Cybersecurity

You’ll be able to

Identify common cyber threats such as phishing and malware
Explain how encryption and authentication protect data
Apply good security practices like strong, unique passwords and multifactor authentication

Threats to data and systems

Cybersecurity is the practice of protecting computing systems and data from unauthorized access and attack. Common threats include phishing — deceptive messages that trick a user into revealing passwords or clicking a malicious link — and malware, harmful software (viruses, ransomware, keyloggers) that infects a device to steal data or cause damage. Many attacks exploit people rather than code: social engineering manipulates users into giving up access. The weakest link is often a person who is fooled, not a flaw in the software.

Encryption keeps data secret

Encryption scrambles data using a key so that only someone with the correct key can read it; to everyone else it is meaningless. In symmetric encryption the same key encrypts and decrypts, so both parties must share it secretly. In public key (asymmetric) encryption, a widely shared public key encrypts a message and only the matching private key can decrypt it — enabling secure communication between strangers without ever sharing a secret key. Encryption is what makes online banking, shopping, and private messaging safe from eavesdroppers.

Proving who you are

Authentication confirms that a user is who they claim to be. Passwords are the basic method, but they are weak when short, common, or reused across sites — one breach then unlocks many accounts. Multifactor authentication (MFA) strengthens this by requiring two or more kinds of evidence: something you know (password), something you have (a phone or security key), or something you are (a fingerprint). Even if an attacker steals your password, they still lack the second factor. Strong, unique passwords plus MFA are the most effective everyday defenses.

Multifactor authentication

MFA = two or more of: something you know + something you have + something you are

Combining independent factors means a stolen password alone is not enough to break in.

Worked example

A user receives an email that looks like it is from their bank, warning of a locked account and linking to a page that asks for their password. What kind of attack is this, and how should the user respond?

1.Recognize the tactic: an urgent, official-looking message designed to trick the user into entering credentials on a fake page — this is phishing (a form of social engineering).
2.Note the red flags: unexpected urgency, a link to a login page, and a request for the password.
3.The user should not click the link or enter any password; instead, visit the bank directly by typing its known address or calling it.
4.Having MFA enabled adds protection: even if a password were phished, the attacker would still lack the second factor.

Answer: This is a phishing attack that uses social engineering to steal the password. The user should avoid the link, contact the bank through a trusted channel, and rely on defenses like unique passwords and multifactor authentication so a single stolen password is not enough.

Checkpoint

An attacker sends thousands of emails pretending to be a popular service, urging recipients to "verify" their password on a fake login page. This attack is best described as:

Tip

The most common attacks target people, not code. Be suspicious of any unexpected message creating urgency and asking for credentials — and never reuse the same password across important accounts.

Checkpoint

Why does enabling multifactor authentication (MFA) protect an account even if the user’s password is stolen?

On the exam

Match each defense to its job: encryption protects data confidentiality in transit and storage; authentication/MFA verifies identity. Phishing and malware are threats; strong unique passwords and MFA are the everyday defenses.

Answer the 2 checkpoints as you read.