Anomaly Based Intrusion Detection System Essays

Anomaly Based Intrusion Detection System Essays Anomaly Based Intrusion Detection System Paper Anomaly Based Intrusion Detection System Paper Intrusion detection solved. This paper begins with a review of the most well-known anomaly- based intrusion Anomaly detection detection techniques. Then, available platforms, systems under development and research IDS systems and platforms projects in the area are presented. Finally, we outline the main challenges to be dealt with Assessment for the wide scale deployment of anomaly-based intrusion detectors, with special emphasis on assessment issues. A 2008 Elsevier Ltd. All rights reserved. Introduction Intrusion Detection Systems (IDS) are security tools that, like other measures such as antivirus software, firewalls and access control schemes, are intended to strengthen the security Of information and communication systems. Although, as shown in Kabuki and Giordano (2005) and Sobs (2006), several IDS approaches have been proposed in the specialized literature since the origins of this technology, two highly relevant works in this direction are Dinning (1987) and Stanford-Chem. et al. (1998). Noteworthy work has been carried out by CDC (Common Intrusion Detection Framework), a working group created by DARPA in 1 998 mainly oriented towards coordinating and defining a common framework in the IDS field. Integrated thin IETF in 2000, and having adopted the new acronym IDS (Intrusion Detection Working Group), the group defined a general IDS architecture based on the consideration of four types of functional modules (Fig. L): E blocks C Event-boxes): This kind of block is composed of sensor elements that monitor the target system, thus acquiring information events to be analyzed by other blocks. D blocks (Database-boxes): These are elements intended to store information from E blocks for subsequent processing by A and R boxes. A blocks (Analysis-boxes): Processing modules for analyzing events and detecting potential hostile behavior, so that some kind of alarm will be generated if necessary. * Corresponding author. Department of Signal Theory, Telemetric and Communications - ? Computer Science and Telecommunications Faculty, University of Granddad, C/ Periodical Daniel Sauced Rand, 18071 Granddad, Spain. Tell. : 958242305; fax: 958240831. E-mail addresses: [emailprotected] SE (P. Garcia a-Terror), [emailprotected] SE (J. Del AZ-Overdue), [emailprotected] SE (G. Maniac -Fern need), [emailprotected] did. Mum. SE (E. Va squeeze). 0167-4048/$ -? see front matter a 2008 Elsevier Ltd. All rights reserved. Did:1 0. 016/j. cosec. 2008. 08. 003 19 A-box E-box D-box R;box Fig. 1 General CEDE architecture for IDS systems. R blocks Correspond-boxes): The main function of this type of block is the execution, if any intrusion occurs, of a response to thwart the detected menace. Other key contributions in the IDS field concern the definition of protocols for data exchange between components (e. G. IDS, Intrusion Detection exchange Protocol, RFC 4767), and the format considered for this (e. G. TIMED, Intrusion Detection MEssage Format, RFC 4765). Depending on the information source considered (E boxes in Fig. ), an IDS may be either host or network-based. A hostesses IDS analyzes events such as process identifiers and system calls, mainly related to SO information. On the other hand, a network-based IDS analyzes network related events: traffic volume, IP addresses, service ports, protocol usage, etc. This paper focuses on the latter type of IDS. Depending on the type of analysis carried out (A blocks in Fig. ), intrusion detection systems are classified as either signature-based or anomaly-based. Signature-based schemes (also denoted as misuse-based) seek defined patterns, or signatures, within the analyzed data. For this purpose, a signature database corresponding to known attacks is specified a priori. On the other hand, anomaly-based detectors attempt to estimate the normal behavior of the system to be protected, and generate an anomaly alarm whenever the deviation between a given observation at an instant and the normal behavior exceeds a predefined threshold. Another possibility is to model the abnormal behavior of the system and to raise an alarm when the difference between the observed behavior and the expected one falls below a given limit. Signature and anomaly-based systems are similar in terms f conceptual operation and composition. The main differences between these methodologies are inherent in the concepts of attack and anomaly. An attack can be defined as a sequence of operations that puts the security of a system at risk. An anomaly is just an event that is suspicious from the perspective of security. Based on this distinction, the main advantages and disadvantages of each IDS type can be pointed out. Signature-based schemes provide very good detection results for specified, well-known attacks. However, they are not capable of detecting new, unfamiliar intrusions, even if they are built as minimum Arians of already known attacks. On the contrary, the main benefit of anomaly-based detection techniques is their potential to detect previously unseen intrusion events. However, and despite the likely inaccuracy 2. A-NDIS techniques Although different A-NDIS approaches exist (Est. postoperative et al. , 2004), in general terms all of them consist of the following basic modules or stages (Fig. 2): Parameterization: In this stage, the observed instances of the target system are represented in a pre-established form. Training stage: The normal (or abnormal) behavior of the yester is characterized and a corresponding model is built. This can be done in very different ways, automatically or manually, depending on the type of A-NDIS considered (see classification below). Detection stage: Once the model for the system is available, it is compared with the (parameterized) observed traffic. If the deviation found exceeds (or is below, in the case of abnormality models) a given threshold an alarm will be triggered (Est. ;fez-Topiary et al. , 2004). According to the type of processing related to the behavioral model of the target system, anomaly Parameterization n formal signature specifications, the ra te of false positives (or UP, events erroneously classified as attacks; see Section 2) in anomaly-based systems is usually higher than in signatures ones. Given the promising capabilities of anomaly-based network intrusion detection systems (A-NDIS), this approach is currently a principal focus of research and development in the field of intrusion detection. Various systems with A-NDIS capabilities are becoming available, and many new schemes are being explored. However, the subject is far from mature and key issues remain to be solved before wide scale deployment of A-NDIS littorals can be practicable. Focusing, thus, on A-NDIS technologies, the rest of this paper is organized as follows: Section 2 presents the various algorithms proposed for anomaly detection. Then, existing A-NDIS platforms, either currently available or under development, and which include anomaly detection functionalities, are presented in Section 3. This constitutes a valuable contribution of the present paper in comparison with other published work. The fourth section discusses open issues and challenges in this field, with special emphasis on A-NDIS assessment. Finally, Section 5 summarizes the main mints of the paper. Monitored environment Training Model Detection Intrusion report Fig. 2 Generic A-NDIS functional architecture. 0 detection techniques can be classified into three main categories (Lacerative et al. , 2005) (see Fig. 3): statistically, knowledge- based, and machine learning-based. In the statistical-based case, the behavior of the system is represented from a random viewpoint. On the other hand, knowledge-based A-NDIS technique uses try to capture the claimed behavior from available system data (protocol specifications, network traffic instances, etc. ). Finally, aching learning A-NDIS schemes are based on the establishment of an explicit or implicit model that allows the patterns analyzed to be categorized. Two key aspects concern the evaluation, and thus the comparison, of the performance of alternative intrusion detection approaches: these are the efficiency of the detection process, and the cost involved in the operation. Without underestimating the importance of the cost, at this point the efficiency aspect must be emphasized. Four situations exist in this context, corresponding to the relation between the result of the detection for an analyzed event (normal vs.. Intrusion) and its actual nature (innocuous vs.. malicious). These situations are: false positive (UP), if the analyzed event is innocuous (or clean) from the perspective of security, but it is classified as malicious; true positive (HTTP), if the analyzed event is correctly classified as intrusion/malicious; false negative (FAN), if the analyzed event is malicious but it is classified A. L) A) Statistical based Multivariate Time series model 8. 1) B) Knowledge based 8. 2) 8. 3) c. 3) C) Machine learning based inebriate c. 5) c. 6) FSML Description languages Expert systems Bayesian networks Markova models Neural networks Fuzzy logic Genetic algorithms Clustering outlier detection Fig. 3 Classification of the anomaly detection techniques according to the nature of the processing involved in the behavioral model considered. As normal/innocuous; and true negative (TN), if the analyzed event is correctly classified as normal/innocuous. It is clear that low UP and FAN rates, together with high HTTP and TN rates, will result in good efficiency values. The fundamentals for statistical, knowledge and machine learning-based A-NDIS, as well as the principal subtypes of each, are described below. The main features of all are unmarried in Table 1 . Above and beyond other possibilities, the question of efficiency should be a prime consideration in selecting and implementing A- NDIS methodologies. 2. 1. Statistical-based A-NDIS techniques In statistical-based techniques, the network traffic activity is captured and a profile representing its stochastic behavior is created. This profile is based on metrics such as the traffic rate, the number of packets for each protocol, the rate of connections, the number of different IP addresses, etc. Two datasets of network traffic are considered during the anomaly detection process: one responds to the currently observed profile over time, and the other is for the previously trained statistical profile. As the network events occur, the current profile is determined and an anomaly score estimated by comparison Of the two behaviors. The score normally indicates the degree of irregularity for a specific event, such that the intrusion detection system will flag the occurrence of an anomaly when the score surpasses a certain threshold. The earliest statistical approaches, both network oriented and host oriented IDS, corresponded to inebriate models, which modeled the parameters as independent Gaussian madman variables (Dinning and Neumann, 1985), thus defining an acceptable range of values for every variable. Later, multivariate models that consider the correlations between two or more metrics were proposed (Ye et al. , 2002). These are useful because experimental data have shown that a better level of discrimination can be obtained from combinations of related measures rather than individually. Other studies have considered time series models (Detecting Hackers), which use an interval timer, together with an event counter or resource measure, and take into account the order and the enter-arrival times of the observations as well as their values. Thus, an observed traffic instance will be labeled as abnormal if its probability of occurrence is too low at a given time. Apart from their inherent features for use as unemployable techniques, statistical A-NDIS approaches have a number of virtues. Firstly, they do not require prior knowledge about the normal activity of the target system; instead, they have the ability to learn the expected behavior of the system from observations. Secondly, statistical methods can provide accurate notification of malicious activities occurring over long roods of time. However, some drawbacks should also be pointed out. First, this kind of A-NDIS is susceptible to be trained by an attacker in such a way that the network traffic generated during the attack is considered as normal. Second, setting the values of the different parameters/metrics is a difficult task, especially because the balance between false positives and false negatives is affected. Moreover, a statistical distribution per variable is assumed, but not all behaviors can be 21 Table 1 Fundamentals of the A-NDIS techniques Technique: basics A) Statistical-based: autistic behavior B) Knowledge-based: availability of prior knowledge/data C) Mach nine learning-based: categorization of patterns Pros Cons Us Betsey Prior knowledge about normal activity not required.

Tragic flaw Essays

Tragic flaw Essays Tragic flaw Paper Tragic flaw Paper To what extent is the Summer Song sequence, sung by the narrator, a watershed in the play Blood Brothers? The three main themes of Willy Russells Blood Brothers are superstition, fate and class divides. These themes are overtly represented throughout the play. Because the play opens with a scene of the two dead boys there is a constant dramatic irony to all actions in the play; this inevitable tragedy undermines all the happiness in an ironic way. Near the start of the play, the deaths are only suggestions in the boys futures, but as the play develops the themes become more evident, eventually Summer Song is the turning point, the point of no return, the point where everything is as good as it gets. Russell gives the play a very clear and simple structure. The audience knows they are to sympathise with Mrs Johnstone. Not only is she a single mother, she is poor and working class too. Her character is the most developed and given more stage time and songs. Foreshadowing is a very important component of the plays structure. During the childrens game with toy guns, Mickey says, I dont want to die. He is subconsciously appealing to the devil to change his fate. We begin to pity Mickey because he is so defenceless and weak. The narrator creates tension and a feeling of inevitability by using phrases such as hes gonna find y' He is often depicted as Fate, appearing before and after important events, sometimes during, as if to pinpoint the moment, such as when Mrs Johnstone must swear on the bible that she will give away her baby. His snide and often ironic comments about the mothers are generally ambiguous and could apply to either mother (An did y never hear of the mother so cruel. ) The audience is told to come to their own decisions about the mothers (come judge for yourselves. ) The narrator creates tension, always hovering in the background, almost omnipresent, even wearing funeral clothes. He is like a vulture circling above the twins, waiting for their inevitable deaths. His constant presence on stage and in the script keeps the ominous tones going. As they get older, he appears more often, worrying and reminding you that the twins death is coming closer. The Summer Song is when the boys pass the middle of their lives, the peak of the mountain, and begin to accelerate downwards with an unstoppable chain of events leading to their certain deaths. The boys envy each other, I wish I was a bit like That guy, and events occurring to either of them are usually echoed or mirrored by the other. As children, Mickey is seen as the lucky one in the game of life, while Edward seems destined to watch from the sidelines. However, after the Summer Song, once the boys are adults, there is no time for laughter, the game has ended, and Mickey can no longer play and must now work. Edwards lifestyle becomes the ideal, which angers Mickey. Blood Brothers is structured like a Greek tragedy, using death as a spectacle, one main plot and a sad ending. It has a clear time frame, songs and music and, most importantly, a tragic hero (Mickey), someone who falls from grace due to their tragic flaw. Most events are mirrored, for example the childrens game with toy guns(I shot y), to Sammys air rifle(he produces an air rifle), to the gun at the fair, to the gun Sammy uses to shoot someone(an explosion from the gun), to the gun Mickey kills Edward with (the gun explodes and blows Edward apart). Before the Summer Song the guns are either imaginary or toys, safe and harmless. However, afterwards, they are still used as freely as the pretend guns, but take real lives. References to Marilyn Monroe are constant. Like bright young things, like Marilyn Monroe. Dreams all night of girls that look like Marilyn Monroe. In the first song (Marilyn Monroe) Marilyn Monroe is a symbol of youth and beauty, but throughout she changes into one of tragedy, referring to her drug taking and consequential death, which coincides with Mickeys addiction to his anti-depressants. Sexier than Marilyn Monroe to off the rails, treats his ills with daily pills, he was dead, Like Marilyn Monroe The childrens game is echoed after the Summer Song. In the first half I got y, I shot y, An y bloody know I did, And in the second, You shot him, you shot him. I know I bloody did. This is a conversation between Mickey and Sammy, his older brother.

Are maritime transportation loosing out its competitive advantage over Essay

Are maritime transportation loosing out its competitive advantage over other modes of transportation like air and road transportation Justify your views - Essay Example The existence of maritime routes or in other words the fact that regular itineraries are existent is said to be the concept of maritime transportation.1 There have been quite a few technological transformation which have had the potential of affecting water transports, the most recent one is that of the modification of water canals, increasing the size as well as the automation and specialization of vessels. However it has been noted that the increase in maritime traffic has had the consequences of major ecological disasters.2 It needs to be pointed that the bulk of circulation that takes place through maritime transportation is limited along coast line and further three continents have limited fluvial trade. The majority of maritime infrastructure requires a huge maintenance cost for the modification of waterways or investments on the expansion of capacities of ports, which is very expensive and on the other hand takes a lot of space.3 It needs to be pointed out at this point that not every country has direct access to the ocean, these countries are better known as the maritime enclave that is they have difficulties in undertaking maritime trade since they are not part of what is called the domain of maritime circulation. So it requires agreements between neighboring countries to have access to the facilities of port via road, rail line or any other possible alternative. It is important to keep in mind that the countries which are enclave are not excluded from international trade or in other words it can not be implied that they can not take part in international trade, but the problem that they face are that they face higher costs which might lead to weakening of economic development.4 It has been proved that due to the establishment of commercial linkage between continents, maritime transport has been able to sustain a substantial amount of traffic which covers approximately 90% of intercontinental transport demand of

Cost Management and Activity-Based Costing Essay

Cost Management and Activity-Based Costing - Essay Example This case is built upon the cutting most of the things and leaving only those which are absolutely necessary for the company like firing of both secretaries, the firing of one secretary, one social worker for Community Mental Health Services and one Social Worker for Outpatient mental health treatment, cutting in half the purchased services of security and consultation and the replacement of an assistant on lower pay rate. Reducing budgets are a very difficult job for the administration. Whosever share gets cut, that person becomes unhappy which may lead to future disagreements or problems. For this reason the management has to sort out the budget cuts from appropriate angles and has to deal with the problems straight on. The budgets cuts that can be reduced in this budget are prioritized below one by one. As mentioned before, budgets must be properly handled when there is a need to reduce them or great problems can occur. The first step to reduce the budget is to review the program and management achievements and fiscal performance over the year. This includes reviewing the objectives achieved, comparing budget to actual figures, and looking at the number of people served in each program. Based on this review, new goals and objectives should be discussed and agreed upon in a preliminary way. These goals must be realistic in nature sticking to the fact that the budget will be reduced and the targets would be harder to achieve. To reduce expenses, it is helpful to determine what each program would cost at different service levels. A fixed percent cut across all expense lines is often not the most effective way to reduce expenses. For instance, do not assume that benefits and costs move together, with each additional dollar spent resulting in an additional dollar of results. The costs to reduce must be properly analyzed first and then the reduction must be implemented. The estimate of the costs required in achieving the objectives,

Disagreements about the ideals of management will always exist. But Essay

Disagreements about the ideals of management will always exist. But the realities of management can be established on the basis of evidence, rather than ideas about what they ought to be - Essay Example Management facilitates the production of desired and useful outcomes in the system of organization. However, management faces many disagreements about its ideals which always exist. However, management realities can be established on basis of evidence, instead of what they ought to be. Managers are the business drivers of an organisations goals and objectives, so as to realise its realities. Therefore, management has many challenges that result into conflicts. Fortunately, if these conflicts can be solved on the basis of evidence, they can be turned into great opportunities for the business, rather than ideas of what they would have been (Pruitt, 1983). Hence, a skilled manager will always seek to turn challenges into opportunities by basing his decisions and actions on evidence. This essay looks into the disagreements that exist in business, how management realities can be established on the basis of evidence rather than ideas about what they ought to be. Some of the issues raised in the statement are what the disagreements and their causes, what are the management realities and what evidence are required. In the past, management was looked at from the functional perspective, which is, regularly measuring a quantity and undertaking necessary adjustments of the initial plans in order to attain the desired goals, even without planning. One of the greatest contributor of modern management concepts, Henri Fayol (1841-1925, pg, 23) however considers management functions as planning, forecasting, coordinating, commanding, and organizing the activities of a business. However, Mary Follet (1869-1933) describes management as the philosophy of having things done by other people (Gomez-Mejia, 2008, pg 19). The difficulties of defining management, changing nature in its definitions, and difficulties of connecting managerial practices with the class or cadre of management shows how critical and difficult management task involve, since they finally dictate the well being

English Composition Essay Example for Free

English Composition Essay In the aspect of writing English composition, several rules and guidelines must be followed for the aspect of clarity, clearness, and understandability. This grammar rules are established to follow a clear and concise presentation of the ideas and concepts being communicated in each composition. Included in these guidelines and rules is the use of examples and how they are used to promote the main argument in each composition. In the use of examples in the English composition, several approaches are established to guide the use of this strategy for the clearness in the composition. First, is using example in a word or phrase employing short approaches towards the presentation. The second is through sentence-length examples, which are more specific as they employ the idea along with the specific example explaining the said concept. Third is through the use of extended examples, which are commonly to be an entire paragraph for more detailed explanation and presentation. For better composition, most writer use different styles and conjoined different approaches in a single essay for more detailed explanation of the main topic. For example, in the composition of John Head entitled â€Å"The Brutal Business of Boxing†, the author was able to clearly and specifically presents his topic and ideas through the use of both single word or phrase example and sentence-length examples. In most paragraphs, the author mentioned specific words to support his topic and in the others, he used the sentence-length examples, which includes the idea and the specific argument explaining the concept. Through this approach, the author has able to present clearly his main argument and reasons about his opinions towards the brutal nature of boxing explaining why the said act should be condone not as a sport but as an uncivilized fight in the society.

Leonardo Da Vinci :: Visual Arts Paintings Art

Leonardo Da Vinci Leonardo Da Vinci is a world renowned Italian painter, sculptor, architect, musician, engineer, and scientist. His curiosity for the things around him and the research was the fundamental point of his artistic and scientific accomplishments. His creations in painting influenced Italian art centuries after his death and his scientific studies (anatomy, optics and hydraulics) have helped made many developments of modern science. His famous paintings for example the Mona Lisa and the Last Supper are known world wide. People crave to own his paintings, or even just to have a look at them; Leonardo had influenced everyone up to this present day. Even Bill Gates used $30 million US for Leonardo’s painting ‘Codex Leicester’! Who is this remarkable man? And what did he do that taught the world to look at art and science in a new perspective? Leonardo told us that he was born on April 15th 1952 in the city of Vinci in Italy and was the son of a notary and a peasant girl. His parents had a lot of kids, but not with each other and having him ending up with 17 half sisters and brothers. He said that living in Vinci was the place where he developed his creativity and interest in nature. He was also exposed to the ancient Vinci painting tradition at that time. In 1466, he moved to Florence where he was apprenticed in the famous workshop of ‘Andrea Del Verrochio’. While working there, he painted an angel in Verrochio’s ‘Baptist of Christ’. His painting was so much better than his master that Verrochio never painted again. In 1482, Leonardo wrote a letter to the Duke of Milan telling him that he could build portable bridges that would enable dry routes for people to travel. At this time, he carried notebooks and started to keep all his ideas, opinions on everything including domestic, personal, scientific and philosophical along with explanatory sketches. These notebooks were full of advice for science and art not only for the people in the Renaissance but also useful painters now. The Duke gave lots of jobs to him that included designing weapons, buildings and machinery. He produced lots of ideas for nature, flying machines, geometry and mechanical things. His eager to start new things made it hard for him to complete the things that he had started making him only completing 6 of 17 works that he had done. He started to find himself interested in painting, architecture, the elements of mechanics and human anatomy from 1490 to 1495. He spent this time studying science or locking himself up in his room