Know and understand the differences between strong and weak passwords

4 Networks and the Effects of Using Them – Password Security

Objective

By the end of this unit students will be able to:

• Identify the main hardware components of a computer system and of a network (CPU, RAM, storage, NIC, router, switch, hub, bridge, Wi‑Fi, Bluetooth, cloud services).
• Explain the different types of networks (LAN, WLAN, WAN, MAN, Intranet, Extranet, Internet) and how they affect performance, congestion and privacy.
• Discuss the advantages, disadvantages and health impacts of using ICT.
• Distinguish between strong and weak passwords and explain why password strength matters.
• Apply basic security measures – strong passwords, 2‑FA, encryption, firewalls, anti‑malware and safe e‑behaviour – to protect personal and school data.

Recall: Core Computer Components (AO1)

• CPU (Central Processing Unit) – executes instructions; network devices run firmware on a CPU.
• RAM (Random‑Access Memory) – temporary storage for active processes; needed for routing tables and firewall rules.
• ROM/Flash memory – stores permanent firmware (e.g., router OS).
• Storage – HDD/SSD or cloud storage where data is saved and shared.
• Operating System (OS) – provides a GUI or CLI for configuring network settings (e.g., Windows, macOS, Linux, router firmware).

1 What Is a Network?

1.1 Core Network Hardware (AO1)

• Router – connects different networks (LAN ↔ Internet), maintains routing tables, performs NAT and often provides DHCP.
• Network Interface Card (NIC) – hardware inside a device that sends/receives data on wired or wireless links.
• Hub – repeats incoming signals to every port; no intelligence, so all traffic is broadcast.
• Switch – learns MAC addresses and forwards frames only to the intended destination, reducing collisions.
• Bridge – links two LAN segments and forwards traffic based on MAC addresses, useful for extending a network.
• Wireless Access Point (Wi‑Fi) – provides radio‑frequency connectivity for laptops, tablets and smartphones.
• Bluetooth – short‑range wireless technology for peripherals and ad‑hoc file sharing.
• Cloud Computing – delivery of storage, applications and processing over the Internet; accessed through a network connection.

1.2 Common Network Environments (AO1)

1.3 Network Performance – Congestion & Bandwidth (AO2)

When many users or large files use the same link, the network can become congested, causing:

• Latency – delay before data starts to transfer.
• Reduced throughput – lower effective bandwidth (e.g., a 100 Mbps link may feel like 20 Mbps under heavy load).
• Packet loss – data that never reaches its destination, leading to errors or retransmissions.

Good practice: limit simultaneous high‑bandwidth activities, use QoS (Quality of Service) settings on routers, and ensure the link’s capacity matches user demand.

1.4 Basic IP‑Address Concepts (AO1)

• IP addresses identify devices on a network (e.g., 192.168.1.15 for a home PC).
• A subnet mask (e.g., 255.255.255.0) defines the range of addresses that belong to the same LAN.
• Public IPs are routable on the Internet; private IPs are used only inside a LAN and are translated by NAT.

1.5 Simple Text‑Based Network Diagram

[Internet] ──► [Router] ──► [Switch] ──► [PC] (NIC)
│
└──► [Wireless Access Point] ──► [Laptop/Tablet]

2 Effects of Using Networks

2.1 Advantages (AO2)

• Resource sharing – printers, storage, internet connections.
• Collaboration – email, instant messaging, video‑conferencing, shared documents.
• Centralised data management – easier backup, version control and security policies.
• Cost efficiency – reduces duplicate hardware and software licences.
• Access to cloud services – scalable storage and applications without local installation.

2.2 Disadvantages / Risks (AO2)

• Security threats – unauthorised access, hacking, phishing, malware, ransomware.
• Network congestion – too many users or large transfers can slow performance (see 1.3).
• Single points of failure – a broken router or switch can affect many users.
• Privacy concerns – data may be intercepted if not encrypted.
• Health & lifestyle impacts (Section 5) – eye strain, musculoskeletal problems, sedentary behaviour.

2.3 Typical Security Threats (AO2 – 8.3)

• Hacking – gaining unauthorised access by exploiting software or configuration weaknesses.
• Phishing – deceptive messages that trick users into revealing credentials.
• Malware – viruses, worms, trojans and ransomware that damage or encrypt data.
• Identity theft / Card fraud – stealing personal or payment details.
• Man‑in‑the‑middle (MITM) – intercepting communication between two parties.

2.4 ICT Applications and Communication (AO1)

• Email – asynchronous communication; can be secured with TLS.
• Instant messaging & chat apps – e.g., Teams, Slack; often use end‑to‑end encryption.
• Video‑conferencing – Zoom, Google Meet; bandwidth‑intensive, requires good network performance.
• Cloud collaboration – Google Docs, OneDrive; files are stored on remote servers and accessed via the network.
• Social media – platforms for sharing content; present privacy and reputation risks.

2.5 Health & Lifestyle (AO1)

• Eye strain from prolonged screen use – take regular 20‑20‑20 breaks.
• Repetitive‑strain injuries (RSI) – maintain ergonomic posture, use supportive keyboards/mice.
• Reduced physical activity – incorporate movement breaks during long study sessions.
• Potential mental‑health impacts – manage online stress and maintain a healthy digital balance.

3 Password Security – Why It Matters (AO1 & AO2)

Passwords are the first line of defence for network resources. A weak password can give an attacker easy entry to a single account, and because many services reuse credentials, the whole network can be compromised.

3.1 Characteristics of Strong Passwords (AO1)

• Length – at least 12 characters; longer passwords increase entropy.
• Complexity – mix of uppercase, lowercase, digits and symbols.
• Unpredictability – no dictionary words, personal data or simple patterns.
• Uniqueness – a different password for every account or service.
• Entropy – aim for ≥ 60 bits (e.g., four random words + two symbols ≈ 64 bits).

3.2 Characteristics of Weak Passwords (AO1)

• Fewer than 8 characters.
• Only letters or only numbers.
• Common words, names, birthdays, “123456”, “password”.
• Reused across multiple accounts.
• Predictable patterns such as “qwerty”, “abcd1234”.

3.3 Comparison Table (AO1 – Knowledge)

3.4 Tips for Creating and Managing Strong Passwords (AO2)

1. Use a pass‑phrase – combine unrelated words and add numbers/symbols, e.g. Blue!River$28 or Solar*Maple%91.
2. Employ a reputable password manager – stores unique, complex passwords securely and can generate random ones.
3. Enable two‑factor authentication (2‑FA) – something you know (password) + something you have (code, token, authenticator app).
4. Consider biometric factors – fingerprint or facial recognition as an additional layer where supported.
5. Change passwords after a breach and at least once a year for critical accounts.
6. Never write passwords in plain view; use encrypted digital notes or a manager.

4 Additional Security Measures (AO2 – 8.3)

• Encryption – transforms data into unreadable form; use full‑disk encryption (e.g., BitLocker, FileVault) and encrypted messaging (e.g., Signal).
• SSL / TLS – secure protocol for web traffic; look for “https://” and the padlock icon.
• Firewalls – hardware or software that filters incoming/outgoing traffic based on rules.
• Anti‑malware / Antivirus – scans for viruses, trojans, ransomware and blocks suspicious downloads.
• Regular updates & patches – keep operating systems, browsers and apps current to close security holes.

5 e‑Safety and Data Protection (AO2 – 8.2)

• Personal data – name, address, date of birth, school ID, photographs. Treat it as confidential.
• GDPR‑style principles – collect only what is needed, keep it safe, and delete it when no longer required.
• Safe internet use – use reputable sites, check URLs, avoid downloading unknown files, and be cautious with pop‑ups.
• Social‑media etiquette – do not share passwords, location details or school‑related confidential information.
• Reporting – tell a teacher or parent if you receive a suspicious email, see inappropriate content, or suspect a security breach.

6 Copyright and Legal Issues (AO2)

When sharing files or using online resources, always respect copyright:

• Use material that is your own, in the public domain, or covered by a licence (e.g., Creative Commons).
• Give proper attribution when required.
• Do not distribute copyrighted software, music or video without permission.

7 Practical Activity (AO2 – Sections 11‑16)

Task: Create a password‑protected document that contains a short report on network security.

1. Write a 150‑word paragraph on why strong passwords are essential.
2. Apply the school’s file‑naming convention, e.g. YearGroupSubjectTopic_Date.docx.
3. Set a password using the pass‑phrase guidelines (minimum 12 characters, mix of symbols).
4. Save the file in a folder that is encrypted (BitLocker, VeraCrypt, or a compressed archive with a password).
5. Share the file with a partner using a secure method (school‑approved cloud link with restricted access).

After completing the task, discuss how the password, encryption and sharing method protect the data, linking the activity back to the concepts covered in this note.

8 Summary (AO1 & AO2)

Networks enable powerful collaboration but also expose users to a range of security threats and health considerations. Understanding the hardware, the different network environments, and the specific risks (hacking, phishing, malware, congestion, privacy) is essential. Strong, unique passwords – supported by 2‑FA, encryption, firewalls and anti‑malware – form the backbone of good e‑safety. By applying these principles in everyday tasks, students help keep their personal information, school data and the wider network safe.