- Current section: Introduction
- Learning Outcomes
- 1 Terminology and abbreviations
- 2 Background to network security
- 3 Threats to communication networks
- 4 Principles of encryption
- 5 Implementing encryption in networks
- 6 Integrity
- 7 Freshness
- 8 Authentication
- 9 Access control
- 10 Summary
- Module team
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Encryption of files and firewalls are just some of the security measures that can be...
Encryption of files and firewalls are just some of the security measures that can be used in security. This unit, which assumes you have a substantial knowledge of computing, helps to explain the intricacies of the continually changing area of network security by studying the main issues involved in achieving a reasonable degree of resilience against attacks.
Ideally, after studying this unit you should be able to apply the material appropriately in unfamiliar circumstances. In particular, you should be able to describe some threats to the security of communication networks and some of the countermeasures employed. The following learning outcomes are an indication of the level of knowledge you should have. You should be able to:
- Identify some of the factors driving the need for network security.
- Identify and classify particular examples of attacks.
- Define the terms vulnerability, threat and attack.
- Identify physical points of vulnerability in simple networks.
- Compare and contrast symmetric and asymmetric encryption systems and their vulnerability to attack, and explain the characteristics of hybrid systems.
- Explain the implications of implementing encryption at different levels of the OSI reference model.
- Explain what is meant by data integrity and give reasons for its importance.
- Describe methods of providing assurances about data integrity.
- Describe the use of hash functions and explain the characteristics of one-way and collision-free functions.
- Describe and distinguish between different mechanisms to assure the freshness of a message.
- Explain the role of third-party agents in the provision of authentication services.
- Discuss the effectiveness of passwords in access control and the influence of human behaviour.
- Identify types of firewall implementation suitable for differing security requirements.
- Apply and explain simple filtering rules based on IP and TCP header information.
- Distinguish between firewalls based on packet-filtering routers, application level gateways and circuit level gateways.
Communication networks are used to transfer valuable and confidential information for a variety of purposes. As a consequence, they attract the attention of people who intend to steal or misuse information, or to disrupt or destroy the systems storing or communicating it. In this unit you will study some of the main issues involved in achieving a reasonable degree of resilience against network attacks. Some attacks are planned and specifically targeted, whereas others may be opportunistic, resulting from eavesdropping activities.
Threats to network security are continually changing as vulnerabilities in both established and newly introduced systems are discovered, and solutions to counter those threats are needed. Studying this unit should give you an insight into the more enduring principles of network security rather than detailed accounts of current solutions.
The aims of this unit are to describe some factors that affect the security of networks and data communications, and their implications for users; and to introduce some basic types of security service and their components, and indicate how these are applied in networks.
This unit is from our archive and is an adapted extract from Multi-service networks: controls (T823) which is no longer taught by The Open University. If you want to study formally with us, you may wish to explore other courses we offer in.
This is an extract from an Open University course which is no longer available to new students. If you found this interesting you could explore more free Systems (Computer) course units or view the range of currently available OU Systems (Computer) courses.
Copyright & revisions
Originally published: Tuesday, 19th July 2011
- Creative-Commons: The Open University is proud to release this free course under a Creative Commons licence. However, any third-party materials featured within it are used with permission and are not ours to give away. These materials are not subject to the Creative Commons licence. See terms and conditions. Full details can be found in the Acknowledgements section.
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