waashk/dblp huggingface dataset:
seas: a secure and efficient anonymity scheme for low-cost rfid tags. in this paper, we propose seas, a novel privacy preserving, anonymous authentication scheme for rfid tags, which allows the tags to use pseudonyms instead of their true identity for authentication. using seas, a tag generates random numbers and uses them to create a pseudonym as its identity for authentication. the pseudonym does not reveal the identity of the tag and the pseudonyms of multiple authentications appear random and uncorrelated to the adversary. a pseudonym can only be deciphered by the back-end authentication authority to identify the tag. no other entity in the network can link the pseudonym to the identity of the tag. our scheme is efficient, with a tag needing to perform only simple operations such as xor, bits shifting, bits concatenation, and random number generation. we perform security analysis of our scheme to show its effectiveness against different forms of attacks. we also perform comparison of our scheme with existing schemes in terms of efficiency in the use of resources. our scheme performs effectively, while at the same time being better than the other popular schemes in the literature in terms of cost and computation efficiency.
concurrent heap-based network sort engine - toward enabling massive and high speed per-flow queuing. a network sort engine (nse) that rapidly identifies the highest priority from numerous priorities is indispensable to enable per-flow queuing that supports massive queues in high-speed communications lines. this is because the bottleneck in per-flow queuing is the process to select a single queue to emit a frame from queues that are ready to emit frames; this process leads to sorting issues in identifying the highest priority. thus, a concurrent heap that parallelizes each layer of a binary tree has been developed as a method of implementing a massive and high speed nse. since it does not essentially modify conventional heap algorithms, it can work at high speed due to its lightweight memory management and it also ensures the worst-case runtime. as the fpga results from implementing the concurrent heap indicate that the required resources are very small, it could be implemented, in practice, in a small fpga, and the warranted runtime speed indicates that over 8,000 per-flow queues for a 10gbe lan-phy could work at the wire rate with successive minimum-length frames.
energy efficient collision aware multipath routing for wireless sensor networks. multipath routing can reduce the need for route updates, balance the traffic load and increase the data transfer rate in a wireless sensor network, improving the utilization of the limited energy of sensor nodes. however, previous multiple path routing methods use flooding for route discovery and transmit data with maximum power regardless of need, which results in waste of energy. moreover, often a serious problem of collisions among multiple paths arises. in this paper, we propose an energy efficient and collision aware (eeca) node-disjoint multipath routing algorithm for wireless sensor networks. with the aid of node position information, the eeca algorithm attempts to find two collision-free routes using constrained and power adjusted flooding and then transmits the data with minimum power needed through power control component of the protocol. our preliminary simulation results show that ecca algorithm results in good overall performance, saving energy and transferring data efficiently.
approximate expressions for cramer-rao bounds of code aided qam dynamical phase estimation. in this paper, we study bayesian and hybrid cramer-rao bounds (bcrb and hcrb) for the code-aided (ca) dynamical phase estimation of qam modulated signals. in order to avoid the calculus of the inverse of the bayesian information matrix and of the hybrid information matrix, we present some analytical expressions for the various crbs, which greatly reduce the computation complexity.
stereo image transmission over fading channels with multiterminal source coding. this paper addresses the problem of wireless delivery of a captured scene from two cameras, which do not communicate with each other, to a central point for joint decoding. we exploit correlation among two camera views using distributed source coding and use complete complementary (cc) data spreading to combat multiple access interference and noise even when the transmitters are de-synchronized. our distributed source coding scheme is based on uniform scalar quantization in the dct domain and non-asymmetric slepian-wolf coding via turbo codes. the non-asymmetric slepian-wolf scheme enables efficient trade-off between the transmission rates of the two cameras. simulation results indicate that the proposed system outperforms significantly two independently jpeg-encoded streams at low transmission rates.
green support for pc-based software router: performance evaluation and modeling. we consider a new generation of cots software routers (srs), able to effectively exploit multi-core/cpu hw platforms. our main objective is to evaluate and to model the impact of power saving mechanisms, generally included in today's cots processors, on the sr networking performance and behavior. to this purpose, we separately characterized the roles of both hw and sw layers through a large set of internal and external experimental measurements, obtained with a heterogeneous set of hw platforms and sr setups. starting from this detailed measure analysis, we propose a simple model, able to represent the sr performance with a high accuracy level in terms of packet throughput and related power consumption. the proposed model can be effectively applied inside "green optimization" mechanisms in order to minimize power consumption, while maintaining a certain sr performance target.
towards a gnu/linux ieee 802.21 implementation. multiaccess mobile devices and overlapping wireless network deployments have emerged as a next generation network fixture. to make the most of all available networks, mobile devices should be capable of handing over between heterogeneous networks seamlessly and automatically. at the same time, operators should be able to steer network attachment based on their criteria. although several cross layer mechanisms have been proposed in recent years, only the media independent handover (mih) services framework has advanced in any of the established standardization bodies. this paper presents a blueprint for a gnu/linux implementation of ieee 802.21. we review the salient points of the standard, introduce our software implementation architecture, detail information gathering in gnu/linux, and show how our prototype implementation can be used in practice. in contrast with prior published work, this paper presents a real ieee 802.21 implementation, not an abstracted or reduced mih-like framework, tested and empirically evaluated over real heterogeneous networks.
a decision theoretic approach to gaussian sensor networks. we consider the acquisition of measurements from a source, representing a physical phenomenon, by means of sensors deployed at different distances, and measuring random variables that are correlated with the source output. the acquired values are transmitted to a sink, where an estimation of the source has to be constructed, according to a given distortion criterion. in the presence of gaussian random variables and a gaussian vector channel, we are seeking optimum real-time joint source-channel encoder-decoder pairs that achieve a distortion sufficiently close to the theoretically optimal one, under a global power constraint, by activating only a subset of the sensors. the problem is posed in a team decision theoretic framework, and the optimal strategies are approximated by means of neural networks. we compare the solution with the results obtained by heuristically choosing a subset of the sensors on the basis of successive simulations under a fixed topology.
ofdma based multiparty medium access control in wireless ad hoc networks. we present the concurrent transmission or reception multiple access (ctrma) protocol as an example of embracing interference in wireless ad hoc networks, even when each node is endowed with a single half-duplex radio and a single antenna. ctrma uses ofdma to enable each node to either send or receive multiple concurrent transmissions over orthogonal subchannels (groupings of subcarriers). with ctrma, a node transmits multiple transmissions at the same time by negotiating the subchannels over which transmissions take place by using information attained with a channel priority assignment algorithm. ctrma supports dynamic bandwidth selection and enhances channel reuse. we prove the correctness of ctrma and use simulation experiments to illustrate the major performance advantages of ctrma over prior channel access protocols proposed for single-radio single-channel, single-radio multi-channel and multi-radio multi-channel wireless ad hoc networks.
traffic-matching revenue-rate maximization scheduling for downlink ofdma. in this paper, we study the weighted sum rate (w- rate) maximization algorithms with proportional rate fairness (prf) and delay constraints for the downlink orthogonal frequency division multiple access (ofdma) system. first, based on the lagrangian duality optimization tool, we design a weighted sum rate maximization scheme based on instantaneous transmit power and bit error rate (ber) constraints. second, to meet the rate fairness constraint imposed by different users' diverse traffic demands, we design a fast algorithm to search for the optimal weight factors, and implement the traffic-matching duality scheme to achieve the long-term target prf and enhanced revenue rate. third, we provide analytical channel throughput formulas for equal power allocation (epa) and waterfilling (wf) power allocations schemes, and also evaluate the actual throughput taking into account the traffic random arrival process, limited buffer size, and transmission delay deadline. simulation results show that the proposed traffic-matching duality scheme can achieve a significantly higher revenue rate than the fixed weight duality scheme which only tries to maximize the revenue rate but does not match the incoming traffic.
load aware broadcast in mobile ad hoc networks. in a wireless ad hoc network, the main issue of a good broadcast protocol is to attain maximum reachability with minimal packet forwarding. existing protocols address this issue by utilizing the knowledge of up to 2-hop neighbors to approximate an mcds (minimum connected dominating set) via heuristics derived from techniques known as self pruning and dominant pruning. our experiments show that, using these greedy choice heuristics result in a biased load distribution throughout the network. some nodes become heavily loaded and consequently packets through those nodes, whether unicast or broadcast, experience significantly larger delay. contention and collision also increase at some regions, while they are relatively low at other regions. in this paper we address these issues, and propose various methods to evenly distribute the load caused by broadcast packets. our algorithms take various reactive measures to dynamically include less loaded nodes in the forward list, while maintaining total number of packet forwards low. detailed simulation using ns-2 shows fair scheduling of resources and significant improvement in distribution of packet forwarding load, packet delay, latency and overall performance.
on hashing with tweakable ciphers. cryptographic hash functions are often built on block ciphers in order to reduce the security analysis of the hash to that of the cipher, and to minimize the hardware size. well known hash constructs are used in international standards like md5 and sha-1. recently, researchers proposed new modes of operations for hash functions to protect against generic attacks, and it remains open how to base such functions on block ciphers. an attracting and intuitive choice is to combine previous constructions with tweakable block ciphers. we investigate such constructions, and show the surprising result that combining a provably secure mode of operation with a provably secure tweak-able cipher does not guarantee the security of the constructed hash function. in fact, simple attacks can be possible when the interaction between secure components leaves some additional "freedom" to an adversary. our techniques are derived from the principle of slide attacks, which were introduced for attacking block ciphers.
exposure-path prevention in directional sensor networks using sector model based percolation. in wireless sensor networks, most existing works on region coverage mainly concentrate on the omnidirectional sensor based full coverage, which ensures that all points in the sensor-deployed region are covered. in contrast, this paper studies the problem of exposure-path prevention for the region coverage in directional sensor networks. because the exposure paths are prevented as long as no moving objects or phenomena can go through a sensor-deployed region without being detected, exposure-path prevention does not require full coverage, and instead it only needs the partial coverage. towards this end, we apply the percolation theory to solve the exposure path problem for directional sensor networks. in particular, we map the exposure path problem into a sector based percolation model, and then derive the bounds of critical density where directional sensors are deployed according to a 2-dimensional poisson process. also conducted is a set of extensive simulations to validate and evaluate our developed models and schemes.
iris recognition using combination of dual tree rotated complex wavelet and dual tree complex wavelet. the increasing requirement of security due to advances in information technologies, especially e-commerce have led to rapid development of personnel identification /recognition systems based on biometric. a remarkable and important characteristic of the iris is the randomly distributed irregular texture details in all directions. in this paper, the authors have proposed a novel approach of feature extraction of iris image using 2d redundant rotated complex wavelet transform (rcwt) in combination with 2d dual trace complex wavelet transform(dt-cwt) to obtains the features in 12 different directions as against 3 and 6 directions in discrete wavelet transform (dwt) and complex wavelet transform (cwt) respectively. iris features are obtained by computing energies and standard deviation of detailed coefficients in 12 directions. the sub-bands f rcwt are derived from sub-bands of cwt by using the suitable mapping rules. canbera distance is used for matching. the results are obtained using dwt, cwt and combination of cwt and rcwt on ubiris database of 2400 images. the performance measure, zerofar is reduced from 6.3 using dwt to 2.9 using the proposed method. the method is also computationally efficient as compared to gabor filters.
ipsec-based anonymous networking: a working implementation. protecting users' privacy is becoming one of the rising issues for the success of future communications. the internet in particular, with its open architecture, presents several threats to the right of protecting personal and sensitive data. one fundamental building block of privacy-respectful communications is protecting the communication parties identities, or, as it is commonly called within the research community anonymous networks (ans). an an prevents external observers as well as the network to have access to communicating partners identities and addresses. in this paper we propose a novel architecture to realize ans, as an extension to ipsec. after explaining the rationale and discussing possible alternatives, we present a working prototype implementation and its experimental performance comparison with application level solutions.
coopmax: a cooperative mac with randomized distributed space-time coding for an ieee 802.16 network. cooperative communication is a technique that can be employed to meet the increased throughput needs of next-generation wimax systems. in a cooperative scenario, multiple stations can jointly emulate the antenna elements of a multi-input multi-output (mimo) system in a distributed fashion. although distributed space-time coding (dstc) is being considered by the ieee 802.16j/16m standards for spatial diversity gain, it has several inherent drawbacks. these are addressed in the recently invented randomized distributed space-time coding, called r-dstc. in this paper, we present the framework for the r-dstc technique in the emerging relay-assisted wimax network, and develop a cooperative medium access control (mac) layer protocol, called coopmax, for r-dstc deployment in an ieee 802.16 system. our scheme couples the mac layer with the physical (phy) layer for performance optimization. the phy layer yields significant diversity gain, while the mac layer achieves a substantial end-to-end throughput gain. through extensive simulations, we evaluate the performance of coopmax and show that it can generate capacity gains of up to about 77% for an ieee 802.16 network.
efficient gsvd based multi-user mimo linear precoding and antenna selection scheme. we present a multi-user multiple-input multiple-output (mu-mimo) precoding scheme utilizing generalized singular value decomposition (gsvd). our work is motivated by the precoding scheme developed by sadek, tarighat, and sayed that maximizes the signal to leakage and noise ratio (slnr), in which the precoding weight is obtained by the generalized eigenvalue decomposition (gevd). however, the covariance matrix utilized in gevd becomes close to be singular as the signal to noise ratio goes high. to improve the numerical accuracy, a gsvd based algorithm is exploited in this paper and a novel method is derived to compute the precoding weights for multiple users by removing redundant computational loads rather than repeating the gsvd algorithm for each user. in addition, we propose a technique to speed up the gsvd based precoding algorithm by preprocessing using the qr decomposition. finally, to improve the system performance, the antenna selection scheme using gsvd is also proposed which does not require the exhaustive search to choose the active antennas.
distributed power control for interference-limited cooperative relay networks. in this paper, a distributed power control algorithm is proposed for wireless relay networks in interference-limited environments. the objective is to minimize the total transmission power while satisfying the signal-to-interference-plus-noise ratio (sinr) requirements. two forwarding techniques, i.e., decode-and-forward (df) and amplify-and-forward (af), are considered. the proposed algorithm only requires locally measured sinr on the relay nodes (rns) and the destination nodes (dns), based on which each cooperation unit (defined as one source node (sn) and dn pair with the rn associated to it) iteratively updates the transmission power of the sn and the rn by solving a local optimization problem. we prove that the convergence is guaranteed when the parameters adopted in the algorithm are sufficiently large, and then a parameter adjusting method is also designed. simulation results indicate that the proposed algorithm converges fast and leads to only 7% more power consumption than the optimal power allocation in the considered scenarios. it is also shown that even in interference-limited environments, relaying can still improve system performance substantially in terms of outage and power consumption.
performance gain of space-time-frequency concatenated ldpc codes. this paper introduces a stfc-ldpc (space-time-frequency code low density parity check) concatenated coding scheme for high performance mimo (multiple input, multiple output) systems. the coding design and performance evaluation are illustrated for various frequency-selective block fading conditions and compared with a stc-ldpc (space-time code ldpc) concatenated scheme over quasi-static fading conditions. the codes were analyzed and compared in space-selective conditions using various pdps (power-delay profiles) to illustrate the performance gain of this newly proposed coding technique. the proposed stfc-ldpc showed a performance increase compared to the stc-ldpc scheme due to the inherent higher diversity of the stfc and is a suitable coding technique for high performance mimo systems.
joint detection and estimation for cooperative communications in cluster-based networks. this paper considers the joint symbol detection and channel estimation problem for cooperative communications in cluster-based networks. the proposed joint detection and estimation scheme is derived by using the expectation maximization (em) algorithm. in addition, the cooperative communication between the relays and the destination is based on the concept of compress-and-forward (cf) scheme. most importantly, the distribution detection theory is incorporated in developing the joint detection and estimation rules. specifically, each relay makes its decision based on its joint detection and estimation rule and then forwards it to the destination node. the destination node makes a decision by fusing the decisions sent from the relays using its joint detection and estimation rule. in our considered structure, the feedback channels are also allowed from the destination node to all the relays to further improves the performance of cooperative communications. the simulation results show that the performance of cooperative communication can improve significantly by using the fusion technique and the feedback channels.
policy-based security configuration management, application to intrusion detection and prevention. intrusion detection and/or prevention systems (idps) represent an important line of defense against the variety of attacks that can compromise the security and well functioning of an enterprise information system. idpses can be network or host-based and can collaborate in order to provide better detections of malicious traffic. although several idps systems have been proposed, their appropriate configuration and control for effective detection and prevention of attacks has always been far from trivial. another concern is related to the slowing down of system performance when maximum security is applied, hence the need to trade off between security enforcement levels and the performance and usability of an enterprise information system. in this paper we motivate the need for and present a policy-based framework for the configuration and control of the security enforcement mechanisms of an enterprise information system. the approach is based on dynamic adaptation of security measures based on the assessment of system vulnerability and threat prediction and provides several levels of attack containment. as an application, we have implemented a dynamic policy-based adaptation mechanism between the snort signature-based idps and the light weight anomaly-based firecollaborator ids. experiments conducted over the darpa 2000 and 1999 intrusion detection evaluation datasets show the viability of our framework.
mmse-based non-regenerative multicarrier mimo wireless relay communications with direct source-destination link. in this paper we propose non-regenerative multi-carrier multiple-input multiple-output (mimo) relay techniques that minimize the mean-squared error (mse) of the signal wave-form estimation. in particular, we consider the practical scenario where the direct source-destination link can not be neglected and develop an alternating technique to minimize the signal mse. in order to reduce the computational complexity of the alternating algorithm, a suboptimal non-alternating precoding approach is proposed. numerical examples illustrate a significant performance improvement of the proposed algorithms compared with the existing techniques.