Before starting the SCU202 course, I'd like to briefly review the fundamental concepts covered in the previous course("SCU101") in this chapter.

Moreover, if you're still a computer beginner and haven't taken SCU101, I strongly recommend starting with that first course before moving on to this one. The basics covered in SCU101 will not be repeated here. I will therefore not return to basic security practices, nor on the use of VPNs, password managers, or two-factor authentication. And yet, all these concepts are essential to master before moving on to more advanced uses, which we'll cover in the following chapters.

The SCU101 course was an introductory course designed to establish a solid base in digital hygiene for beginner and intermediate users in IT. Its aim was to improve daily security, privacy and digital sovereignty.

Internet browsing is often the main entry point for cybersecurity threats. In SCU101, we saw that it is important to stay vigilant, especially when it comes to downloads. Download only files from reliable sources, and prefer open-source software, which often benefits from greater transparency and community control.

Another good practice covered in the course involved cookies, those little files stored on your computer when you visit websites. You should regularly delete or limit them to protect your privacy.

Generally speaking, secure browsing requires a certain amount of caution: avoid clicking on unknown links, avoid suspicious sites, and use a secure, up-to-date browser.

SCU101 introduced you to the concept of a VPN (Virtual Private Network). In practical terms, a VPN encrypts your internet traffic by creating a secure tunnel between your device and a remote server. However, not all VPNs are the same: prioritize transparent, reliable providers that allow anonymous signup, such as Mullvad, ProtonVPN or IVPN. These VPNs ensure you optimal privacy without collecting your personal data unnecessarily.

Moreover, we had seen that on public Wi-Fi networks, the connection is particularly exposed. That's why using a VPN is essential. If you can't use one, connect only to HTTPS sites to protect your data exchanges.

Security also means knowing your operating system (OS). You've explored the three main OSes: Windows, macOS and Linux, each with its own security features. On Windows especially, an up-to-date antivirus is essential to detect and block malware.

SCU101 also warned you to never plug in unknown USB drives into your computer, as they may contain malware that could infect your system.

An essential part of SCU101 training was understanding cyber attacks. Viruses don't just appear on their own: they usually require your unintentional intervention, such as downloading an infected file or opening a fraudulent link in an e-mail.

One of the most common attacks is phishing, in which fraudulent messages are sent to encourage you to disclose sensitive data. When facing these attacks, systematically check the sender, and avoid clicking on links or opening attachments from unknown or suspicious sources.

Another major threat is ransomware, which blocks your data by encrypting it and demanding a ransom. To deal with this, regular backup of your data is essential.

SCU101 particularly emphasized the importance of securing your e-mail, the gateway to all your other online accounts. A compromised mailbox allows the hackers to reset the passwords of almost all your accounts via the usual e-mail recovery procedures.

So you've seen the importance of creating secure, dedicated e-mail addresses. It is wise to have a specific e-mail address reserved for account recovery, separate from your main address.

Digital security heavily relies on the quality of your passwords. SCU101 explained why using a password manager is essential: these tools enable you to generate and store complex, unique and random passwords for each service you use.

Password managers greatly simplify the task for you, since you only have to remember one master password for all the others.

Finally, SCU101 introduced you to two-factor authentication (2FA). The principle consists of performing authentication in two separate steps: your usual password and a second factor, like a temporary code generated by an application like Google Authenticator or Authy, or a hardware key like YubiKey.

2FA protects your accounts considerably better: even if your password is compromised, access remains impossible without the second factor. Be aware that codes sent by SMS or e-mail are less secure, as they can be intercepted or diverted.

This reminder of the fundamentals will serve as a base for our SCU202 course, where we'll go much deeper into mastering cybersecurity techniques, to better protect your individual sovereignty, your privacy and your personal data overall.