Cryptography

1 Introduction to Computer Security

Information and computer technologies (ICT), or simply IT technologies, are everywhere, in all fields of activities (business, commerce, transportation systems, health, leisure, education, administration, national security, army, etc.). Nowadays, human beings are more than ever dependent on IT technologies. Therefore, IT security became a paramount concern for any owner or user of electronic devices.

Since the early stage of computers, cyberattacks have never stopped. Worse, statistics provided annually by cybercrime observers and experts often show increases in attacks worldwide. In particular, ransom attacks have become the most lucrative criminal activities in the cyberspace. Partial or total shutdown of systems, as long as ransoms are not paid, results in losses in billions of dollars for companies, hospitals, e-merchants, banks, and individuals.

This chapter aims at providing an introduction to the main issues and notions of security in computer-based systems and tries to answer the following questions:

• What are the security issues and requirements?
• Why and how do security attacks occur?
• How to face security attacks? That is, what are the countermeasures to security attacks?

Security techniques encompass at least two distinct domains:

• Technical domain, including hardware and software design to address security;
• Organizational domain, including education, staff training, and laws to make involved people aware of IT security.

This ...