Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Ograniczanie wyników
Czasopisma help
Lata help
Autorzy help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 55

Liczba wyników na stronie
first rewind previous Strona / 3 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  encryption
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 3 next fast forward last
EN
This document presents a conceptual model of a system for protecting thedata stored in publicly available data storage systems. The main idea was toapply encryption on both the client and server sides that would consequentlyhave a significant impact on data security. The compatibility with existingsystems allows us to deploy the solution fast and at a low cost. The testsconducted on a simplified implementation have confirmed the solution’s validity,and they have shown some possible performance issues as compared to theclassical system (which can be easily bypassed).
EN
Mobile phone may become the protagonist of the new electronic technology. If we compare it with that of other technologies, the infiltration rate of mobile phones in the world is extremely high, both in cities than rural communities of the most of the countries. According to estimates made by the International Telecommunication Union the access to mobile networks is growing much faster than the access to Internet. This emergence has led many companies to allow new activities which were previously running strictly over the Internet to run over the mobile network such as the electronic payment. These circumstances make the security of mobile communication a priority to preserve the authentication, confidentiality and integrity of data sent between subscribers and mobile network. In this paper, we propose a dynamic key generation for the A5 GSM encryption algorithm to enforce the security and protect the transferred data. Our algorithm can be implemented over any GSM generation GSM/3G/4G.
3
Content available remote An Efficient and Secure Cryptosystem for Encrypting Long Messages
100%
EN
Traditionally, due to efficiency considerations, when encrypting long messages using an asymmtric cryptosystem, one needs to use a symmetric cryptosystem in addition. To eliminate this requirement, Hwang, Chang, and Hwang introduced an asymmetric cryptosystem for encrypting long messages. However, they did not give any formal proof of the security of this cryptosystem. In this paper, we propose an improved asymmetric cryptosystem for encrypting long messages, which is both efficient and secure. In the aspect of efficiency, our cryptosystem is about twice as fast as the Hwang-Chang-Hwang cryptosystem. In the aspect of security, besides providing an informal analysis, we rigorously show that computing any part of the plaintext message encrypted using our cryptosystem is as hard as breaking the ElGamal cryptosystem, even if all other parts of the message are already known to the adversary.
EN
The main part of contemporary IT systems are databases. They stores data and provides access to them. When we try to define the concept of database, we do not define how the data is organized in database’s structure. We can distinguish few types of databases: simple (cardindex type and hierarchical) and complex (relational, object, relational and object mixed, stream and temporal). Data security issues in database systems concerns all of the types mentioned above, no matter on the data organization method. The most common database type nowadays is relational. Data security doesn’t mean only to protect them, it is more complex and it contains also authorization mechanisms and user management. Another aspect is something we can call “secure storage” – data encryption and backup policies. When we need to make the database system secure, we need to define how the data is valuable. We need to think about factors which can have influence on the data integrity, we should plan also how to avoid them or how to minimize the risk connected with them. Hacker’s attacks, software bugs or hardware faults can make the data inaccessible or destroyed.
PL
Omówiono podstawowe zagadnienia dotyczące przeciwdziałania zagrożeniom bezpieczeństwa informacyjnego, uwzględnione w standardzie TETRA V+D, takie jak: procedury uwierzytelniania między infrastrukturą sieciową i stacją ruchomą, kryptograficzne zabezpieczenie informacji przekazywanych przez interfejs radiowy w trybie łączności trankingowej i bezpośredniej, bezpieczne zarządzanie kluczami szyfrującymi, zdalne blokowanie i uaktywnianie terminali oraz mechanizm synchronizacji do szyfrowania informacji w relacji "end-to-end". Ponadto przedstawiono aspekty normalizacji interfejsu LI do legalnego podsłuchu.
EN
The paper discusses the main threats to information security in TETRA system and describes the standard countermeasures, which include: authentication between the network infrastructure and mobile equipment, encryption of information transferred over the air interface both in trunked mode and in direct mode, secure management of cipher keys, remote disabling and enabling of terminals, a mechanism to support the synchronization of ,,end-to-end'' encryptions. Additionally, the issues of lawful interception have been presented.
PL
Opracowanie przedstawia najnowsze standardy bezpieczeństwa związane z coraz powszechniej wykorzystywanym językiem XML. Przedstawiona została również krótka charakterystyka wybranych standardów oraz perspektywy ich zastosowań.
EN
The paper presents the latest security standards connected with eXtensible Makup Language (XML), which is increasingly popular in use. The need of introduction the new standards corresponding with the XML document structure is justifield in the article. The paper includes also a short characteristics of the selected standards and the perspectives of their implementation application.
PL
Idea projektowania cyfrowych układów w logice odwracalnej jest wykorzystywana do budowy układów małej mocy. Modelowanie takich układów stało się możliwe dzięki zastosowaniu współczesnych narzędzi symulacyjnych stosowanych do programowania układów FPGA. W niniejszym artykule pokazano wykorzystanie logiki odwracalnej do szyfrowania i przykładową implementację takiego układu. Dla zwiększenia złożoności szyfratora rozbudowano go o programowaną matrycę krosującą zmieniająca kolejność sygnałów wejściowych oraz o układ przekształcania klucza szyfrującego.
EN
A circuit (gate) is called reversible if there is one-to-one correspondence between its inputs and outputs. Research on reversible logic circuits is motivated by advances in quantum computing, nanotechnology and low-power design. Therefore, reversible logic synthesis has been recently intensively studied. The attention is focused mainly on the synthesis of circuits built from the NCT library of gates, i.e. NOT, CNOT and Toffoli gates. Many developers work with design of classical digital devices like registers, adders, processors etc. using reversible circuits. Recently they have also tried to build more complex devices like for example an encryption devices [4, 5, 6, 7], however, only for saving energy. The other point of view, presented in this paper, is to use some features of reversible function. One of them is a big number of functions. For n variables there exist 2n! different function. There are 24 reversible functions for 2 variables, 40320 functions for 3 variables and more than 20x1012 for 4 variables. Synthesis of circuits using 8 variable reversible function is too complicated. We use two cascades using 4 variable reversible function. We consider a 16-gates cascade. Depending on a given reversible function different cascade circuits will be obtained. These circuits correspond to a cryptographic key. Because we assume a 16-gates cascade and there exist 32 various gates we use 80-bit key for a 4-input cascade. Hence, for two cascades a cryptographic key will consist of 160 bits. Modern simulation tools based on FPGAs have enabled modeling of such circuits. In the paper we study application of reversible logic to developing encryption circuits. The results of FPGA-based simulation of a simple encryption circuit implemented built from reversible gates are also presented.
EN
With the increasing uses of internet technologies in daily life, vulnerability of personal data/information is also increasing. Performing secure communication over the channel which is insecure has always been a problem because of speedy development of various technologies. Encryption scheme provides secrecy to data by enabling only authorized user to access it. In the proposed paper, we present an encryption algorithm designed for data security based on bilinear mapping and prove it secure by providing its security theoretical proof against adaptive chosen cipher-text attack. With the help of a lemma, we have shown that no polynomially bounded adversary has non-negligible advantage in the challenging game. We also give the comparative analysis of the proposed scheme in terms of security and performance with Deng et al., 2020 and Jiang et al., 2021 schemes and prove that proposed algorithm is more efficient and secure than others existing in literature against adaptive chosen cipher-text attack.
PL
Wykonywanie przyrostowych kopii zapasowych jest zdecydowanie bardziej efektywne od tworzenia archiwizacji całościowej danych. W przypadku dużych zbiorów różnice w czasie procesu wykonywania kopii i objętości pliku tworzonego materiału widać natychmiast, ponieważ kopio-wane są tyko pliki, w których nastąpiły zmiany, co znacznie zmniejsza ilość miejsca potrzebnego na przechowywanie kolejnych kopii. W artykule tym pokazano przykład wykorzystania systemu do wykonywania kopii zapasowej z kontrolą wersji backupu, która pozwala w przypadku częstych zmian treści w plikach szybko odnaleźć i przywrócić właściwą wersję. Połączenie tego rozwiązania z Cronem umożliwia całkowitą automatyzację procesu.
EN
This article shows an example of use of the system to perform a backup of the backup version control, which allows for frequent changes to the content in the files quickly locate and restore the correct version. Combining this approach with Cron allows to completely automate the process.
PL
Układy FPGA dobrze nadają się do modelowania układów odwracalnych, których implementacje sprzętowe są dopiero w stadium opracowywania. Układy odwracalne umożliwiają prostą realizację szyfratorów i deszyfratorów. W artykule rozpatrzono działanie dwóch szesnasto-bramkowych kaskad zbudowanych z cztero-wejściowych bramek odwracalnych NCT, aby uzyskać bajtowo zorientowany szyfrator. Zbiór bramek NCT o co najwyżej czterech wejściach zawiera 32 bramki, więc dla skonfigurowania jednej bramki potrzeba 5 bitów. Zatem kaskada może być określona przez 80-bitowe słowo, co dla dwóch kaskad daje 160-bitowy klucz. Po każdym wejściowym bajcie obie kaskady są rekonfigurowane za pomocą odpowiedniego przesuwania 80-bitowych słów. Sposoby przesuwania są określane przez dodatkowe bity klucza pomocniczego.
EN
FPGAs can be applied to modeling of reversible circuits because their practical realization is still under development. This technique enables implementing substitution ciphers. We try to build a byte-oriented stream cipher. Such a cipher uses two four-input and four-output cascades. Each of the cascades contains 16 reversible NCT gates. Because there exist 32 different NCT gates having at most four inputs we use 80 bits (16×5 bits) to determine one cascade so for two cascades 160 bits are needed. These bits are called the base key and are stored in the memory of a cipher. At the beginning of encryption the key is loaded to a circular shift register. After each input byte (a clock period) the contents of the shift register is shifted by a specified number of bits. The number of bits by which the register contents is shifted constitutes the second part of the cipher key. The shifting process causes changes in cascades after each input byte. If shifting the key is the same during both encryption and decryption, then the cipher will work correctly. In the paper, we present some methods of key shifting. If the register contents is shifted by 5 bits, then each gate is replaced by its predecessor (the first gate is replaced by the last one). The results of different shifting modes are presented showing that in all cases correct encryption/decryption is performed. For modeling and simulation of synthesis we used test-bench software ActiveHDL v 8.2 from ALDEC.
12
Content available remote Survey on cloud computing vulnerability and cyber attacks: a defensive approach
75%
EN
Cyber attacks against cloud computing discourage users to migrate to cloud computing. Cloud computing currently has weaknesses in terms of securing data. Unprotected data and weak storage security are potential threats to cloud computing. There are security risks and they should be considered carefully before enterprises migrate to cloud computing. Specifying cloud computing vulnerabilities and defining cyber attacks against infrastructure of the Cloud are the targets of this research. Mitigation of the non-technical problems may decrease the security problems. However, cryptographies, distributed denial of service and flooding attacks damage the servers and services. In this research, my aim is to demonstrate cloud computing vulnerability and the threats against data and storage. Once the cloud security problems are defined, the next step is to look for a solution. Using forensic methods to inspect intrusion attempts, implementing an online forensic workstation monitoring the login details of cloud authentication server, providing evidence of cyber crime are recommended.
13
Content available Dedicated Digital Hardware for DVB-CSA Encryption
75%
EN
DVB-CSA (Digital Video Broadcast - Common Scrambling Algorithm) is encryption method commonly used to protect the paid channels of digital television. The paper presents a study of its implementation in specialized digital hardware. The algorithm was successfully converted to logic architecture, coded in hardware description language (VHDL), verified and synthesized for programmable logic device (FPGA). For Xlinx Spartan 3 implementation, the expected throughput may be estimated to 100 Mbps in pipelined mode.
PL
Rozwiązania serwerowe oparte na systemach linuxowych pozwalają zablokować zdalny dostęp do swoich zasobów poprzez wpisanie adresu IP do pliku /etc/hosts.deny. Jest to skuteczna metoda pozwalająca na blokadę szczególnie uciążliwych klientów, których zamiary są bliżej nieokreślone. W tym artykule przedstawiono przykład zamiany pozyskanych adresów IP na powiązane z nimi położenie geograficzne, celem uzyskania rozkładu geograficznego potencjalnego zagrożenia.
EN
Server solutions based on systems Linux boxes allow to block remote access to their resources by typing the IP address into the /etc/hosts.deny file. This is an effective method of blocking a particularly onerous customers whose intentions are vague. This article is an example of the conversion of obtained IP addresses to related geographical locations to obtain the geographical distribution of potential danger
PL
Referat przedstawia metodykę projektowania zabezpieczeń teleinformatycznych w oparciu o normy międzynarodowe "Wspólne Kryteria do Oceny Zabezpieczeń Teleinformatycznych" (ISO/IEC 15408). Opisane zostały kolejne etapy projektowania Profilu oraz Zadania Zabezpieczeń. Zaprezentowany został również przykład Zadania Zabezpieczeń dla aplikacji do szyfrowania i podpisywania dokumentów elektronicznych. SecOffice
EN
The paper presents designing methodology of IT security based on the international standard Common Criteria for IT Security Evaluation (ISO/IEC 15408). The designing steps for the Protection Profile and Security Target were described. The paper presents an example of SecOffice' s Security Target - the application used to digital signature and encryption of electronic documents.
PL
Przedstawiono zasadnicze elementy standardowych podsystemów bezpieczeństwa (802.11, 802.11i) stosowanych w bezprzewodowych sieciach lokalnych. Dla standardu 802.11, zastosowanych protokołów i algorytmów, scharakteryzowano podstawowe zagrożenia wynikające zarówno ze świadomie przyjętych założeń, jak i błędów wynikających z nieumiejętnego wykorzystania prymitywów kryptograficznych do budowy całego systemu.
EN
The paper presents basic elements of standard security subsystems (802.11, 802.11i) used in wireless local area networks. In addition to implemented protocols and algorithms in 802.11, threats resulted from both design principles and wrong application of cryptographic primitives in overall system construction were characterised.
17
75%
PL
Artykuł dotyczy istotnego problemu, związanego z ograniczeniem odległosci na jaką może zostać przesłany klucz krytograficzny, przy zastosowaniu do tego celu kwantowych metod uzgadniania klucza szyfrującego. Przedstawiono do tego celu kwantowych metod fgrię w nim model uzgadniania klucza pozwalający przekroczyc granicę wyznaczoną przez dwa komunikujące się urządzenia kwantowe.
EN
The paper consists of four parts. First, definitions of supply chain and supply chain management are accommodated. Second, VMI (Vendor Managed Inventory) is explained. Third, pharmaceutical producer's supply chain, and implemented SCM model is described. Finally, effectiveness assessment of proposed VMI model is conducted.
18
75%
EN
We propose and study a new technique for securing fibre data communication. The paper presents a method for optical encryption of information transmitted with a traditional fibre link. The encryption method uses a spatial light modulator which converts light pulses representing original data into pseudo-random patterns. A linear combination of light pulses with pseudo-random patterns provides a required encryption performance. The main element of the encryptor is the spatial light modulator which comprises a matrix of cells selectively transmitting or blocking the light beam depending on the pseudo-random configuration of cells. The encrypted information is transmitted through the optical fibre. The decryption process relies on a computational solving of linear program or greedy pursuit. We present a brief description of the method, theoretical analysis and results of numerical simulation. A physical model concept of the method is also presented.
PL
W artykule omawiamy podstawy proponowanego krypto-systemu RSA z kluczem jednorazowym (OTP). Głównym pomysłem na uzyskanie bezwarunkowego bezpieczeństwa jest przekazanie modułu szyfrowani n=pq tylko uprawnionym użytkownikom a upublicznianie wartości Δn umożliwiającej wygenerowanie właściwego klucza szyfrowania n’=p’q’ tylko uprawnionym. Zamiast udostępnienia wartości Δn można udostępnić informację dotyczącą różnicy w konfiguracji układu zdolnego do rekonfiguracji przystosowującej system do nowych obliczeń. Tak realizowany krypto-system łagodzi problemu dystrybucji kluczy i zapewnia bezpieczeństwo bezwarunkowe, oparte na dużej różnorodności możliwych komunikatów wygenerowanych kluczami spełniającymi reguły OTP.
EN
In this paper we address the basis of a proposed one time pad (OTP) RSA cryptosystem. The main idea is to provide fundamental values of n = pq only authorized users but keep away from the other, then share the following values Δ n to designate n' = p'q' authorized users as a component of the public key. Instead of public sharing the value of Δ n, is possible to making a large size difference configurations stream and reconfiguring system. Such a cryptosystem is unconditionally safe because it is based on a many differentia and possible messages generated by different secret keys generated in accordance with the OTP principles.
20
Content available Combining message encryption and authentication
75%
EN
The first part of the paper explains the need for combining message encryption and authentication. We begin with the example to emphasize the fact that privacy‡ does not imply authenticity. Then we prove, one needs both privacy and authenticity, even if one's aim is just getting privacy. In the second part we present an overview of different methods for providing authenticated encryption (AE) i.e. generic compositions, single-pass modes and two-pass combined modes. We analyze what are the advantages and disadvantages of different AE constructions. In the third part of the paper we focus on nonce§ based authenticated encryption modes. Our motivation is the wish to know the methodology of designing authenticated encryption mode of operation. We take into consideration a few most important properties, e.g. parallelizability, memory requirements and pre-processing capability. We analyze possibilities of choice of underlying encryption and authentication components and their order in a message we also try to answer. What does single-key mode really mean? Finally we mention the importance of provable security theory in the security of authenticated encryption modes.
first rewind previous Strona / 3 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.