Summary
Summary

This document contains an overview of the various aspects related to the information and network security. It is divided into eight parts.

The first is an introduction that tries to motivate the reader about the need to protect data and the network communications. Some causes of data and network insecurity are presented along with different basic mechanisms that users should consider in order to protect themselves. Moreover, a basic classification of the types of attacks is included.

The second part is devoted to malicious software and antivirus. Basically, the concept of malicious software is introduced and classified according to several criteria: propagation, installation method, main feature and so on. Furthermore, the chapter describes various techniques for cleaning out an infected computer. Since these techniques require the detection of malware, different strategies commonly used for detection are introduced. Moreover, the document contains basic information on antivirus software, emphasizing the need to keep it updated.

The third part is focused to the security services and mechanisms. The most important security services (confidentiality, integrity, availability, authentication, access control, non-repudiation and privacy) are introduced along with the security mechanisms needed to provide such services. Furthermore, a connection between security services and mechanisms is included.

The fourth part contains basic information about a variety of cryptographic tools used to provide information security. The chapter presents the main differences between symmetric cryptography and public key cryptography, and describes both types of algorithms according to their functionality and performance. Finally, the concept and requirements of a hash function are shown and also it is indicated how these functions are used in digital signatures.

The fifth part is focused to the problem of public key distribution. The concept of digital certificates is introduced as it is the most accepted method to get around this issue. In addition, the problem of certificate revocation is shortly illustrated.

The sixth part includes a short description of two secure protocols (TLS and S/MIME). Both schemes use a combination of public key and symmetric cryptography, and require through the use of digital certificates.

The seventh chapter deals with the perimeter security. The basic components (firewalls and intrusion detection systems) are presented. Moreover, the IDS are classified according to different criteria.

Finally, the eigth part is devoted to the security risks associated with the use of wireless communication networks. Different security solutions have been adopted, although some of them, e.g., the WEP protocol, are vulnerable to a range of attacks. The most accepted solution to ensure the different security requirements in this scenario consists in using the 802.11i standard, also known as WPA2.