KINGMAXSSD新品SMP32 client展示

近日KINGMAX固态硬盘产品线再度刷新。推出了最新款的SATAⅢ固态硬盘系列产品SMP32Client。该系列SATAⅢ固态硬盘采用最新的Sand Force控制晶片,搭配高速NANDFlash颗粒及标准6Gb／s传输介面．不但最高读取速度一举突破550MB／s．写入速度最高也可达520MB／s．性能及稳定度更大大提升,再次展现KINGMAX在固态硬盘产品的强大研发实力。     

The impact of psychological contract under- and over-fulfillment on client citizenship behaviors in Enterprise systems projects: From the client’s perspective

This study focuses on examining client citizenship behaviors (CCBs) from a psychological contract perspective in enterprise systems (ES) vendor–client relationships. Using polynomial modeling to capture the discrepancy between expected obligations and delivered fulfillments, this stud unpacks psychological contract and investigates the impacts of psychological contract under-fulfillment, fulfillment, and over-fulfillment on CCBs. The results show that both under-fulfillment and over-fulfillment of psychological contract are negatively related to CCBs. CCBs are shown to be higher when expected obligation and delivered fulfillment are both high than when both are low. The theoretical contributions and practical implications are discussed.     

The initiation and adoption of client–server technology in organizations

A large number of companies are adopting client–server systems. We investigated the relationship between several contextual factors and the initiation and adoption process of this important technology. The contextual factors included: (a) environmental, such as market position; (b) internal factors, namely organizational structure/culture, size, and migration strategy; and (c) technological, such as scope, scale, and cost of a system. An analysis of data from 350 companies revealed that a company's market position, its migration strategy, and the system's scope and scale have a significant effect on the initiation and adoption process.     

在ORACLE client／server上开发大型数据库的问题及解决

本文提出在大型数据库应用开发中，ＯＲＡＣＬＥ Ｖ６．０ ｃｌｉｅｎｔ／ｓｅｒｖｅｒ保护方式及实方式存在的问题，并分别给出了解决方法，文中的工作是在ＴＣＰ／ＩＰ上进行的，但对Ｎｏｖｅｌｌ及其它网络同样有意义。     

An efficient user authentication and key exchange protocol for mobile client–server environment

Considering the low-power computing capability of mobile devices, the security scheme design is a nontrivial challenge. The identity (ID)-based public-key system with bilinear pairings defined on elliptic curves offers a flexible approach to achieve simplifying the certificate management. In the past, many user authentication schemes with bilinear pairings have been proposed. In 2009, Goriparthi et al. also proposed a new user authentication scheme for mobile client–server environment. However, these schemes do not provide mutual authentication and key exchange between the client and the server that are necessary for mobile wireless networks. In this paper, we present a new user authentication and key exchange protocol using bilinear pairings for mobile client–server environment. As compared with the recently proposed pairing-based user authentication schemes, our protocol provides both mutual authentication and key exchange. Performance analysis is made to show that our presented protocol is well suited for mobile client–server environment. Security analysis is given to demonstrate that our proposed protocol is provably secure against previous attacks.     

A secure and efficient identity-based authenticated key exchange protocol for mobile client–server networks

Recently, Chou et al. (J Supercomput 66(2): 973–988, 2013) proposed two identity-based key exchange protocols using elliptic curves for mobile environments. The first one is an two-party authentication key exchange protocol to establish a session key between a client and a remote server. The second one is an extended version for three-party setting to establish a session key between two clients with the help of a trusted server. However, this paper finds the first one vulnerable to impersonation attack and key-compromise impersonation attack, and the second one insecure against impersonation attack. To overcome the weaknesses, we propose an improved identity-based two-party authentication key exchange protocol using elliptic curves. The rigorous analysis shows that our scheme achieves more security than related protocols.     

Cryptanalysis of a remote user authentication scheme for mobile client–server environment based on ECC

Understanding security failures of cryptographic protocols is the key to both patching existing protocols and designing future schemes. The design of secure remote user authentication schemes based on elliptic curve crypto-graphy (ECC) for mobile applications is still quite a challenging problem, though many schemes have been published lately. In this paper, we analyze an efficient ID-based scheme for mobile client–server environment without the MapToPoint function introduced by He et al. in 2012. This proposal attempts to overcome many of the well known security and efficiency shortcomings of previous schemes, and it also carries a claimed proof of security in the random oracle model. However, notwithstanding its formal security arguments, we show that He et al.’s protocol even cannot attain the basic goal of mutual authentication by demonstrating its vulnerabilities to reflection attack and parallel session attack. Besides these two security vulnerabilities, their scheme also suffers from some practical pitfalls such as user anonymity violation and clock synchronization problem. In addition, we carry out an investigation into their security proof and propose some changes to the scheme so that it can achieve at least its basic security goal, in the hope that similar mistakes are no longer made in the future.     

Remote user authentication and key agreement for mobile client–server environments on elliptic curve cryptography

In recent years, with the rapid advance of wireless mobile networks, secure and efficient authentication mechanisms that can operate over insecure wireless channels have become increasingly essential. To improve the efficiency in the energy-limited mobile devices, many authentication schemes using elliptic curve cryptography (ECC) have been presented. However, these schemes are still inefficient in terms of computation cost and communication overhead. Moreover, they suffer from various attacks, making them impractical due to their inherent design. To address their weaknesses, we propose a more efficient ID-based authentication scheme on ECC for mobile client–server environments with considering security requirements. The proposed scheme not only provides mutual authentication but also achieves session key agreement between the client and the server. Through a rigorous formal security proof under random oracle model, it has been indicated that the proposed protocol is secure against security threats. The informal security analysis shows that our scheme can resist well-known attacks and provides user anonymity. Performance analysis and comparison results demonstrate that our scheme outperforms the related competitive works and is more suitable for practical application in mobile client–server environments.     

Quantification of interacting runtime qualities in software architectures: Insights from transaction processing in client–server architectures

ContextArchitecture is fundamental for fulfilling requirements related to the non-functional behavior of a software system such as the quality requirement that response time does not degrade to a point where it is noticeable. Approaches like the Architecture Tradeoff Analysis Method (ATAM) combine qualitative analysis heuristics (e.g. scenarios) for one or more quality metrics with quantitative analyses. A quantitative analysis evaluates a single metric such as response time. However, since quality metrics interact with each other, a change in the architecture can affect unpredictably multiple quality metrics.ObjectiveThis paper introduces a quantitative method that determines the impact of a design change on multiple metrics, thus reducing the risks in architecture design. As a proof of concept, the method is applied on a simulation model of transaction processing in client server architecture.MethodFactor analysis is used to unveil latent (i.e. not directly measurable) quality features represented by new variables that reflect architecture-specific correlations between metrics. Separate Analyses of Variance (ANOVA) are then applied to these variables, for interpreting the tradeoffs detected by factor analysis in terms of the quantified metrics.ResultsThe results for the examined transaction processing architecture show three latent quality features, the corresponding groups of strongly correlated quality metrics and the impact of architecture characteristics on the latent quality features.ConclusionThe proposed method is a systematic way for relating the variability of quality metrics and the implied tradeoffs to specific architecture characteristics.     

A proxy-based integrated cache consistency and mobility management scheme for client–server applications in Mobile IP systems

In this paper, we investigate a proxy-based integrated cache consistency and mobility management scheme for supporting client–server applications in Mobile IP systems with the objective to minimize the overall network traffic generated. Our cache consistency management scheme is based on a stateful strategy by which cache invalidation messages are asynchronously sent by the server to a mobile host (MH) whenever data objects cached at the MH have been updated. We use a per-user proxy to buffer invalidation messages to allow the MH to disconnect arbitrarily and to reduce the number of uplink requests when the MH is reconnected. Moreover, the user proxy takes the responsibility of mobility management to further reduce the network traffic. We investigate a design by which the MH’s proxy serves as a gateway foreign agent (GFA) as in the MIP Regional Registration protocol to keep track of the address of the MH in a region, with the proxy migrating with the MH when the MH crosses a regional area. We identify the optimal regional area size under which the overall network traffic cost, due to cache consistency management, mobility management, and query requests/replies, is minimized. The integrated cache consistency and mobility management scheme is demonstrated to outperform MIPv6, no-proxy and/or no-cache schemes, as well as a decoupled scheme that optimally but separately manages mobility and service activities in Mobile IPv6 environments.     

Windows环境下的标准TCP/IP网络开发环境(三)——WinSock client程序的设置

从用户的角度出发，介绍ＷｉｎＳｏｃｋｃｌｉｅｎｔ应用程序的安装和设置步骤