scholarly journals Dekripsi Algoritma Rivest-Shamir-Adleman Dengan Komputasi Paralel Menggunakan Message Parsing Interface

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Evangs Mailoa

Abstract. Rivest-Shamir-Adleman algorithm is a cryptographic algorithm that is difficult to be dismantled. This is due to the difficulty of factoring large numbers modulus n into prime factors (p and q). The process of modulus factoring requires a very long time if solved by serial computation. Brute Force Attack method is used to find large prime numbers p and q with parallel computation. Applications for the factorization of prime numbers p and q are developed using Visual C ++ and Message Passing Interface, while the decryption process developed with Java. The results show a parallel computing process faster than a serial for factoring very large numbers n, and very slow if the n is too small.Keywords: Rivest-Shamir-Adleman Algorithm, Brute Force Attack, Message Passing Interface. Abstrak. Algoritma Rivest-Shamir-Adleman merupakan salah satu algoritma kriptografi yang sukar untuk dibongkar. Hal ini dikarenakan sulitnya memfaktorkan bilangan modulus n yang besar menjadi faktor-faktor prima (nilai p dan q). Proses untuk faktorisasi modulus n membutuhkan waktu yang sangat lama apabila diselesaikan dengan komputasi serial. Penelitian ini menggunakan metode Brute Force Attack untuk menemukan bilangan prima p dan q yang sangat besar yang dikerjakan secara paralel. Aplikasi untuk faktorisasi bilangan prima p dan q dikembangkan menggunakan Visual C++ memanfaatkan Message Passing Interface, sedangkan aplikasi proses dekripsi dengan Java. Hasil ujicoba menunjukkan proses komputasi paralel lebih cepat dibandingkan secara serial untuk memfaktorkan bilangan n yang sangat besar, dan menjadi sangat lambat apabila bilangan n terlalu kecil. Kata kunci: Algoritma Rivest-Shamir-Adleman, Brute Force Attack, Message Passing Interface.

2021 ◽  
Vol 297 ◽  
pp. 01046
Author(s):  
Zhour Oumazouz ◽  
Driss Karim

The main objective of the study conducted in this article is to introduce a new algorithm of encryption and decryption of a sensitive message after transforming it into a binary message. Our proposed encryption algorithm is based on the study of a particular graph constructed algebraically from the quadratic residues. We have exploited the Paley graph to introduce an abstract way of encryption of such message bit according to the other message bits by the intermidiate study of the neighborhood of a graph vertex. The strong regularity of the Paley graphs and the unknown behavior of the quadratic residues will play a very important role in the cryptanalysis part which allows to say that the brute force attack remains for the moment the only way to obtain the set of possible messages.


Author(s):  
Ning Yang ◽  
Shiaaulir Wang ◽  
Paul Schonfeld

A Parallel Genetic Algorithm (PGA) is used for a simulation-based optimization of waterway project schedules. This PGA is designed to distribute a Genetic Algorithm application over multiple processors in order to speed up the solution search procedure for a very large combinational problem. The proposed PGA is based on a global parallel model, which is also called a master-slave model. A Message-Passing Interface (MPI) is used in developing the parallel computing program. A case study is presented, whose results show how the adaption of a simulation-based optimization algorithm to parallel computing can greatly reduce computation time. Additional techniques which are found to further improve the PGA performance include: (1) choosing an appropriate task distribution method, (2) distributing simulation replications instead of different solutions, (3) avoiding the simulation of duplicate solutions, (4) avoiding running multiple simulations simultaneously in shared-memory processors, and (5) avoiding using multiple processors which belong to different clusters (physical sub-networks).


Author(s):  
Yu-Cheng Chou ◽  
Harry H. Cheng

Message Passing Interface (MPI) is a standardized library specification designed for message-passing parallel programming on large-scale distributed systems. A number of MPI libraries have been implemented to allow users to develop portable programs using the scientific programming languages, Fortran, C and C++. Ch is an embeddable C/C++ interpreter that provides an interpretive environment for C/C++ based scripts and programs. Combining Ch with any MPI C/C++ library provides the functionality for rapid development of MPI C/C++ programs without compilation. In this article, the method of interfacing Ch scripts with MPI C implementations is introduced by using the MPICH2 C library as an example. The MPICH2-based Ch MPI package provides users with the ability to interpretively run MPI C program based on the MPICH2 C library. Running MPI programs through the MPICH2-based Ch MPI package across heterogeneous platforms consisting of Linux and Windows machines is illustrated. Comparisons for the bandwidth, latency, and parallel computation speedup between C MPI, Ch MPI, and MPI for Python in an Ethernet-based environment comprising identical Linux machines are presented. A Web-based example is given to demonstrate the use of Ch and MPICH2 in C based CGI scripting to facilitate the development of Web-based applications for parallel computing.


2012 ◽  
Vol 433-440 ◽  
pp. 2892-2898
Author(s):  
Guang Lei Fei ◽  
Jian Guo Ning ◽  
Tian Bao Ma

Parallel computing has been applied in many fields, and the parallel computing platform system, PC cluster based on MPI (Message Passing Interface) library under Linux operating system is a cost-effectiveness approach to parallel compute. In this paper, the key algorithm of parallel program of explosion and impact is presented. The techniques of solving data dependence and realizing communication between subdomain are proposed. From the test of program, the portability of MMIC-3D parallel program is satisfied, and compared with the single computer, PC cluster can improve the calculation speed and enlarge the scale greatly.


1997 ◽  
Vol 40 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Jehoshua Bruck ◽  
Danny Dolev ◽  
Ching-Tien Ho ◽  
Marcel-Cătălin Roşu ◽  
Ray Strong

Author(s):  
Peng Wen ◽  
Wei Qiu

This paper presents the further development of numerical simulation method to solve 3-D highly non-linear slamming problems using parallel computing algorithms. The water entry problems are treated as multi-phase problems (solid, water and air) and governed by the Navier-Stokes (N-S) equations. They are solved by the three-dimensional constrained interpolation profile (CIP) method. The interfaces between different phases are captured using density functions. In the computation, the 3-D CIP method is employed for the advection phase of the N-S equations and a pressure-based algorithm is applied for the non-advection phase. The bi-conjugate gradient stabilized method (BiCGSTAB) is utilized to solve the linear equation systems. A Message Passing Interface (MPI) parallel computing scheme was implemented in the computations. For the parallel computations, the three-dimensional Cartesian decomposition of the computational domain was used. The speed-up performance of various decomposition schemes were studied. Validation studies were carried out for the water entry of a 3-D wedge and a 3-D ship section with prescribed velocities. The computed slamming force, pressure distribution and free-surface elevations are compared with experimental results and numerical results by other methods.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1548
Author(s):  
Jung Min Ahn ◽  
Hongtae Kim ◽  
Jae Gab Cho ◽  
Taegu Kang ◽  
Yong-seok Kim ◽  
...  

Process-based numerical models developed to perform hydraulic/hydrologic/water quality analysis of watersheds and rivers have become highly sophisticated, with a corresponding increase in their computation time. However, for incidents such as water pollution, rapid analysis and decision-making are critical. This paper proposes an optimized parallelization scheme to reduce the computation time of the Environmental Fluid Dynamics Code-National Institute of Environmental Research (EFDC-NIER) model, which has been continuously developed for water pollution or algal bloom prediction in rivers. An existing source code and a parallel computational code with open multi-processing (OpenMP) and a message passing interface (MPI) were optimized, and their computation times compared. Subsequently, the simulation results for the existing EFDC model and the model with the parallel computation code were compared. Furthermore, the optimal parallel combination for hybrid parallel computation was evaluated by comparing the simulation time based on the number of cores and threads. When code parallelization was applied, the performance improved by a factor of approximately five compared to the existing source code. Thus, if the parallel computational source code applied in this study is used, urgent decision-making will be easier for events such as water pollution incidents.


Author(s):  
Peng Wen ◽  
Wei Qiu

A constrained interpolation profile (CIP) method has been developed to solve 2-D water entry problems. This paper presents the further development of the numerical method using staggered grids and a parallel computing algorithm. In this work, the multi-phase slamming problems, governed by the Navier-Stokes (N-S) equations, are solved by a CIP-based finite difference method. The interfaces between different phases (solid, water and air) are captured using density functions. A parallel computing algorithm based on the Message Passing Interface (MPI) method and the domain decomposition scheme was implemented to speed up the computations. The effect of decomposition scheme on the solution and the speed-up were studied. Validation studies were carried out for the water entry of various 2-D wedges and a ship section. The predicted slamming force, pressure distribution and free surface elevation are compared with experimental results and other numerical results.


2012 ◽  
Vol 532-533 ◽  
pp. 1080-1084 ◽  
Author(s):  
Zhi Cai Shi ◽  
Can Qun Yang ◽  
Qiang Wu

MD5 Crypt is a cryptographic algorithm used commonly in UNIX system for authentication. Thanks to the additional randomization of the salt and complexity of the scheme, it makes the traditional password cracking techniques invalid on common computing systems so that the security of the system is guaranteed. As a result of the thriving of petaflops heterogeneous supercomputer system in recent decades, the security of MD5 Crypt is facing a threat of brute-force attack again. However, the complexity of heterogeneous programming and the sophistication of large-scale parallelism still hamper the password recovering. In this paper, we implemented brute-force attack of MD5 Crypt on Tianhe-1A,the world’s fastest supercomputer, by organizing the assignment between CPU and GPU reasonably and making several optimizations according to MD5 Crypt for GPU. Based on the experimental results, our algorithm achieves a great scalability. It checked more than 1.8 billion passwords in a second on the full system. Thus it issues a new challenge to the security of MD5 crypt for authentication.


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