876 resultados para còpia de seguretat
Resumo:
In the wake of the success of Peer-to-Peer (P2P) networking, security has arisen as one of its main concerns, becoming a key issue when evaluating a P2P system. Unfortunately, some systems' design focus targeted issues such as scalabil-ity or overall performance, but not security. As a result, security mechanisms must be provided at a later stage, after the system has already been designed and partially (or even fully) implemented, which may prove a cumbersome proposition. This work exposes how a security layer was provided under such circumstances for a specic Java based P2P framework: JXTA-Overlay.
Resumo:
The JXTA-Overlay project is an effort to use JXTA technologyto provide a generic set of functionalities that can be used by developers to deploy P2P applications. Since its design mainly focuses on issues such as scalability or overall performance, it does not take security into account. However, as P2P applications have evolved to fulfill more complex scenarios, security has become a very important aspect to take into account when evaluating a P2P framework. This work proposes a security extension specifically suited to JXTA-Overlay¿s idiosyncrasies, providing an acceptable solution to some of its current shortcomings.
Resumo:
Sensor networks have many applications in monitoring and controlling of environmental properties such as sound, acceleration, vibration and temperature. Due to limitedresources in computation capability, memory and energy, they are vulnerable to many kinds of attacks. The ZigBee specification based on the 802.15.4 standard, defines a set of layers specifically suited to sensor networks. These layers support secure messaging using symmetric cryptographic. This paper presents two different ways for grabbing the cryptographic key in ZigBee: remote attack and physical attack. It also surveys and categorizes some additional attacks which can be performed on ZigBee networks: eavesdropping, spoofing, replay and DoS attacks at different layers. From this analysis, it is shown that some vulnerabilities still in the existing security schema in ZigBee technology.
Resumo:
The design of an efficient collaborative multirobot framework that ensures the autonomy and the individualrequirements of the involved robots is a very challenging task. This requires designing an efficient platform for inter-robot communication. P2P is a good approach to achieve this goal. P2P aims at making the communication ubiquitous thereby crossing the communication boundary and has many attractive features to use it as a platform for collaborative multi-robot environments. In this work, we present the JXTA Overlay P2P system and its application for robot control. Since JXTAOverlay is able to overcome Firewalls, Routers and NATs, it is possible to control end-devices in a WAN without changing the network security policy. We used JXTA-Overlay for the control of robot motors. We evaluated the proposed system by many experiments and have shown that the proposed system has a good performance and can be used successfully for the control of robot.
Resumo:
La informació biomètrica s'ha convertit en una tecnologia complementària a la criptografia que permet administrar còmodament les dades criptogràfiques. Són útils dues necessitats importants: en primer lloc, posar aquestes dades sempre a mà i, a més, fent fàcilment identificable el seu legítim propietari. En aquest article es proposa un sistema que integra la signatura biomètrica de reconeixement facial amb un esquema de signatura basat en la identitat, de manera que la cara de l'usuari esdevé la seva clau pública i la ID del sistema. D'aquesta manera, altres usuaris poden verificar els missatges utilitzant fotos del remitent, proporcionant un intercanvi raonable entre la seguretat del sistema i la usabilitat, així com una manera molt més senzilla d'autenticar claus públiques i processos de distribució.
Resumo:
En l'actualitat, la maduresa del camp de la investigació P2P empès a través de nous problemes, relacionats amb la seguretat. Per aquesta raó, la seguretat comença a convertir-se en una de les qüestions clau en l'avaluació d'un sistema P2P, i és important proporcionar mecanismes de seguretat per a sistemes P2P. El projecte JXTAOverlay fa un esforç per utilitzar la tecnologia JXTA per proporcionar un conjunt genèric de funcions que poden ser utilitzades pels desenvolupadors per desplegar aplicacions P2P. No obstant això, encara que el seu disseny es va centrar en qüestions com ara l'escalabilitat o el rendiment general, no va tenir en compte la seguretat. Aquest treball proposa un marc de seguretat, adaptat específicament a la idiosincràsia del JXTAOverlay.
Resumo:
In the wake of the success of Peer-to-Peer (P2P) networking, security has arisen as one of its main concerns, becoming a key issue when evaluating a P2P system. Unfortunately, some systems' design focus targeted issues such as scalabil-ity or overall performance, but not security. As a result, security mechanisms must be provided at a later stage, after the system has already been designed and partially (or even fully) implemented, which may prove a cumbersome proposition. This work exposes how a security layer was provided under such circumstances for a specic Java based P2P framework: JXTA-Overlay.
Resumo:
Modern multimedia communication tools must have high security, high availability and high quality of service (QoS). Any security implementation will directly impact on QoS. This paper will investigate how end-to-end security impacts on QoS in Voice over Internet Protocol (VoIP). The QoS is measured in terms of lost packet ratio, latency and jitter using different encryption algorithms, no security and just the use of IP firewalls in Local and Wide Area Networks (LAN and WAN). The results of laboratory tests indicate that the impact on the overall performance of VoIP depends upon the bandwidth availability and encryption algorithm used. The implementation of any encryption algorithm in low bandwidth environments degrades the voice quality due to increased loss packets and packet latency, but as bandwidth increases encrypted VoIP calls provided better service compared to an unsecured environment.
Resumo:
JXME is the JXTA protocols implementation formobile devices using J2ME. Two different flavors of JXME have been implemented, each one specific for a particular set of devices, according to their capabilities. The main value of JXME is its simplicity to create peer-to-peer (P2P) applications in limited devices. In addition to assessing JXME functionalities, it is also important to realize the default security level provided. This paper presents a brief analysis of the current state of security in JXME, focusing on the JXME-Proxied version, identifies existing vulnerabilities and proposes further improvements in this field.
Resumo:
Las redes móviles ad hoc son redes formadas por lainterconexión de terminales inalámbricos que de manera autónoma,sin ninguna administración central, establecen enlaces decomunicación entre ellos. La infraestructura de red la componenlos propios terminales de usuarios que actúan de gestores yencaminadores de paquetes. Así, un usuario cualquiera puedeconectarse con un terminal remoto a través de una conexiónmultisalto entre diferentes usuarios. En este tipo de redes tanabiertas, uno de los retos prioritarios es proteger el anonimatode los sujetos y sus localizaciones. En este artículo hacemos unrepaso de las técnicas existentes a través de los protocolos que sehan propuesto en la literatura, y exponemos los problemas queaun quedan abiertos.
Resumo:
La radio cognitiva es una tecnología inalámbrica propuesta para usar eficientemente los recursos del espectro radioeléctrico permitiendo así reducir la carga existente en las bandas de frecuencia de uso libre.Las redes de radio cognitiva son capaces de escanear el espectro y adaptar sus parámetros para operar en las bandas no ocupadas. Para evitar interferir con usuarios con licencia que operan en un determinado canal, la sensibilidad de las redes tiene que ser muy alta. Ello se consigue con métodos de detección cooperativos. Los métodos de detección cooperativa actuales tienen una carencia de robustez ya sea frente a ataques puntuales o continuos.En este artículo presentamos un método de fusión por grupos que tiene presente el comportamiento de los usuarios a corto y largo plazo. Al realizar la fusión de los datos, el método se basa en dar mayor peso a los grupos de usuarios con mayor unanimidad en sus decisiones.Los resultados de las simulaciones prueban que en presencia de atacantes el método de fusión por grupos propuesto consigue una detección superior a otros métodos, cumpliendo los requisitos de sensibilidad mínimos de las redes de radio cognitiva incluso con un 12 de usuarios reiteradamente maliciosos o un 10 de atacantes puntuales.
Resumo:
Cognitive radio networks sense spectrum occupancyand manage themselves to operate in unused bands without disturbing licensed users. Spectrum sensing is more accurate if jointly performed by several reliable nodes. Even though cooperative sensing is an active area of research, the secureauthentication of local sensing reports remains unsolved, thus empowering false results. This paper presents a distributed protocol based on digital signatures and hash functions, and ananalysis of its security features. The system allows determining a final sensing decision from multiple sources in a quick and secure way.