also be a compression function. Une fonction de hachage cryptographique est une procédure déterministe qui compresse un ensemble de données numériques de taille arbitraire en une chaîne de bits de taille fixe. Il existe plusieurs fonctions de hachage : MD5, HAVAL, SHA... Il a été reporté que ces fonctions de hachagene sont pas sécurisées. Notre travail a consisté à la construction d’une nouvelle fonction de hachage basée sur une composition de fonctions. Cette construction utilise la NP-completude des tables de contingence de dimension 3 et une relaxation de la contrainte selon laquelle une fonction de hachage doit être aussi une fonction de compression.

scholarly journals A New Design of Cryptographic Hash Function: Gear

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Abdulaziz M Alkandari ◽  
Khalil Ibrahim Alkandari ◽  
Imad Fakhri Alshaikhli ◽  
Mohammad A. AlAhmad
Keyword(s):  
Hash Function ◽  
Block Cipher ◽  
Hash Functions ◽  
Fixed Size ◽  
Compression Function ◽  
Cryptographic Hash Function ◽  
Mode Of Operation ◽  
Main Components ◽  
Map Data ◽  
And Diffusion

A hash function is any function that can be used to map data of arbitrary sizeto data of fixed size. A hash function usually has two main components: a permutationfunction or compression function and mode of operation. We will propose a new concretenovel design of a permutation based hash functions called Gear in this paper. It is a hashfunction based on block cipher in Davies-Meyer mode. It uses the patched version ofMerkle-Damgård, i.e. the wide pipe construction as its mode of operation. Thus, theintermediate chaining value has at least twice larger length than the output hash. Andthe permutations functions used in Gear are inspired from the SHA-3 finalist Grøestl hashfunction which is originally inspired from Rijndael design (AES). There is a very strongconfusion and diffusion in Gear as a result.

scholarly journals Building a 256-bit hash function on a stronger MD variant

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Harshvardhan Tiwari ◽  
Krishna Asawa
Keyword(s):  
Hash Function ◽  
Design Principle ◽  
Hash Functions ◽  
High Sensitivity ◽  
Differential Attack ◽  
Compression Function ◽  
Single Output ◽  
Generic Attacks ◽  
Cryptographic Techniques ◽  
Cryptographic Hash Functions

AbstractCryptographic hash functions are important cryptographic techniques and are used widely in many cryptographic applications and protocols. All the MD4 design based hash functions such as MD5, SHA-1, RIPEMD-160 and FORK-256 are built on Merkle-Damgård iterative method. Recent differential and generic attacks against these popular hash functions have shown weaknesses of both specific hash functions and their underlying Merkle-Damgård construction. In this paper we propose a hash function follows design principle of NewFORK-256 and based on HAIFA construction. Its compression function takes three inputs and generates a single output of 256-bit length. An extra input to a compression function is a 64-bit counter (number of bits hashed so far). HAIFA construction shows strong resistance against major generic and other cryptanalytic attacks. The security of proposed hash function against generic attacks, differential attack, birthday attack and statistical attack was analyzed in detail. It is shown that the proposed hash function has high sensitivity to an input message and is secure against different cryptanalytic attacks.

scholarly journals Merkle-Damgård Construction Method and Alternatives

2017 ◽  
Vol 41 (2) ◽  
pp. 283-304 ◽  
Author(s):  
Harshvardhan Tiwari
Keyword(s):  
Information Security ◽  
Hash Function ◽  
Hash Functions ◽  
Construction Method ◽  
Security Requirements ◽  
Security Design ◽  
Compression Function ◽  
Cryptographic Hash Function ◽  
Initialization Vector ◽  
Generic Attacks

Cryptographic hash function is an important cryptographic tool in the field of information security. Design of most widely used hash functions such as MD5 and SHA-1 is based on the iterations of compression function by Merkle-Damgård construction method with constant initialization vector. Merkle-Damgård construction showed that the security of hash function depends on the security of the compression function. Several attacks on Merkle-Damgård construction based hash functions motivated researchers to propose different cryptographic constructions to enhance the security of hash functions against the differential and generic attacks. Cryptographic community had been looking for replacements for these weak hash functions and they have proposed new hash functions based on different variants of Merkle-Damgård construction. As a result of an open competition NIST announced Keccak as a SHA-3 standard. This paper provides a review of cryptographic hash function, its security requirements and different design methods of compression function.

scholarly journals Immutability of Distributed Hash Model on Blockchain Node Storage

2021 ◽  
Vol 8 (1) ◽  
pp. 137-143
Author(s):  
Untung Rahardja ◽  
Achmad Nizar Hidayanto ◽  
Ninda Lutfiani ◽  
Dyah Ayu Febiani ◽  
Qurotul Aini
Keyword(s):  
Literature Review ◽  
Hash Function ◽  
Hash Functions ◽  
Research Topic ◽  
Scientific Journals ◽  
Fixed Size ◽  
Mind Mapping ◽  
Block Data

The blockchain system uses hash functions. Hash is used in the blockchain to mark each block of data. Hash function algorithms map a string that is usually hexadecimal of any size to a sequence of fixed-size bits. This journal will discuss the distributed hash model for immutable blockchain node storageThe methodology used in the preparation of this research is mind mapping and literature review, namely the collection of scientific journals, articles and ebooks. Storage of nodes on the blockchain using a distributed hash model. The distributed hash model only stores a portion of the block data at each node, and the block data is taken as a resource. A hash connects each block with the previous on the blockchain, so the entire blockchain transaction cannot be changed or deleted. For further research will expand the research topic regarding storage immutability on the blockchain so that it becomes more complete and detailed.

Data Integrity

2017 ◽  
Author(s):  
Keith M. Martin
Keyword(s):  
Hash Function ◽  
Hash Functions ◽  
Data Integrity ◽  
Message Authentication ◽  
Authenticated Encryption ◽  
Authentication Codes ◽  
Basic Model ◽  
Function Design ◽  
Security Properties ◽  
Different Levels

This chapter discusses cryptographic mechanisms for providing data integrity. We begin by identifying different levels of data integrity that can be provided. We then look in detail at hash functions, explaining the different security properties that they have, as well as presenting several different applications of a hash function. We then look at hash function design and illustrate this by discussing the hash function SHA-3. Next, we discuss message authentication codes (MACs), presenting a basic model and discussing basic properties. We compare two different MAC constructions, CBC-MAC and HMAC. Finally, we consider different ways of using MACs together with encryption. We focus on authenticated encryption modes, and illustrate these by describing Galois Counter mode.

scholarly journals Computational Analysis to Factor Wind into the Design of an Architectural Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hassam Nasarullah Chaudhry ◽  
John Kaiser Calautit ◽  
Ben Richard Hughes
Keyword(s):  
Fluid Dynamics ◽  
Power Generation ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Numerical Data ◽  
Navier Stokes ◽  
Windward Side ◽  
Average Value ◽  
Continuity Equations ◽  
Prevailing Wind Direction

The effect of wind distribution on the architectural domain of the Bahrain Trade Centre was numerically analysed using computational fluid dynamics (CFD). Using the numerical data, the power generation potential of the building-integrated wind turbines was determined in response to the prevailing wind direction. The three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations along with the momentum and continuity equations were solved for obtaining the velocity and pressure field. Simulating a reference wind speed of 6 m/s, the findings from the study quantified an estimate power generation of 6.4 kW indicating a capacity factor of 2.9% for the benchmark model. At the windward side of the building, it was observed that the layers of turbulence intensified in inverse proportion to the height of the building with an average value of 0.45 J/kg. The air velocity was found to gradually increase in direct proportion to the elevation with the turbine located at higher altitude receiving maximum exposure to incoming wind. This work highlighted the potential of using advanced computational fluid dynamics in order to factor wind into the design of any architectural environment.

Graphed equilibrium parameters of channels formed in sediment

1980 ◽  
Vol 7 (1) ◽  
pp. 93-104 ◽  
Author(s):  
A.W. Peterson ◽  
T. Blench
Keyword(s):  
Subject Matter ◽  
Three Dimensional ◽  
Numerical Data ◽  
Reference List ◽  
Laboratory Measurements ◽  
Practical Applications ◽  
Circular Pipes ◽  
The Subject ◽  
Specialized Mathematics ◽  
Major Reference

This paper, for river engineers and their environmental counterparts, presents and explains the origin and potential of four-dimensional charts that smooth most of the world's numerical data obtained from the equilibrium dimensions of sand rivers, gravel rivers, and laboratory flumes. These charts aim to provide a practical service comparable with that provided by factual plots on the comprehensive classic three-dimensional Stanton friction-factor diagram for circular pipes and clean Newtonian fluid. In the river problems, especially, the existence of different phases (whose transitions are not susceptible to formulation), the inadequacies of textbook theories even for simple phases, and the unavoidable imperfections of both field and laboratory measurements combine to prevent responsible design. The remedy is a graphing of total information backed by references from which its reliability and practicability can be assessed.The references have been chosen to contain principal information in the forms of: (i) usable photos, graphs, and tables; (ii) explanations free from specialized mathematics and speculative arguments; and (iii) papers with discussions, authors' replies, and further useful references (since a major reference list would be too long for this paper). Because condensation has had to be extreme the authors will be glad to attempt answers to discussions and questions on the subject matter, its practical applications, and its implications in teaching and research.

Energy and Momentum Eigenspectrum of the Hulthén-screened Cosine Kratzer Potential Using Proper Quantization Rule and SUSYQM Method

2021 ◽  
Author(s):  
Kaushal R Purohit ◽  
Rajendrasinh H PARMAR ◽  
Ajay Kumar Rai
Keyword(s):  
Quantum Mechanics ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Numerical Data ◽  
Time Dependent ◽  
Quantization Rule ◽  
Approximation Approach ◽  
Momentum Spectra ◽  
Energy And Momentum ◽  
Three Dimensional Space

Abstract Using the Qiang-Dong proper quantization rule (PQR) and the supersymmetric quantum mechanics approach, we obtained the eigenspectrum of the energy and momentum for time independent and time dependent Hulthen-screened cosine Kratzer potentials. For the suggested time independent Hulthen-screened cosine Kratzer potential, we solved the Schrodinger equation in D dimensions (HSCKP). The Feinberg-Horodecki equation for time-dependent Hulthen-screened cosine Kratzer potential was also solved (tHSCKP). To address the inverse square term in the time independent and time dependent equations, we employed the Greene-Aldrich approximation approach. We were able to extract time independent and time dependent potentials, as well as their accompanying energy and momentum spectra. In three-dimensional space, we estimated the rotational vibrational (RV) energy spectrum for many homodimers ($H_2, I_2, O_2$) and heterodimers ($MnH, ScN, LiH, HCl$). We also used the recently introduced formula approach to obtain the relevant eigen function. We also calculated momentum spectra for the dimers $MnH$ and $ScN$. The method is compared to prior methodologies for accuracy and validity using numerical data for heterodimer $LiH, HCl$ and homodimer $I_2, O_2,H_2$. The calculated energy and momentum spectra are tabulated and analysed.

scholarly journals Uniform logical cryptanalysis of CubeHash function

2010 ◽  
Vol 23 (3) ◽  
pp. 357-366
Author(s):  
Miodrag Milic ◽  
Vojin Senk
Keyword(s):  
Hash Function ◽  
Hash Functions ◽  
Promising Method ◽  
International Competition ◽  
Great Effort ◽  
Cryptographic Hash Function ◽  
The World ◽  
Cryptographic Hash Functions ◽  
Made In

In this paper we present results of uniform logical cryptanalysis method applied to cryptographic hash function CubeHash. During the last decade, some of the most popular cryptographic hash functions were broken. Therefore, in 2007, National Institute of Standards and Technology (NIST), announced an international competition for a new Hash Standard called SHA-3. Only 14 candidates passed first two selection rounds and CubeHash is one of them. A great effort is made in their analysis and comparison. Uniform logical cryptanalysis presents an interesting method for this purpose. Universal, adjustable to almost any cryptographic hash function, very fast and reliable, it presents a promising method in the world of cryptanalysis.

scholarly journals Comparing the speed of the selected hash and encryption algorithms

2017 ◽  
Vol 4 ◽  
pp. 82-86
Author(s):  
Dawid Górniak ◽  
Piotr Kopniak
Keyword(s):  
Programming Language ◽  
Research Group ◽  
Data Security ◽  
Hash Function ◽  
Hash Functions ◽  
Encryption Algorithm ◽  
Java Programming ◽  
Signature Generation ◽  
Encryption Algorithms ◽  
Valuable Thing

The data is often the most valuable thing that we collect on our computers. Without proper data security with encryption our valuable information may be illegally used by an unauthorised person. The article presents selected encryption methods and hash functions available in Boucy Castle library for Java programming language. The presented analysis applies to measurement of the speed of signature generation and verification. The signatures are for 240 bit encryption algorithms. In case of a hash function, the analysis refers to the speed of such functions. The fastest encryption algorithm and hash function from the research group were AES and SHA1.

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