Network Security - Research Paper Example

Network security is a complicated procedure but is equally important because it secures the assets of a company and allows it to keep its secretive strategic plans so as to gain competitive advantage. In the contemporary age, as more and more people are networking, network security has become vital for preserving their relationships and making the network beneficial. This paper discusses some of the potential threats to network security and the ways to mitigate them. The paper also renders useful information about network security policing. Information presented in this paper can be used by companies to improve their network security and make the system efficient. Network Security Introduction: Network security is a fairly confusing and complicated subject that has historically been tackled only by experts and experienced professionals. Nonetheless, increased wiring among people in the networked world has increased the need for people to perceive and master the fundamentals of security. This paper has been written with the basic information systems manager and computer user into focus so that they may acquire sufficient knowledge to hype in the market, identify potential threats and to tackle them appropriately. First, a bit of networking history is discussed. This discussion is followed by the introduction to internetworking as well as TCP/IP. Later, risk management, firewalls, and potential network threats will be discussed in order to elaborate the purpose of secure networking tools and devices. This paper is intended to lend the audience a broad perspective of the network security in general, and a sense to identify, manage and reduce risks both at home and the workplace in particular. In order to sufficiently comprehend the rules and traits of network security, it is imperative that an individual has some basic knowledge of computer networks. Therefore, it is customary to briefly discuss the foundations of computer networking before moving over to the popular networks and their security. What is a Network? A network may be defined as a set in which lines that resemble a net interlink with one another. It is essentially a system of interconnected lines. Like any network, a network of computer essentially has many computers interlinked with one another. There are numerous ways to interconnect the computers. There are seven layers of communications types with interfaces according to the Reference Model of the International Standards Organization (ISO) / Open Systems Interconnect (OSI) as shown in the figure below: “The ISO/OSI Reference Model” (Curtin, 1997). Each layer is dependent upon the services of the immediately lower layer. This pattern follows until one gets on the lowest layer of physical network. This can be best understood by drawing a comparison between this model and something of everyday use like a telephone. A telephone is the means of transmittal of message between two people when they are sufficiently away to be out of each other’s earshot. Same happens at the application layer of the ISO/OSI model. The telephones serve the purpose by converting the sound into electronic pulses which may be transmitted back and forth through the wire. Layers underneath the application layer serve the very purpose. Both sets of the telephone need to be connected into a switch which is an essential component of the network of switches of the telephone system. In order to make a call, an individual needs to pick the receiver up and dial the desired extension or number. This number indicates the central office which the request goes to so that a phone from that office rings up. The individual at the other end picks up the receiver and the conversation begins. Computer networks have a similar way to function. Some Popular Networks: A lot of networks have been identified and employed over the last 2.5 decades or more. In this paper, two of them will be looked into. Both of the networks are public networks, that essentially means that either of them can be connected by anyone. People can also use different kinds of networks in order to connect their respective computers with one another without having to make use of the public networks. Different types use alternate approaches to provide the network services. The Unix-to-Unix CoPy (UUCP) originally connected different Unix hosts with one another. Since its formulation, UUCP has been ported to various architectures like Apple IIs, PCs, VMS hosts, and Amigas. Many systems have been formulated on the pattern of UUCP. All such systems are batch oriented i.e. their activities add up in a line which keep being processed from time to time. Dial-up connections are usually used to build up the UUCP networks. However, it is quite possible to use UUCP over any connection between some computers in the availability of internet. The Internet: Internet happens to be the biggest network of all networks in the world. When an individual tends to visit the web pages, he/she essentially gets connected to a network which is ultimately linked with the backbone of internet. It is important to realize that internet is not where hosts link with one another. Internet is rather a network of many more networks. Construction of a simple network is possible by means of using same protocols in a way that allows the use of internet without connection with anything. The following figure shows such a basic network: “Simple Local Area Network” (Curtin, 1997). TCP/IP: TCP/IP is internet’s language and is the abbreviation for Transport Control Protocol / Internet Protocol. Anything that knows this language can operate the internet. In the Reference Model of the ISO/OSI, this functionality happens on the layers of Network and Transport. A very important characteristic of TCP/IP is that its protocol is open for anyone. Scientists participate in Internet Engineering Task Force (IETF) from all over the world with a view to designing protocols to help internet function. IP enables hosts to communicate with one another. Why is Network Security Important? According to Canavan (2001), network security is important because of four fundamental reasons which are stated below: 1. It protects the assets of a company. 2. It provides companies with an opportunity to gain competitive advantage. 3. It helps companies comply with the requirements of law. 4. It helps people keep their job. Network Security Policy: Experts of the network security mutually consent upon the opinion that corporations should have their own individualistic security policies. The security policy establishes expectations about both the administration and use of the assets of corporate IT. “However, the conventional wisdom holds that composing and maintaining these documents bog down in a morass of bureaucratic inefficiency and pointless wrangling, which never ends and produces nothing useful” (Avolio and Fallin, 2007, p. 2). Most corporations only need in-house knowledge in order to be able to draft, modify and implement a network security policy. It is very rare of an organization to be content with the security policy and many do not have any at hand, though all organizations follow some sort of security policy that can be informal or formal. A vast majority of the network security policies are simply insufficient and ineffective. Seldom has an organization maintained an effective network security policy. In order for the security policy to be effective, it is imperative that it remains same, relevant and applicable at all times. Misconceptions regarding Network Security Policing: According to Avolio and Fallin (2007, p. 2-3), there are four common types of misconceptions that keep the corporations from developing rational policies. They are as follows: 1. Network security aims at making the network secure. Although securing the network is easy, though it is hardly ever the goal. The real goal of a corporation is indeed securing the whole business. Network security aims at supporting the network and requirements of the computer business and making use of such methods that would reduce the risk. 2. It is compulsory for the security policies to be complex and lengthy. In reality, truth is opposite to this. The simpler the system, the more secure it is. A good network security policy comprises a whole set of documents each of which fulfill a particular need. The network security policy should not only be easily perceivable, readable and memorable, but it should also fully reflect the corporate culture. 3. Security policies need to be 100 per cent complete and almost perfect. That is not true! Sufficiently good security today is far better than perfect security which is yet to materialize. Organizations normally deal security like a sacred thing when they should actually adopt an increasingly practical approach. A security policy can be written rightly in several ways. All good policies always have room for modification and improvement. 4. Security policies are written once and for all. Management and modification of a network security policy is a never-ending process. With the passage of time, an organization is exposed to newer threats. Along with them, the requirements of business change as well. Risks and the ways to mitigate them all keep changing. Therefore, the network security policy can also not be standardized and unalterable. Firewalls Inhibiting Innovation: “The firewall acts as a packet filter, examining all IP packets and passing only those meeting specific criteria, such as destination, or running specific transport protocols (like TCP), or supporting specific applications” (Messerschmitt, 1999, p. 2). It is extremely important to note that there is no best firewall to ensure the security of a network. In fact, absolute access and absolute security are two extremes. A machine can be provided with maximum security only by disconnecting it from the network and locking it somewhere which totally saps its usability. A machine that has absolute access is the most convenient in use. It will do as directed without any inquiry which is also not practical. “…the Internet is a bad neighborhood now, and it isn't long before some bonehead will tell the computer to do something like self-destruct, after which, it isn't terribly useful to you” (Curtin, 1997). All organizations need to decide their location between the two extremes of total access and total security. This is articulated by a policy which essentially suggests the ways to enforce the decision thus taken. Thus, everything that makes part of the security must allow a uniform implementation and follow-up of policy. Common Sources of Risks: The potential sources of risks commonly encountered are as follows: Denial-of-Service (DoS): These attacks are generally considered as the nastiest attacks among all in that addressing them is the most difficult task and yet, they can be launched most easily. They are often impossible to track. Most of the times, requests of the attacker can not be refused or the legitimate requests for service would also be refused. The DoS attack has a fairly simple premise, i.e. the machine needs to be sent more requests than its capacity to handle. Toolkits from the underground community allow this to run a program and choose the host to bombard with requests. These attacks were frequently encountered in the late 1996 and early 1997, though they have decreased in popularity today. Measures to avoid DoS include, avoiding operating the servers too close to their capacity and remaining updated on the security-related patches for the operating systems of the host. Unauthorized Access: Different kinds of attacks are covered by the umbrella term of “unauthorized access”. These attacks are directed at accessing resource which the machine must avoid giving to the attacker. A host like a web server allows anyone to access web pages, though, the host should make sure that the person demanding the information is either local administrator or an individual authorized by him/her. Executing Commands Illicitly: The last thing a computer owner would like to see would be an untrustworthy individual able to execute commands on his/her computer. This problem can be severe in two ways, namely the administrator access and the normal user access. a normal user can read files and forward them. An attacker must be disallowed from doing this. An attacker might as well want to make configuration changes like altering the host’s IP address in which case, he/she will be required to attain administrator privileges on host. How to Protect the Host? Access control as well as the authentification of users associated with it is a potential way to protect a host. Some of the most commonly employed authentification approaches are not secure enough. Users are commonly asked to provide a password that can as well be caught in transit till the encryption of the entire session. In other cases, it is authenticated with the help of the IP address of the host. When some one intrudes into the system and somehow gains access to the network, it becomes possible for him/her to monitor the network traffic. A lot of valuable information can be uncovered by such a sniffing attack including the IP address of user passwords or the host. “It is possible for an attacker to masquerade as a differed host by spoofing an IP address, making it appear that packets are originating from another host” (Messerschmitt, 1999, p. 1). Free / Open Source Software (FOSS): One of the biggest examples of the successful implementation of free softwares is internet which happens to be the largest network. IP protocol is the basis of internet. FOSS has helped internet become a reliable network (Upadhaya, 2007, p. 7). However, FOSS has certain limitations like most of it conforms to the open processes and their standards. Some propriety processes and softwares have no FOSS equivalent. Propriety softwares may occasionally be used to access hardware. The rapid pace of FOSS development may also be quite confusing for some users, though it comes as an advantage for the providers of the service. References: Avolio, F. M., and Fallin, S. (2007). Producing Your Network Security Policy. Retrieved from http://www.watchguard.com/docs/whitepaper/securitypolicy_wp.pdf. Canavan, J. E. (2001). Fundamentals of Network Security. UK: Artech House Inc. Curtin, M. (1997). Introduction to Network Security. Retrieved from http://www.interhack.net/pubs/network-security/. Messerschmitt. D. G. (1999). Network Security. University of California. Retrieved from http://www.eecs.berkeley.edu/~messer/netappc/Supplements/19-netsec.pdf. Upadhaya, G. R. (2007). Free/Open Source Software: Network Infrastructure and Security. 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