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symmetric PARAREAL algorithms FOR HAMILTONIAN SYSTEMS

ESAIM-MATHEMATICAL MODELLING AND NUMERICAL ANALYSIS-MODELISATION MATHEMATIQUE ET ANALYSE NUMERIQUE 2013年第3期47卷 717-742页

作者： Dai, Xiaoying Le Bris, Claude Legoll, Frederic Maday, Yvon Chinese Acad Sci Acad Math & Syst Sci Inst Computat Math & Sci Engn Comp LSEC Beijing 100190 Peoples R China Ecole Natl Ponts & Chaussees F-77455 Marne La Vallee 2 France INRIA Rocquencourt MICMAC Team Project F-78153 Le Chesnay France UPMC Univ Paris 06 Lab JL Lions UMR 7598 F-75252 Paris 05 France Brown Univ Div Appl Math Providence RI 02912 USA

The parareal in time algorithm allows for efficient parallel numerical simulations of time-dependent problems. It is based on a decomposition of the time interval into subintervals, and on a predictor-corrector strategy, where the propagations over each subinterval for the corrector stage are concurrently performed on the different processors that are available. In this article, we are concerned with the long time integration of Hamiltonian systems. Geometric, structure-preserving integrators are preferably employed for such systems because they show interesting numerical properties, in particular excellent preservation of the total energy of the system. Using a symmetrization procedure and/or a ( possibly also symmetric) projection step, we introduce here several variants of the original plain parareal in time algorithm [L. Baffico, et al. Phys. Rev. E 66 ( 2002) 057701;G. Bal and Y. Maday, A parareal time discretization for nonlinear PDE's with application to the pricing of an American put, in Recent developments in domain decomposition methods, Lect. Notes Comput. Sci. Eng. 23 ( 2002) 189-202;J.-L. Lions, Y. Maday and G. Turinici, C. R. Acad. Sci. Paris, Serie I 332 ( 2001) 661-668.] that are better adapted to the Hamiltonian context. These variants are compatible with the geometric structure of the exact dynamics, and are easy to implement. Numerical tests on several model systems illustrate the remarkable properties of the proposed parareal integrators over long integration times. Some formal elements of understanding are also provided.

关键词： Parallel integrators Hamiltonian dynamics long-time integration symmetric algorithms symmetric projection geometric integration

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Energy-Aware Framework for Assessing Cryptographic algorithms in Wireless Sensor Networks

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SN Computer Science 2025年第4期6卷 1-17页

作者： Pooja Shalu Saini, Neha Baghela, Vishwadeepak Singh Khan, Mohd Anas School of Computer Science Engineering and Technology Bennett University Uttar Pradesh Greater Noida India Manav Rachna University Faridabad Haryana Faridabad India Government College Chhachhrauli Haryana Yamuna Nagar India SCSE Galgotias University Uttar Pradesh Greater Noida India Department of Computer Engineering Jamia Millia Islamia Delhi India

Wireless sensor networks have found applications in several areas such as agriculture, healthcare, weather forecasting, and the Internet of Things. Due to their extensive use WSNs are susceptible to several significant network threats. Therefore, they necessitate the implementation of advanced security measures. An issue of significant concern is the possible violation of user privacy resulting from the transmission of data. The rapid increase in online transactions and the vast volume of data generated on a daily basis have elevated information security to an important concern in the present era of the internet. Cryptography serves as a durable remedy to these issues by bolstering the confidentiality of data transmitted across the internet. This study analysed many characteristics, such as the total execution time, memory needs, number of packets sent to the base station, number of dead nodes, remaining energy after transmission, and the use of RSA algorithm and Elliptic Curve Cryptography. The simulation is executed in MATLAB utilising pre-defined parameters and constants. A WSN observation scenario was demonstrated with a fixed number of rounds (200) and varying numbers of nodes (5, 10, 15, and 20). The researchers computed the average ratio of packets transferred to the base station, inoperative nodes, and leftover energy after transmission. The upper limit for the number of packets that can be successfully transmitted to the base station using AES is 55%. This is subject to the condition that at least 40% of the nodes are inactive and a maximum of 45% of the nodes have residual energy. The primary achievement of the current work is the identification of the most effective energy-efficient encryption algorithm, as previous research has not focused extensively on this particular characteristic. Based on the simulation results, AES outperforms RSA and Elliptic Curve Cryptography in terms of packet transmission, inactive nodes, and energy conservation. © The Author

关键词： AES Asymmetric algorithm Cryptography ECC Energy left RSA symmetric algorithms

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Cybersecurity Challenges Associated With the Internet of Things in a Post-Quantum World

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IEEE ACCESS 2020年 8卷 157356-157381页

作者： Althobaiti, Ohood Saud Dohler, Mischa Kings Coll London Dept Engn London WC2R 2LS England

The Internet of Things (IoT) is an emerging networking paradigm connecting billions of devices securely to the Internet. Another emerging paradigm is quantum computing which - while opening new compute opportunities - was shown to jeopardise most cybersecurity protocols. In this study, we discuss techniques able to provide security in a post-quantum IoT. Specifically, we examine how the third-generation partnership project (3GPP) IoT security solutions fair in a post-quantum environment. Also, we analyse the security features of fifth-generation (5G) networks, propose improvements and discuss the manner in which a quantum computer can compromise security. Our results prove the existence of multiple vulnerabilities in the current IoT architecture and implementations. With advances in quantum computing having rendered the current security algorithms unsafe, more advanced techniques should be established to mitigate such risks. To this end, we present promising lattice-driven cryptographic techniques which we prove quantum resistance.

关键词： Quantum computing Ciphers Encryption Computer security 3GPP Security IoT LTE-M NB-IoT 3GPP 5G networks quantum cryptography symmetric algorithms asymmetric algorithms lattice-based cryptography

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symmetric rendezvous with advice: How to rendezvous in a disk

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JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING 2019年 134卷 13-24页

作者： Georgiou, Konstantinos Griffiths, Jay Yakubov, Yuval Ryerson Univ Dept Math 350 Victoria St Toronto ON M5B 2K3 Canada

In the classic symmetric Rendezvous problem on a Line (SR-LINE), two robots at known distance 2 but unknown direction execute the same randomized algorithm trying to minimize the expected rendezvous time. A long standing conjecture is that the best possible rendezvous time is 4.25 with known upper and lower bounds being very close to that value. We introduce and study a geometric variation of SR-LINE that we call symmetric Rendezvous in a Disk (SR-DISK) where two robots at distance 2 have a common reference point at distance rho. We show that even when rho is not too small, the two robots can meet in expected time that is less than 4.25. Part of our contribution is that we demonstrate how to adjust known, even simple and provably non-optimal, algorithms for SR-LINE, effectively improving their performance in the presence of a reference point. Special to our algorithms for SR-DISK is that, unlike in SR-LINE, for every fixed rho the worst case distance traveled in our algorithms is finite. In particular, we show that the worst case distance of our algorithms is O (rho(2)), while we also explore average-worst case tradeoffs, concluding that one may be efficient both with respect to average and worst case, with only a minor compromise on the optimal termination time. (C) 2019 Elsevier Inc. All rights reserved.

关键词： Rendezvous problem symmetric algorithms Disk Average case analysis Worst case analysis

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Introducing SmartCards to remote authenticate passwords using public key encryption

Introducing SmartCards to remote authenticate passwords usin...

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IEEE/Sarnoff Symposium on Advances in Wired and Wireless Communication

作者： Badra, M Urien, P Ecole Natl Super Telecommun Bretagne F-75013 Paris France

ISBN: (纸本)0780382196

Password authentication is one of the most local and remote authentication methods. This can be done by sharing a password between the peers. At the operating system server, the passwords file must be protected against any attack. Actually, almost all operating systems protect this file using one way functions like MD5 or symmetric algorithms such as DES. The UNIX password protection scheme is an example of a security mechanism making use of one way functions. The problem here is that a directed dictionary attack can almost always succeed to break the password using a simple work station. In this paper, we propose a new approach based on asymmetric encryption algorithms and the SmartCards technology to allow the passwords file protection and to prohibit middlemen from having the password during its transit over the connection.

关键词： public key cryptography telecommunication security message authentication smart cards smartcards password authentication public key encryption operating system server passwords file protection one way functions symmetric algorithms DES Unix password protection scheme security mechanism directed dictionary attack asymmetric encryption algorithms Health Smart Cards Public key encryption security mechanism Passwords public key cryptography telecommunication security message authentication one-way function Operating systems one way

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A Review of Cloud Security Based on Cryptographic Mechanisms 4

A Review of Cloud Security Based on Cryptographic Mechanisms

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International Symposium on Biometrics and Security Technologies (ISBAST)

作者： Abd, Sura Khalil Al-Haddad, S. A. R. Hashim, Fazirulhisyam Abdullah, Azizol Univ Putra Malaysia Comp & Commun Engn Serdang Malaysia Univ Putra Malaysia Comp Sci & Informat Technol Serdang Malaysia

ISBN: (纸本)9781479964444

Recently, computer users can maintain their data and applications on the Internet and in the central remote server by using a technology called cloud computing. It is a kind of technology that allows users to access their personal files from any device provided with Internet services such technology offers even more applications to be utilized without installation. This paper presents a review of basic security challenges consisting of traditional security issues. It also discusses the additional challenges that take place as a result of using cloud computing model by providers and users of cloud systems. Furthermore, solutions suggested by some researchers are presented with a focus on cryptographic techniques that approve secure cloud storage.

关键词： Cloud Computing Cryptographic Techniques Multicast symmetric algorithms

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Comparison of RC6, Modified RC6 & Enhancement of RC6 2

Comparison of RC6, Modified RC6 & Enhancement of RC6

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International Conference on Advances in Computer Engineering and Applications (ICACEA)

作者： Aggarwal, Kirti IMSEC Dept Comp Sci & Engn Ghaziabad India

ISBN: (纸本)9781467369114

In this paper we are going to compare the symmetric Block cipher RC6 with the two more versions of RC6. Modified RC6 and Enhanced RC6 provide some improvements of RC6, which is latest version of AES. The basic difference between the three algorithms is that RC6 works on block size of 128 bits, Enhancement of RC6 (RC6e) works on block size of 256 bits and Modified RC6 (MRC6) works on block size of 512 bits. The basic operations used in the three algorithms are same. All the three algorithms consist of three parts encryption, decryption and key expansion. In this paper we are going to compare these algorithms on the basis of encryption and decryption time on the basis of different file size and file types.

关键词： RC6 RC6e MRC6 symmetric algorithms Encryption Decryption Block Cipher AES

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CRYPTOGRAPHIC ALGORITHM TEST AND PERFORMANCE ANALYSIS IN LOW POWER CAPABILITIES

CRYPTOGRAPHIC ALGORITHM TEST AND PERFORMANCE ANALYSIS IN LOW...

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International Conference on Artificial Intelligence and Data Processing (IDAP)

作者： Tacettin, Bengu Guven, Ebu Yusuf Yagci, Mehmet Yavuz Aydin, Muhammed Ali Istanbul Univ Cerrahpasa Bilgisayar Muhendisligi Istanbul Turkey

ISBN: (纸本)9781538668788

Sensor devices, RFID tags, wireless sensor networks, Internet of Things and embedded systems, which have increasing usage areas in human life, connect objects internally and maintain continuous communication with each other in a controlled manner with the application fields developed with technological investments and incentives. Seizing of data by unauthorized persons constitutes a serious weakness in terms of security. Cryptography algorithms are also used to create a secure communication by avoiding weaknesses. However, limited resources, such as memory, RAM, battery, etc., affect performance, limit the cryptography algorithms to be applied. This article also examines lightweight encryption algorithms developed for use in restricted sources. Examples of articles that include performance tests and analysis of lightweight algorithms in the literature are included. Cryptographic message transmission is performed by using lightweight block encryption algorithms between two objects with different hardware properties and performance analysis is performed.

关键词： Lightweight cryptography symmetric algorithms Asymmetric algorithms Constrained devices Block ciphers Internet-of-thing RFID Wireless sensor network

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Výkonnostní testy kryptografických algoritmů

Výkonnostní testy kryptografických algoritmů

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作者： Pospíšil, Karel Brno University of Technology

Bakalářské práce se zabývá rozborem jednotlivých kryptografických algoritmů, které se využívají při zabezpečování komunikace. První část je věnov&... 详细信息

Bakalářské práce se zabývá rozborem jednotlivých kryptografických algoritmů, které se využívají při zabezpečování komunikace. První část je věnována symetrickým kryptografickým algoritmům, asymetrickým kryptografickým algoritmům a hashovacím funkcím. Druhá část se zabývá bezpečností, stupni utajení a útoky, které se využívají při napadání kryptografických algoritmů a hashovacích funkcí. Třetí část se věnuje testování vybraného algoritmu RC4 a hashovací funkce MD5 za pomocí programu CrypTool. V závěrečné části jsou uvedeny a zhodnoceny výsledky testů algoritmu RC4 a hashovací funkce MD5.

关键词： Symetrický algoritmus asymetrický algoritmus hashovací funkce bezpečnost útok kryptografie kryptoanalýza šifrovaní dešifrování. symmetric algorithms asymmetric algorithms hash function security attack cryptography cryptanalysis encryption

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Energy efficient distributed lightweight authentication and encryption technique for IoT security

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2022年第2期35卷 e4198-e4198页

作者： Sudhakaran, Pradeep Malathy, C. SRM Inst Sci & Technol Dept Comp Sci & Engn Kattankulathur 603203 India

Internet of Things (IoT) is an intelligent technology and service that mutually communicates information between human and devices or between Internet-based devices. In IoT security, the authentication should be distributed and lightweight. Token generation should be based on the trust worthiness of the devices, and it needs to ensure fast authentication and authorization. In this paper, we propose an Energy Efficient Distributed Lightweight Authentication and Encryption (EEDLAE) technique for IoT security. In our proposed technique, the receiver generates the token for each sender. The token expiration time is determined based on the trust value of each sender, and sleep period of the receiver radio is determined based on its remaining energy. For encryption, Counter with Cipher Block Chaining-Message Authentication Code (CCM) is applied. Experimental results show that EEDLAE technique can hold out against affected packets, higher resilience against node capture, increased throughput, and residual energy, compared with the existing technique.

关键词： authentication cipher block chaining IoT security symmetric algorithms trust estimation

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