984 resultados para Forgery attacks


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Since its inception in 1921, a number of successive regimes have sought to politicize Iraq‟s cultural history in order to develop national identity and foster social cohesion across this rich and complex nation. Foremost among these were the Baath party, particularly under the rule of Saddam Hussein, who used much of the nation‟s Oil wealth to undergo an extensive nation-building campaign. However, identity in Iraq is far from monolithic and various factions have long resisted the state sanctioned version of “Iraqi” identity and asserted alternative histories and narratives to underpin their own identity politics. With the invasion of Iraq by Coalition forces in 2003, however, came an unprecedented era of cultural destruction. Following the devastation of the battle phase of the war, there were further attacks on Iraq‟s cultural heritage including everything from the carefully choreographed removal of the giant bronze statue of Saddam in Firdos square, through to military bases set up at sensitive archaeological sites such as the ancient city of Babylon. In addition, Iraqi civilians targeted the cultural history of their nation with wanton looting and arson, as well as systematic attacks on sites of archaeological or ethno-religious significance. More recently, the Shia and Kurdish dominated Iraqi Government have organised the “Committee for Removing Symbols of the Saddam Era” and drew up plans to purge the state of its Sunni dominated past.

This paper argues that the unprecedented scale and magnitude of the destruction of Iraq‟s cultural history has played a part in eroding the various intersecting and overlapping versions of identity politics in Iraq. In turn, this has provided fertile ground for terrorists and sectarians to plant the seeds of their own narrow and deadly ideologies. This has brought about the rise of ethno-religious based violence and seen a series of bloody and protracted conflicts emerge between previously peaceful and compatible factions. In this way, Iraq serves as a powerful case study in furthering academic discussion on the complex inter-relationships between cultural and historical destruction and identity politics, sectarianism, violence and democracy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Since its inception in 1921, a number of successive regimes have sought to politicize Iraq’s cultural history in order to build nationalistic sentiment and social cohesion across this rich and complex nation. Foremost among these were the Baath party, particularly under the rule of Saddam Hussein, who used much of the nation’s Oil wealth to undergo an extensive nation-building campaign. However, with the invasion of Iraq by the US in 2003 came the deliberate destruction and blatant negligence of the occupying forces. In addition, Iraqi civilians targeted the cultural landscape of their nation with wanton looting and arson, as well as systematic attacks on sites of archaeological or ethno-religious significance. More recently, the Shia and Kurdish dominated Iraqi Government have organised the “Committee for Removing Symbols of the Saddam Era” and plan to purge the state of its Sunni dominated past. This paper argues that the destruction of Iraq’s cultural history has played a part in eroding the national identity that many of these symbols and institutions were designed to promulgate. In turn, this has brought about the rise of ethno/religious sectarianism in Iraq which has had particular implications for the nation’s fledgling democratic order.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Stepping stone attacks are often used by network intruders to hide their identities. To detect and block stepping stone attacks, a stepping stone detection scheme should be able to correctly identify a stepping-stone in a very short time and in real-time. However, the majority of past research has failed to indicate how long or how many packets it takes for the monitor to detect a stepping stone. In this paper, we propose a novel quick-response real-time stepping stones detection scheme which is based on packet delay properties. Our experiments show that it can identify a stepping stone within 20 seconds which includes false positives and false negatives of less than 3%.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Stepping stone attacks are often used by network intruders to hide their identities. The Round Trip Times (RTT) between the send packets and corresponding echo packets for the connection chains of stepping stones are critical for detecting such attacks. In this paper, we propose a novel real-time RTT getting algorithm for stepping stones which is based on the estimation of the current RTT value. Our experiments show that it is far more precise than the previous real-time RTT getting algorithms. We also present the probability analysis which shows that our algorithm has a high matching rate and a high accurate rate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Wireless sensor networks (WSNs) are deployed in numerous mission critical applications in which the network needs to remain active for as long as possible while delivering quality information to a base station. However, WSNs suffer from a wide range of attacks due to their limited processing and energy capabilities. Their resiliency, however, depends on fast recovery from such attacks being achieved. In recent work, the authors developed and implemented clustering, reprogramming and authentication protocols involved in recovering stationary WSNs with low resources. In this paper, we determine the additional resources required in implementing these protocols in a mobile WSN.

We present recovery protocols on TinyOS motes for a low-resourced, mobile deployment. We describe the issues we encountered in the implementation. We present times, RAM and ROM needed to run the recovery protocols and compare these with the stationary case, demonstrating that the additional cost of reprogramming in a mobile WSN is less than 25% of that in a stationary WSN and the additional cost of re-clustering in a mobile WSN is less than 9% of that in a stationary WSN. Authentication has an insignificant cost increase.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The RSA scheme is used to sign messages; however, in order to avoid forgeries, a message can be padded with a fixed string of data P. De Jonge and Chaum showed in 1985 that forgeries can be constructed if the size of P (measured in bytes) is less than the size of N/3, where N is the RSA modulus. Girault and Misarsky then showed in 1997 that forgeries can be constructed if the size of P is less than the size of N/2. In 2001, Brier, Clavier, Coron and Naccache showed that forgeries can still be constructed when the size of P is less than two thirds the size of N. In this paper, we demonstrate that this padding scheme is always insecure; however, the complexity of actually finding a forgery is O(N). We then focus specifically on the next unsettled case, where P is less than 3/4 the size of N and show that finding a forgery is equivalent to solving a set of diophantine equations. While we are not able to solve these equations, this work may lead to a break-through by means of algebraic number theory techniques.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

From diagnosis of life-threatening diseases to detection of biological agents in warfare or terrorist attacks, biosensors are becoming a critical part of modern life. Many recent biosensors have incorporated carbon nanotubes as sensing elements, while a growing body of work has begun to do the same with the emergent nanomaterial graphene, which is effectively an unrolled nanotube. With this widespread use of carbon nanomaterials in biosensors, it is timely to assess how this trend is contributing to the science and applications of biosensors. This Review explores these issues by presenting the latest advances in electrochemical, electrical, and optical biosensors that use carbon nanotubes and graphene, and critically compares the performance of the two carbon allotropes in this application. Ultimately, carbon nanomaterials, although still to meet key challenges in fabrication and handling, have a bright future as biosensors.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Borrowing the title of Raymond Williams’ famous study, the following reflections – sometimes collective and sometimes individual – are based on a series of “Keywords”, specifically: “fear” “community” and “creativity”. By reflecting on the meanings these words have for us today, we attempt to capture their dialogical character, posing them as sites of contestation and struggle, and thereby developing a language of both resistance and hope in the face of neoliberal and neoconservative attacks on education. These reflections continue a series of arguments in defence of the profession first presented in the publication “Only connect”: English teaching, schooling and community in 2006.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Watermarking technique enables to hide an imperceptible watermark into a multimedia content for copyright protection. However, in most conventional watermarking schemes, the watermark is embedded solely by the seller, and both the seller and the buyer know the watermarked copy, which causes unsettled dispute at the phase of arbitration. To solve this problem, many watermarking protocols have been proposed using watermarking scheme in the encrypted domain. In this paper, we firstly discuss many security aspects in the encrypted domain, and then propose a new method of homomorphism conversion for probabilistic public key cryptosystem with homomorphic property. Based on our previous work, a new secure watermarking scheme for watermarking protocol is presented using a new embedding strategy in the encrypted domain. We employ an El Gamal variant cryptosystem with additive homomorphic property to reduce the computing overload of watermark embedding in the encrypted domain, and RA code to improve the robustness of the watermarked image against many moderate attacks after decryption. Security analysis and experiment demonstrate that the secure watermarking scheme is more suitable for implementing the existing watermarking protocols.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 μim in diameter) to smaller size fractions < 2.5 μ (fine particles, PM2.5). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution.

Objective We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air.

Methods We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron -microscopic imaging technique

Results DECP are visualized as small carbon spheres, each 30–60 nm in diameter, forming fractal aggregates about 1–2μ in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p I. binds to one defined class of fine particles, DECP.

Conclusion DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p I under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Making a detour can be advantageous to a migrating bird if fuel-deposition rates at stopover sites along the detour are considerably higher than at stopover sites along a more direct route. One example of an extensive migratory detour is that of the Sharp-tailed Sandpiper (Calidris acuminata), of which large numbers of juveniles are found during fall migration in western Alaska. These birds take a detour of 1500-3400 km from the most direct route between their natal range in northeastern Siberia and nonbreeding areas in Australia. We studied the autumnal fueling rates and fuel loads of 357 Sharp-tailed Sandpipers captured in western Alaska. In early September the birds increased in mass at a rate of only 0.5% of lean body mass day-1. Later in September, the rate of mass increase was about 6% of lean body mass day-1, among the highest values found among similar-sized shorebirds around the world. Some individuals more than doubled their body mass because of fuel deposition, allowing nonstop flight of between 7100 and 9800 km, presumably including a trans-oceanic flight to the southern hemisphere. Our observations indicated that predator attacks were rare in our study area, adding another potential benefit of the detour. We conclude that the most likely reason for the Alaskan detour is that it allows juvenile Sharp-tailed Sandpipers to put on large fuel stores at exceptionally high rates.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The majority of current anonymous systems focus on improving anonymity at the network and website level in order to defend against traffic analysis attacks. However, the vulnerability of the connections between end users and the anonymous network do not attract any attention yet. For the first time, we reveal an end user browsing dynamics based attack on anonymous browsing systems at the LAN where the victim locates. This new attack method is fundamentally different from existing attack methodologies. In general, web surfers browse the web following certain patterns, such as requesting a web page, viewing it and requesting another page. The browsing pattern of a victim can be clearly observed by a local adversary when the victim is viewing the web without protection. Unfortunately, browsing dynamics releases rich information for attacking even though the web page content is encrypted. In order to show how a local eavesdropper can decipher which pages have been viewed with the knowledge of user browsing dynamics and the public information of a given website, we established a specific hidden Markov model to represent browsing dynamics for the website. By using this model, we can then identify the optimal of the accessed pages using the Viterbi algorithm. In order to confirm the effectiveness of the revealed attack method, we have conducted extensive experiments on a real data set. The results demonstrated that the attack accuracy can be more than 80%. A few possible counter-attack strategies are discussed at the end of the paper.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

As an interesting application on cloud computing, content-based image retrieval (CBIR) has attracted a lot of attention, but the focus of previous research work was mainly on improving the retrieval performance rather than addressing security issues such as copyrights and user privacy. With an increase of security attacks in the computer networks, these security issues become critical for CBIR systems. In this paper, we propose a novel two-party watermarking protocol that can resolve the issues regarding user rights and privacy. Unlike the previously published protocols, our protocol does not require the existence of a trusted party. It exhibits three useful features: security against partial watermark removal, security in watermark verification and non-repudiation. In addition, we report an empirical research of CBIR with the security mechanism. The experimental results show that the proposed protocol is practicable and the retrieval performance will not be affected by watermarking query images.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Rapid technological advances have enabled the development of low-cost sensor networks for various monitoring tasks, where it is important to estimate the positions of a number of regular sensor nodes whose locations cannot be known apriori. We address the problem of localizing the regular nodes with range-based location references obtained from certain anchor nodes referred to as beacons, particularly in an adverse environment where some of the beacons may be compromised. We propose an innovative modular solution featuring two lightweight modules that are for dedicated functionalities, respectively, but can also be closely integrated. First, we harness simple geometric triangular rules and an efficient voting technique to enable the attack detection module, which identifies and filters out malicious location references. We then develop a secure localization module that computes and clusters certain reference points, and the position of the concerned regular node is estimated with the centroid of the most valuable reference points identified. Extensive simulations show that our attack detection module can detect compromised beacons effectively, and the secure localization module can subsequently provide a dependable localization service in terms of bounded estimation error. The integrated system turns out to be tolerant of malicious attacks even in highly challenging scenarios.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

With decades of progress toward ubiquitous networks and systems, distributed computing systems have played an increasingly important role in the industry and society. However, not many distributed networks and systems are secure and reliable in the sense of defending against different attacks and tolerating failures automatically, thus guaranteeing properties such as performance, and offering security against intentional threats. This special issue focuses on securing distributed networks and systems.