Computer Network Security

1Fundamentals of Network Security

This chapter studies the following subjects:

• – the chief objectives of securing a network;
• – information security terminology:
  • - general terminology,
  • - types of hackers,
  • - malicious codes;
• – the types of network security:
  • - physical security,
  • - logical security,
  • - administrative security;
• – the chief risks related to the logical security of a network:
  • - the different kinds of network attacks,
  • - measures for network security,
  • - vulnerability audit measures

1.1. Introduction

Network security is the branch of computer science that consists of protecting all components of a computer network in order to prevent unauthorized access, data stealing, misuse of a network connection, modification of data, etc. The aim of network security is to provide proactive defense methods and mechanisms to protect a network against internal and external threats.

1.1.1. The main objectives of securing a network

The three main objectives in securing a network are to ensure:

• – confidentiality: this consists of protecting data stored on or traveling over a computer network from unauthorized persons;
• – integrity: this maintains or ensures the reliability of data. The data received by a recipient must be identical to the data transmitted by the sender;
• – availability: this ensures that network data or services are constantly accessible to users.

1.1.2. Information security terminology

1.1.2.1. General terminology

• – A resource: any object that has value for ...