The most interesting authorization operation types are RemoveUserFromGroup and RemoveGroupFromGroup on the one hand, since the processing of these event types works completely different from that in the E2E-SDS protocols based on joint au- thorization operations, and potentially requires a lot of resources. As already shown, these event types occur only rarely in the real-world workloads. Because of the small sample size, synthetic workloads are used to assess the sensitivity of the performance with regard to certain workload parameters, which is presented in the next subsec- tion. Nonetheless, the real-world results might give a first indication for the employ- ability of the protocol. Removing a user from a group takes 38 s (40 s; 99 s) in average, and a maximum of 911 s (935 s; 1608 s) was observed. The removal of a group from another group takes 48 s (56 s; 320 s) on average, which is slightly more than for a user removal at the Dell laptop and the Samsung Galaxy S5 mini smartphone, and about two times more on the iPhone 3G. The higher computation times for the removal of a group can be explained by the necessary renewal of the key hierarchies of all descendant groups, which is omitted in case of a user removal. Besides lots of sym- metric cryptographic operations, the key hierarchy renewal requires one asymmetric encryption per group member. These asymmetric operations takes a comparatively long time, especially on the old iPhone.
Figure 2 presents the cumulative distributions of RTTs from the probing computer to the distant server in six con- figurations (we omit the other WiFi scenarios because the conclusions are similar to their Ethernet counterparts). The RTTs range from 60 ms to more than 1 s, which shows that end-to-endperformance of a computer in a home depends strongly on home usage. The highest impact on end-to-endperformance comes from a competing computer in the home. The RTT can reach 120 ms when a competing computer does a download. This impact is even higher for uploads, RTTs are never lower than 180 ms and even larger than 1 second 60% of the cases. Uploads have a larger impact than down- loads because of the high asymmetry of the ADSL line with a much lower uplink rate. The other noticeable difference is between WiFi and Ethernet. For Ethernet/Idle, RTTs are always close to 60 ms. For WiFi/Idle, RTTs have more vari- ance and can reach larger values (up to 80 ms). Note that to save space we have put many curves in Figure 2 and
Abstract. NETI@home is an open-source software package that collects network performance statistics from end-systems. It has been written for and tested on the Windows, Solaris, and Linux operating systems, with testing for other operating systems to be completed soon. NETI@home is designed to run on end-user machines and collects various statistics about Internet performance. These statistics are then sent to a server at the Georgia Institute of Technology, where they are collected and made publicly available. This tool gives researchers much needed data on the end-to-endperformance of the Internet, as measured by end-users. Our basic approach is to sniff packets sent from and received by the host and infer performance metrics based on these observed packets. NETI@home users are able to select a privacy level that determines what types of data are gathered, and what is not reported. NETI@home is designed to be an unobtrusive software system that runs quietly in the background with little or no intervention by the user, and using few resources.
Differences from Cognitive Networks — Cognitive networks are clearly delineated from cognitive radios by the scope of the controlling goals. Goals in a cognitive network are based on end-to-end network performance, whereas cog- nitive radio goals are localized only to the radio’s user. These end-to-end goals are derived across the network from operators, users, applications, and resource requirements. This difference in goal scope from local to end-to-end enables the cognitive network to operate more easily across all layers of the protocol stack. Current research in cognitive radio emphasizes interactions with the physical layer, which limits the direct impact of changes made by the cognitive process to the radio itself and other radios to which it is direct- ly linked. Agreement with other radios on parameters which must match for successful link communication is reached through a process of negotiation. Since changes in protocol layers above the physical layer tend to impact more nodes in the network, the cognitive radio negoti- ation process would have to be expanded to include all nodes impacted by the change. How- ever, because the negotiation process is unable to assign precedence to radios’ desires without goals of a broader scope, achieving agreement among multiple nodes may be a slow process. For the same reason, the compromise can be expected to result in suboptimal network perfor- mance. In contrast, cognitive networks are more
BPSK modulation in real AWGN and then was extended to higher orders of modulation in complex channels. In , the second-order and fourth-order moments (M2M4) estimator was studied using the second- and fourth-order moments of the signal to avoid carrier phase recovery. In , signal- to-variation ratio (SVR) estimator was designed for M-ary PSK-modulated signals. An in-service SVR estimator for complex channels was also developed. All these estimators provide efficient estimation of SNR for different applica- tions. However, their performances were only evaluated for the traditional one-hop systems in . In order to improve performance for signal-to-noise ratio (SNR) estimator a new method has been proposed in . For non-constant modulus constellations over flat-fading channel a new SNR estimation have been discussed in . Signal-to-noise estimatation in time-varying fading channels have been considered in . It is not clear how these estimators will perform in a relaying system that adopts two or more hops, as it is the end-to-end SNR that determines the performance of a relaying system. The exact end-to-end SNR describes the actual relaying per- formance but is complicated . Several bounds have been proposed to simplify it. The harmonic mean has the math- ematical tractability but is only a tight upper bound at high SNR . The minimum hop SNR is a good indication of the asymptotic performance of the relaying system .
The PingER project has been hugely successful and continues to provide valuable insight into network performance. The many years of data taking provides a unique source for quantifying long-term trends. The effect of upgrades and vacations can be seen. PingER also provides evidence of the effect of policy changes. For example, the impact of peering arrangements and routing policy. PingER as a research project has provided the data for end users to understand what is going on in the network. PingER as a trouble- shooting tool continues to provide valuable evidence to direct administrators to address the problem. The accompanying presentation shows graphs selected from PingER monitoring that detail this value.
Evidently, it is possible to discover at this stage that the required improve- ments in the execution of the activities of the system might be infeasible to achieve, especially in the setting of weak computing devices such as smartcards or low-end PDAs or in a thin client context with intermittent or very narrow bandwidth connections between devices. If this is the case, then a developer working at the early modelling stage of the system development process would need to revisit the initial protocol design and perhaps re-design this to involve fewer message exchanges or reduce the amount of asymmetric cryptography used. This will initiate another cycle of security analysis and performance analysis in pursuit of the levels of security and performance demanded of the system.
Vehicular Ad Hoc Network (VANET) is sub group of mobile ad hoc network (MANET).This network are becoming the main stream of network research have been carried out from many aspects. It is an emerging new technology to exchange the information between vehicles to vehicles. This technology considered as one of most noticeable technologies for improving the efficiency and safety of transportation system. For the development of the intelligent transport system (ITS) having the ability for both self-management and also self- organization, making them reliable as a highly mobile network system.In this paper I will survey different method which involves evaluation of performance in vehicular ad hoc network with various parameters, for this various protocols from two classes (unicast and multicast) of routing in VANET are implemented.
In a utility environment where multiple services converge over a common infrastructure, QoS is essential. The Alcatel-Lucent IP/MPLS network can discriminate among various types of traffic, based on a rich set of classification attributes at Layer 1, Layer 2, Layer 2.5, or Layer 3 and prioritize transmission of higher priority traffic over lower priority. It utilizes extensive traffic management using an advanced scheduling mechanism to implement service hierarchies. These hierarchies provide maximum isolation and fairness across different traffic while optimizing uplink utilization. With multiple levels and instances of shaping, queuing and priority scheduling, the Alcatel-Lucent IP/MPLS network can manage traffic flows to ensure that performance parameters (such as bandwidth, delay and jitter) for each application are met.
Given the current trends in designing a “clean-slate” future Internet, our findings motivate the need for a secure next-generation Internet. We argue that any next-generation Internet design must provide robust functionality to support secure network measurements . Since network measurements are gaining paramount importance in monitoring the performance of the Internet, secure infrastructural support for network measurements becomes rather a necessity. We can identify a number of reasons why it might be beneficial to embed parts of the measurement functions “inside the network”: 1) by performing measurements at an intermediate point, end-users can avoid the cost and overhead of generating unwel- come traffic across the network, 2) by pushing functionality from end-hosts to dedicated and trusted network components, several security threats can be eliminated. For instance, edge routers could securely timestamp incoming and outgoing probes and identify whether queuing has occurred . This would facilitate the detection of delay attacks. Performance “awareness” is another desirable design property for next-generation Internet. Dedicated network components could in the future construct and store bandwidth and latency maps of Internet hosts by monitoring incoming and outgoing traffic.
Providing quality inputs is not always practical since this depends upon so many environmental factors in one way or another. As this work focuses on fingerprint biometric – a scanner or any other machine that take the input fingerprint image is concerned and that would depend on factors such as proper alignment of fingerprint, lightings in the surroundings, proper dots per pixels settings in the machine, format of storing the image, cuts and bruises in the finger etc. Minutiae based approach is very much sensitive to noise and deformations. For instance false ridge endings and bifurcations may appear due to blurred or over inked problems. More over ridge endings and bifurcations may disappear when a finger is pressed too hard or too light i.e. the performance of minutiae extraction algorithms relies heavily on the quality of the fingerprint. If the quality of the image is checked first, then it is possible to reject the image with very poor quality. It is therefore desirable to design an automatic scheme that examines and quantifies the quality of the acquired fingerprint image before it is processed.
13]. Other works have focused on measuring and characterizing the one-way delay of 3G/HSPA networks [4, 7]. Winstein et al. also mentioned in passing that packet arrivals on LTE links do not follow an observable isochronicity . Jiang et al. measured the buffers of 3G/4G networks for the four largest U.S. carriers as well as the largest ISP in Korea using TCP and examined the bufferbloat problem . Our work extends their work by investigating the buffer sizes and queuing policies of mobile ISPs, and we found some surprising differences among the three local ISPs. Aggarwal et al. discussed the fairness of 3G networks and found that the fairness of TCP is adversely affected by a mismatch between the congestion control algorithm and the network’s scheduling mech- anism . A recent study also showed various interesting effects of network protocols and application behaviors on the performance of LTE networks .
In this paper, we present an end-to-end pipeline for sentiment analysis of a popular micro-blogging website called Twitter. We acknowledge that much of current research adheres to parts of this pipeline. However, to the best of our knowledge, there is no work that explores the classifier design issues explored in this paper. We build a hierarchal cascaded pipeline of three models to label a tweet as one of Objective, Neutral, Positive, Negative class. We compare the performance of this hierarchal pipeline with that of a 4-way classification scheme. In addition, we explore the trade-off between making a prediction on lesser number of tweets versus F1-measure. Overall we show that a cascaded design is better than a 4-way classifier design.
This paper shortly describes the already standardized SCTP security solutions, namely SCTP over IPsec  and TLS over SCTP  and identifies their limitations. It will be shown that these functional and performance re- lated limitations can be overcome by integrating security functions directly into SCTP as proposed by us in earlier publications under the name S-SCTP (see ,  and ). One problem remaining with S-SCTP is that a full scale introduction would require these extensions of SCTP to be included in future operating system kernels. Therefore, and based on the discussions in the IETF , we propose an alternative security solution for SCTP which is based on the use of the newly defined Datagram TLS protocol (see  and ) in combination with the chunk authentication extension of SCTP  currently under standardization in the IETF. We will describe the concept of this ”SCTP aware DTLS” solution in detail to substantiate its feasibility. In addition, we will discuss some aspects of an implementation based on OpenSSL. With kind permission of Springer Science and business Media.
Abstract—Short Message Service (SMS) is a widely used communication medium, including by mobile applications, such as banking, social networking, and e-commerce. Applications of SMS services also include real-time broadcasting messages, such as notification of natural disasters (e.g. bushfires and hurricane) and terrorist attacks, and sharing the current whereabouts to a group of friends, such as notifying urgent business meeting information, transmitting quick information in the battlefield to multiple users, notifying current location to our friends, and sharing market information. However, traditional SMS is not designed with security in mind (e.g. messages are not securely sent). It is also possible to extract International Mobile Subscriber Identity (IMSI) of the mobile user. In literature, there is no known protocol that could enable secure transmission of SMS from one user to multiple users simultaneously. In this paper, we introduce a batch verification Authentication and Key Agreement (AKA) protocol, BVPSMS, which provides end-to-end message security over an insecure communication channel between different Mobile Subscribers (MSs). Specifically, the proposed protocol securely transmits SMS from one MS to multiple MS simultaneously. The reliability of the protocol is discussed along with an algorithm to detect malicious user request in a batch. We then evaluate the performance of the BVPSMS protocol in terms of communication and computation overheads, protocol execution time, and batch and re-batch verification times. The impacts of the user mobility, and the time, space, and cost complexity analysis are also discussed. We also present a formal proof of the security of the proposed protocol. To the best of our knowledge, this is the first provably-secure batch verification AKA protocol, which provides end-to-end security to the SMS using symmetric keys.
networking, and e-commerce. Applications of SMS services also include real-time broadcasting messages, such as notification of natural disasters (e.g., bushfires and hurricane) and terrorist attacks, and sharing the current whereabouts to other users, such as notifying urgent business meeting information, transmitting quick information in the battlefield to multiple users, notifying current location to our friends and sharing market information. However, traditional SMS is not designed with security in mind (e.g., messages are not securely sent). It is also possible to extract international mobile subscriber identity of the mobile user. In the literature, there is no known protocol that could enable secure transmission of SMS from one user to multiple users simultaneously. In this paper, we introduce a batch verification authentication and key agreement protocol, BVPSMS, which provides end-to-end message security over an insecure communication channel between different mobile subscribers. Specifically, the proposed protocol securely transmits SMS from one mobile user to multiple users simultaneously. The reliability of the protocol is discussed along with an algorithm to detect malicious user request in a batch. We then evaluate the performance of the proposed protocol in terms of communication and computation overheads, protocol execution time, and batch and re-batch verification times. The impacts of the user mobility, and the time, space and cost complexity analysis are also discussed. We then present a formal security proof of the proposed protocol. To the best of our knowledge, this is the first provably-secure batch verification protocol that delivers end-to-end SMS security using symmetric keys.
The back-pressure rule, whereas being throughput-optimal, is not helpful in follow for reconciling routing since the delay performance are often very dangerous. during this paper, we have presented associate rule that routes packets on shortest hops when doable and decouples routing and planning employing a probabilistic ripping rule engineered on the construct of shadow
Unfortunately, despite the presence of various protection techniques, data corruption still occurs. Rare events such as dropped writes or misdirected writes leave stale or corrupt data on disk , , , . Bits in memory get flipped due to chip defects , ,  or radiation , . Software bugs are also a source of data corruption, arising from low-level device drivers , system kernels , , and file systems , . Even worse, design flaws are not uncommon and can lead to serious data loss or corruption . While many features that storage systems provide require great care and coordination across the many layers of the system (e.g., performance), integrity checks for data protection generally remain isolated within individual components. For example, hard disks have built-in ECC for each sector , but the ECCs are rarely exposed to the upper-level system; TCP uses Internet checksums to protect data payload , but only during the transmission. When data is transferred across components, data is not protected and thus may become silently corrupted.