Cyber Technology

Basics of Wi-Fi

Wired networks transmit data through cables, while wireless networks use radio waves for communication. Ethernet is the most common example of a wired network, whereas Wi-Fi (Wireless Fidelity) represents wireless networking technology based on IEEE 802.11 standards.

Wi-Fi-enabled devices connect to the internet using a WLAN network through a Wireless Access Point (AP). Each WLAN has an AP, responsible for receiving and transmitting data between connected devices. The IEEE 802.11 specifications govern the physical and data link layers of wireless LANs.

Access Point (AP) and WLAN Architecture

An Access Point (AP) acts as a wireless LAN base station, connecting multiple wireless devices to the internet. The IEEE 802.11 architecture consists of two main components:

1. BSS (Basic Service Set)

• The Basic Service Set (BSS) is the fundamental component of a WLAN, composed of wireless devices (stations) and an optional AP.
• Ad-hoc Network (Independent BSS or IBSS): A BSS without an AP functions as a standalone network where devices communicate directly.
• Infrastructure Network: A BSS with an AP connects devices through the AP, enabling data exchange and internet access.

2. ESS (Extended Service Set)

• The Extended Service Set (ESS) comprises multiple BSSs, each with an AP, interconnected through a distribution system (e.g., Ethernet).
• Stations in an ESS are categorized as:
  • Mobile Stations: Devices within a BSS.
  • Stationary Stations: APs connected to a wired LAN.

Features of Wi-Fi

• Wireless Connectivity
  Wi-Fi eliminates the need for physical cables, offering flexibility and mobility.
• High Speed
  Provides fast internet access for seamless downloads and uploads.
• Easy Setup
  Wi-Fi networks are simple to configure, with most modern devices supporting built-in Wi-Fi.
• Multiple Device Connectivity
  Allows several devices to connect simultaneously to the same network.
• Security
  Wi-Fi can be secured using encryption methods to prevent unauthorized access.
• Range
  Covers a wide area depending on the router and environmental factors.
• Compatibility
  Works seamlessly with various devices like smartphones, laptops, and smart home gadgets.
• Interference
  Wi-Fi signals may experience interference from other wireless devices or physical obstacles.

The Internet and the Web

The internet is a worldwide network of interconnected servers and computers, enabling people to communicate, share resources, and access information globally. Developed in the 1960s by the U.S. Department of Defense, it was initially created to connect researchers and scientists for data sharing.

The World Wide Web (web) is a system of linked documents and resources accessed via hyperlinks and URLs. Tim Berners-Lee introduced it in 1989 to help scientists share information efficiently. Over time, it evolved into the primary method for accessing data on the internet.

Together, the internet and the web have transformed industries, communication, business operations, and the dissemination of information, allowing people to connect instantly across the globe.

Key Concepts

1. The Internet

The internet is a global system of smaller interconnected networks, unified by standard communication protocols. It operates using the Internet Protocol Suite, which organizes its processes into layers:

• Application Layer: Manages data handling, including URLs, HTTP, HTTPS, etc.
• Transport Layer: Ensures end-to-end communication between devices.
• Network Layer: Provides routes for transmitting data.

2. The World Wide Web

The web is a system enabling access to internet resources through specially formatted documents written in HTML (HyperText Markup Language). These documents are connected through hyperlinks and accessible via web browsers using protocols like HTTP.

To link hypertext to the internet, the following are required:

• HTML: For formatting documents.
• HTTP/HTTPS: For transferring data.
• URL: For locating resources.

Differences Between the Internet and the Web

Internet	Web
A global network of networks allowing data exchange.	A platform for accessing and sharing information over the internet.
Known as the “Network of Networks.”	A system of interconnected websites.
Transports data using network protocols like TCP/IP, SMTP, etc.	Uses HTTP and HTTPS for web page access.
Accessible through various devices.	Accessed through web browsers.
Provides the infrastructure for online services like email and cloud storage.	Facilitates access to multimedia and resources on the internet.
No single creator.	Created by Tim Berners-Lee in 1989.

Uniform Resource Identifier (URI)

A URI is a name, locator, or identifier for an online resource, whereas a URL is specifically a locator. URLs are a subset of URIs and consist of:

• Protocol: HTTP/HTTPS.
• Website Name: (e.g., google, wikipedia).
• Top-Level Domain: .com, .org, .edu, etc.
• Path: Specific folders or subfolders within a site.

Governance of the Internet

The internet operates without centralized authority but is overseen by organizations like:

• ISOC (Internet Society): Promotes global information exchange using internet technology.
• IAB (Internet Architecture Board): Reviews standards and allocates resources.
• IETF (Internet Engineering Task Force): Discusses operational and technical issues.

Uses of the Internet and the Web

• Communication: Enables faster and easier communication, such as emails and video calls.
• Information Sharing: Provides access to vast knowledge resources.
• Online Shopping: Revolutionizes purchasing methods by providing e-commerce platforms.
• Entertainment: Offers movies, games, and music through online platforms.
• Education: Facilitates online learning and access to digital resources.
• Business: Enhances operations, allowing global market access.
• Research: Simplifies data collection and collaboration.

Passive Attacks

Passive attacks focus on observing or monitoring data transmission without altering or destroying the data. These attacks aim to collect sensitive information covertly.

Types of Passive Attacks:

1. Release of Message Content
Attackers monitor communication, such as emails or file transfers, to access sensitive information. For example, they might intercept encrypted messages during transmission.

2. Traffic Analysis
Even if data is encrypted, attackers analyze the metadata, such as frequency, size, or source/destination of messages, to infer patterns or relationships. Encrypting both the data and metadata can mitigate these attacks.

Types of Security Mechanism

A security mechanism refers to a method or technology designed to safeguard data and systems against unauthorized access, cyber-attacks, and other potential threats. By implementing security mechanisms, organizations ensure data integrity, confidentiality, and availability, thereby securing sensitive information and fostering trust in digital operations.

What is Network Security?

Network Security focuses on protecting computer networks and their infrastructure from threats. Networks are essential for sharing resources, such as printers and scanners, or exchanging data. Security mechanisms are processes designed to recover from specific threats across different protocol layers, ensuring the network remains secure.

Types of Security Mechanisms

1. Encipherment: Encipherment involves transforming data into an unreadable format to maintain confidentiality. This is achieved through mathematical algorithms or calculations that obscure the original data. Popular techniques include Cryptography and Encipherment itself. The strength of encryption depends on the algorithm used.

Example:

• Before encryption: “UserPassword123”
• After encryption: “W2@45**6$%Hj1z

2. Access Control: Access Control restricts unauthorized access to data during transmission. Techniques include setting up passwords, implementing firewalls, or applying PIN codes to protect the data.

Example: A secure login page that requires a username and password to access sensitive information.

3. Notarization: Notarization involves using a trusted third party during communication. The third party acts as a mediator between the sender and receiver, reducing potential disputes and maintaining a log of requests for future reference.

Example: A financial transaction where a trusted payment gateway logs transaction details for both parties.

5. Authentication Exchange: Authentication Exchange ensures the identity of the communicating parties. This is commonly achieved through a two-way handshake at the TCP/IP layer to verify the authenticity of the sender and receiver.

Example: A system where both parties share a unique session key during initial connection to confirm identity.

5. Authentication Exchange: Authentication Exchange ensures the identity of the communicating parties. This is commonly achieved through a two-way handshake at the TCP/IP layer to verify the authenticity of the sender and receiver.

Example: A system where both parties share a unique session key during initial connection to confirm identity.

6. Digital Signature: A Digital Signature is an electronic signature attached to data by the sender. It verifies the sender’s identity without compromising confidentiality. The receiver uses electronic verification to ensure authenticity.

Example: A digitally signed email where the recipient can validate the sender’s identity through a unique digital certificate.

Cryptography and Network Security Principles

Protecting data from attackers is the primary focus. In cryptography, there are two categories of attacks: Passive attacks and Active attacks.

• Passive attacks involve gathering information from the system without altering its resources.
• Active attacks not only retrieve system data but also modify system resources and operations.

Security Principles

The foundational principles of security are outlined below:

1. Confidentiality: Confidentiality determines how secret the information remains. This principle ensures that only the sender and the intended receiver can access the shared data. Confidentiality is compromised if an unauthorized person gains access to the information.
Example: If sender A sends confidential information to receiver B, and attacker C intercepts it, the information is no longer confidential, as it is now in C’s possession.

2. Authentication: Authentication is the process of verifying the identity of a user, system, or entity. It ensures that only authorized individuals can access sensitive data. Commonly, authentication involves a username and password.

3. Integrity: Integrity guarantees that the received information is accurate and unchanged. If a message is altered after being sent but before being received, its integrity is compromised.

• System Integrity: Ensures a system performs its functions correctly, free from unauthorized changes.
• Data Integrity: Ensures that stored or transmitted information and programs are altered only in approved ways.

4. Non-Repudiation: This principle prevents the denial of message content sent through a network. If a sender sends a message and later denies doing so, non-repudiation ensures accountability, preventing such denials.

5. Access Control: Access control involves managing roles and rules to determine who can access data and to what extent. Role management defines who is authorized to access information, while rule management specifies the permissible level of access.

6. Availability: Availability ensures that authorized users have access to resources whenever needed. If information isn’t accessible, it loses its value. Systems must maintain sufficient availability to meet user demands.

7. Ethical and Legal Considerations
Ethical dilemmas in security systems fall under several categories:

• Privacy: Refers to individuals’ rights to access their personal information.
• Property: Concerns the ownership of information.
• Accessibility: Deals with an organization’s right to collect data.
• Accuracy: Involves the authenticity, fidelity, and accuracy of information.