Session 02.pdf

# E-commerce infrastructure and the internet This section details the foundational elements of e-commerce infrastructure, focusing on the Internet, its evolution, and key underlying technologies that enable its functionality. ### 1.1 The Internet The Internet is a vast, interconnected network comprising thousands of individual networks and millions of computers, linking businesses, educational institutions, government agencies, and individuals globally [3](#page=3). #### 1.1.1 Evolution of the Internet The Internet's development can be divided into three key phases: * **Innovation phase (1961–1974):** This period saw the creation of fundamental building blocks such as packet switching, the TCP/IP communications protocol, and client/server computing [4](#page=4). * **Institutionalization phase (1975–1995):** Large institutions provided crucial funding and legitimacy for the Internet's growth [4](#page=4). * **Commercialization phase (1995–present):** Private corporations assumed control, expanding the Internet's backbone and local service capabilities worldwide [4](#page=4). ### 1.2 Key Internet Technologies #### 1.2.1 Packet switching Packet switching is a fundamental technology for digital communication. It involves: * Slicing digital messages into small units called packets [5](#page=5). * Sending these packets along different communication paths as they become available [5](#page=5). * Reassembling the packets at their destination [5](#page=5). * Utilizing routers to interconnect various computer networks [5](#page=5). This method is generally less expensive and more efficient than traditional circuit switching. In circuit switching, dedicated connections are established for each communication, which limits the number of simultaneous exchanges possible within a network. Conversely, packet switching allows for fair access to shared network resources by breaking files into data packets for transfer, enabling multiple communications to share a transmission line [5](#page=5) [8](#page=8) [9](#page=9). #### 1.2.2 TCP/IP Transmission Control Protocol/Internet Protocol (TCP/IP) is the suite of communications protocols used to interconnect network devices on the Internet [4](#page=4). * **Transmission Control Protocol (TCP):** This protocol establishes connections between sending and receiving computers and manages the assembly of packets at the transmission point and their reassembly at the receiving end [10](#page=10). * **Internet Protocol (IP):** This protocol provides the addressing scheme for packets and is responsible for their delivery [10](#page=10). The TCP/IP protocol suite is structured into four layers: * **Network interface layer:** Manages the placement of packets onto and their reception from the network medium [11](#page=11). * **Internet layer:** Handles addressing, packaging, and routing of messages [11](#page=11). * **Transport layer:** Facilitates communication with other protocols within the TCP/IP suite [11](#page=11). * **Application layer:** Includes protocols used to provide user services or exchange data [11](#page=11). #### 1.2.3 IP addresses and Domain Names * **IP addresses:** These are numerical labels assigned to each device connected to a computer network that uses the Internet Protocol for communication [13](#page=13). * **IP v4:** A 32-bit number, typically represented as four sets of numbers separated by periods (e.g., 201.61.186.227). It can handle up to approximately 4 billion addresses [13](#page=13). * **IP v6:** A 128-bit address, capable of handling up to 1 quadrillion addresses [13](#page=13). * **Domain names:** These are human-readable text versions of IP addresses [14](#page=14). * **Domain Name System (DNS):** This system allows for the translation of numeric IP addresses into natural language domain names, making it easier for users to access websites [14](#page=14). * **Uniform Resource Locator (URL):** This is the address used by a web browser to locate specific content on the Web. A URL typically includes the protocol (e.g., `http://`), the domain name (e.g., `www.google.com`), and potentially the path to a specific file or page [14](#page=14) [15](#page=15). #### 1.2.4 Client/Server Computing This model describes how resources and services are shared across a network: * **Clients:** Devices that can request access to services or resources from other computers [17](#page=17). * **Servers:** Computers dedicated to performing common functions for clients, such as file storage, software applications, Internet access, or printer access [17](#page=17). ### 1.3 Emerging E-commerce Infrastructure Components #### 1.3.1 The Mobile Platform The increasing prevalence of mobile devices has become a significant aspect of e-commerce infrastructure: * **Smartphones:** A large number of users access the Internet via smartphones like the Apple iPhone and Samsung Galaxy [18](#page=18). * **Tablets:** Tablets, such as the Apple iPad and Microsoft Surface, also provide Internet access for a substantial user base [18](#page=18). #### 1.3.2 The Cloud Computing Model Cloud computing provides computing processing, storage, software, and other services as a shared pool of virtualized resources delivered over the Internet [19](#page=19). * **Primary Service Types:** * Infrastructure as a Service (IaaS) * Software as a Service (SaaS) * Platform as a Service (PaaS) * **Cloud Deployment Models:** Public, private, and hybrid clouds [19](#page=19). **Benefits of Cloud Computing:** * Cost reductions in building and operating websites, including infrastructure and IT support [20](#page=20). * Reduced costs for hardware and software [20](#page=20). **Drawbacks of Cloud Computing:** * Shifts responsibility for data storage and control to providers [20](#page=20). * Can introduce delays in data processing and transmission [20](#page=20). * Introduces potential security risks [20](#page=20). #### 1.3.3 The Internet of Things (IoT) The Internet of Things (IoT) enables objects to connect to the Internet through sensors or RFID technology [21](#page=21). * **Enablers:** The growth of IoT is driven by the availability of low-cost sensors, decreasing data storage prices, the development of big data analytics software, the implementation of IPv6, and the creation of "smart" connected devices [21](#page=21). * **Concerns:** Challenges related to IoT include interoperability, privacy, and security [21](#page=21). ### 1.4 The World Wide Web (Web) The World Wide Web is one of the most popular services offered by the Internet, providing access to an estimated trillions of web pages. It is built upon the Internet's infrastructure and enables the retrieval and display of information through web browsers [3](#page=3). --- # The World Wide Web and its features The World Wide Web is a vast information space where documents and other web resources are identified by Uniform Resource Locators (URLs), interlinked by hypertext links, and can be accessed via the Internet. This section details its invention, the evolution of web browsers, the foundational technologies like HTML and XML, and the diverse features and services it offers [23](#page=23). ### 2.1 Invention and early development The World Wide Web was invented by Tim Berners-Lee between 1989 and 1991. A key component of the web is hypertext, which is text formatted with embedded links that connect documents to each other and to other media types like sound, video, or animation files [23](#page=23) [24](#page=24). The development of web browsers was crucial for making the web accessible. Mosaic, released in 1993, was the first web browser to feature a graphical user interface. This was followed by Netscape Navigator in 1994, which was the first commercial web browser. Microsoft entered the market in 1995 with Internet Explorer [23](#page=23). ### 2.2 Underlying technologies Two fundamental markup languages underpin the World Wide Web: * **Hypertext Markup Language (HTML)**: This language uses a fixed set of pre-defined markup "tags" to format text and control the look and feel of web pages [24](#page=24). * **eXtensible Markup Language (XML)**: In contrast to HTML, XML is designed to describe data and information, and the tags used are defined by the user, offering greater flexibility in data representation [24](#page=24). > **Tip:** Understanding the difference between HTML (for presentation) and XML (for data description) is key to grasping how web content is structured and interpreted. ### 2.3 Web servers and clients The web operates on a client-server model: * **Web server software**: This software enables a computer to deliver HTML web pages to clients upon receiving an HTTP request [26](#page=26). * **Web server**: This refers to the physical computer that runs the web server software. Specialized server software also exists, such as database servers, ad servers, mail servers, and media servers [26](#page=26). * **Web client**: This is any computing device connected to the Internet capable of making HTTP requests and displaying HTML pages [26](#page=26). ### 2.4 Web browsers The primary function of web browsers is to display web pages to users. Major web browsers and their approximate market shares (as of the document's content) include [27](#page=27): * **Google Chrome**: Dominant on desktop (about 60% share) and significant on mobile (about 40% share) [27](#page=27). * **Apple Safari**: Strong on mobile (about 55% share) and notable on desktop (about 18% share) [27](#page=27). * **Microsoft Edge**: Has replaced Internet Explorer and holds about 12% of the desktop market share [27](#page=27). * **Mozilla Firefox**: Holds about 7% of the desktop market share [27](#page=27). > **Example:** When you type a web address into your browser and press Enter, your browser (the client) sends an HTTP request to the web server hosting that site. The server then sends the requested HTML page back to your browser for display. ### 2.5 Features and services of the World Wide Web The World Wide Web offers a wide array of features and services, evolving significantly over time: #### 2.5.1 Communication tools These tools facilitate interaction and connection among users: * **E-mail**: The most widely used application on the Internet [29](#page=29). * **Messaging applications**: Enable real-time message exchange, often referred to as instant messaging [29](#page=29). * **Online message boards and forums**: Platforms for asynchronous discussions on various topics [29](#page=29). * **Internet telephony**: Utilizes Voice over Internet Protocol (VOIP) for voice communication over the internet [29](#page=29). * **Videoconferencing, video chatting, and telepresence**: Advanced forms of communication that can include immersive environments with surrounding cameras and screens [29](#page=29). #### 2.5.2 Search engines Search engines are vital tools for navigating the vastness of the web. They: * Identify web pages that match user queries and present a list of the most relevant results [30](#page=30). * Serve as advertising vehicles, a practice known as search engine marketing [30](#page=30). * Function as shopping tools [30](#page=30). * Major providers include Google and Bing [30](#page=30). #### 2.5.3 Downloadable and streaming media The web provides access to various forms of media: * **Downloads**: Files are transferred from a web server and stored locally on the user's computer [32](#page=32). * **Streaming**: Media is played as it is being delivered, without requiring the entire file to be downloaded first [32](#page=32). * **Podcasts**: Digital audio presentations, often delivered via streaming or download [32](#page=32). #### 2.5.4 Web 2.0 applications and services Web 2.0 represents a shift towards user-generated content and interactivity: * **Online social networks**: Support communication and connection among networks of friends, colleagues, and individuals with shared interests [33](#page=33). * **Blogs**: Personal web pages featuring chronological entries of thoughts, opinions, or information [33](#page=33). * **Wikis**: Web applications that empower users to easily add and edit content on web pages, facilitating collaborative knowledge creation [33](#page=33). #### 2.5.5 Virtual reality, augmented reality, and the metaverse These technologies are creating new immersive digital experiences: * **Virtual reality (VR)**: Aims to immerse users within a completely virtual world, typically using head-mounted displays (HMDs) like Gear VR or PlayStation VR [34](#page=34). * **Augmented reality (AR)**: Overlays virtual objects onto the real-world environment, as seen in applications like Pokémon GO or Spark AR Studio [34](#page=34). * **Metaverse**: Envisions an immersive, visual 3-D virtual reality space where users can connect, socialize, collaborate, and conduct transactions [34](#page=34). #### 2.5.6 Intelligent digital assistants These are advanced computer search engines that use: * **Natural language processing**: Allowing users to interact through conversational interfaces and verbal commands [35](#page=35). * **Situational awareness**: The ability to understand context and user needs [35](#page=35). * Examples include Amazon Echo and Apple HomePod [35](#page=35). #### 2.5.7 Mobile apps The widespread adoption of smartphones has led to the proliferation of mobile applications: * These apps run on various **platforms** such as Android and iOS [36](#page=36). * **App marketplaces**, like Google Play and Apple's App Store, serve as central hubs for downloading and managing these applications [36](#page=36). --- # E-commerce security environment and threats The e-commerce security environment is complex, facing numerous threats across clients, servers, and communication channels, necessitating a multi-faceted approach involving new technologies, organizational policies, industry standards, and government laws to mitigate risks [38](#page=38). ### 3.1 Scope of the e-commerce security problem The true scope of e-commerce security issues is difficult to ascertain as many companies are hesitant to report cybercrime. The estimated global economic impact of cybercrime and cyberespionage exceeds one trillion dollars. A significant portion of these activities occurs within the shadow or underground economy, often facilitated by the Dark Web or Darknet, where stolen information and malware are traded, frequently in exchange for cryptocurrency. Achieving the highest degree of security requires a combination of new technologies, organizational policies and procedures, industry standards, and government laws. Security is often compromised at its weakest link, and there is a constant tension between the cost of security measures and the potential financial losses, as well as between security and ease of use [37](#page=37) [38](#page=38). ### 3.2 Key points of vulnerability The e-commerce environment has three primary points of vulnerability [41](#page=41): * **Client:** This refers to the user's device and software. * **Server:** This encompasses the e-commerce website's infrastructure and databases. * **Communications pipeline:** This is the network through which data travels between the client and the server. ### 3.3 Common e-commerce security threats A wide array of security threats targets the e-commerce ecosystem. These include [43](#page=43) [44](#page=44): #### 3.3.1 Malicious code (malware) Malware encompasses a range of harmful software designed to infiltrate and damage computer systems. Common types include [45](#page=45): * **Exploits and exploit kits:** Software designed to take advantage of vulnerabilities in systems [45](#page=45). * **Drive-by downloads:** Malware downloaded onto a user's device without their knowledge or consent, often by simply visiting a compromised website [45](#page=45). * **Malvertising:** Malicious code hidden within online advertisements [45](#page=45). * **Viruses:** Malware that attaches itself to other programs and replicates [45](#page=45). * **Worms:** Self-replicating malware that spreads across networks [45](#page=45). * **Ransomware:** Malware that encrypts a victim's data and demands a ransom for its decryption [45](#page=45). * **Trojan horses:** Malware disguised as legitimate software [45](#page=45). * **Backdoors:** A hidden method of bypassing normal authentication or encryption to gain unauthorized access to a computer system [45](#page=45). * **Bots and botnets:** Automated programs (bots) that can be controlled remotely, often in large networks (botnets) used for malicious activities [45](#page=45). #### 3.3.2 Potentially unwanted programs (PUPs) PUPs are software that users may find annoying or intrusive, though not always overtly malicious. These include [47](#page=47): * **Adware:** Software that displays unwanted advertisements, often in the form of pop-ups [47](#page=47). * **Browser parasites:** Programs that monitor and alter a user's browser settings or behavior [47](#page=47). * **Cryptojacking:** The unauthorized use of a user's computing resources to mine cryptocurrency [47](#page=47). * **Spyware:** Malware that tracks a user's activities, including keystrokes, emails, and instant messages [47](#page=47). #### 3.3.3 Phishing Phishing involves deceptive online attempts by third parties to obtain confidential information for financial gain. Key tactics include [49](#page=49): * **Social engineering:** Manipulating individuals into divulging confidential information [49](#page=49). * **BEC (Business Email Compromise) phishing:** Targeted phishing attacks aimed at businesses, often impersonating executives to trick employees into making wire transfers or revealing sensitive data [49](#page=49). * **Spear phishing:** Highly targeted phishing attacks that are customized for specific individuals or organizations [49](#page=49). #### 3.3.4 Hacking, cybervandalism, and hacktivism * **Hacking:** The unauthorized access to computer systems. Hackers are categorized as white hats (ethical hackers), black hats (malicious hackers), and grey hats (operating in a moral ambiguity). Ethical hackers, tiger teams, and bug bounty hunters are employed to find vulnerabilities [52](#page=52). * **Cybervandalism:** The electronic counterpart of vandalism, typically involving the disruption or defacement of websites [52](#page=52). * **Hacktivism:** The use of hacking to achieve political or social goals [52](#page=52). * **Doxing:** The act of publicly revealing private or identifying information about an individual or organization, usually with malicious intent [52](#page=52). #### 3.3.5 Data breaches A data breach occurs when an organization loses control of its corporate information to unauthorized outsiders. Common causes include human and system errors, as well as malicious code. **Credential stuffing**, where stolen login credentials from one breach are used to attempt unauthorized access to other services, is a significant factor [54](#page=54). #### 3.3.6 Credit card fraud/theft This is a highly feared occurrence, primarily resulting from system hacking and the theft of data from corporate servers. A central security challenge is establishing a customer's true identity online. Solutions include e-signatures, fingerprint identification, and multi-factor authentication [56](#page=56). #### 3.3.7 Identity fraud/theft This involves the unauthorized use of another person's personal data for illegal financial gain. The personal data targeted can include credit card numbers, driver's license information, social security numbers, usernames, and passwords [57](#page=57). #### 3.3.8 Spoofing, pharming, and spam (junk) websites * **Spoofing:** An attempt to disguise one's true identity by using another person's email address or IP address [58](#page=58). * **Pharming:** Automatically redirecting a user's requested URL to a different, malicious address to benefit the hacker [58](#page=58). * **Spam (junk) websites:** Websites that offer collections of advertisements, which may contain malicious code [58](#page=58). #### 3.3.9 Sniffing, wiretaps, and man-in-the-middle attacks * **Sniffer:** A program that eavesdrops on network traffic, which can be used by criminals to steal proprietary information. While also useful for identifying network trouble spots, its malicious use is a significant threat [59](#page=59). * **E-mail wiretaps:** Recording emails at the mail server level [59](#page=59). * **Man-in-the-middle (MitM) attacks:** An attacker intercepts and potentially alters communications between two parties who believe they are communicating directly [59](#page=59). #### 3.3.10 (Distributed) denial of service attacks * **Denial of Service (DoS) attack:** Floods a website with excessive pings and page requests, overwhelming and potentially shutting down its web servers [60](#page=60). * **Distributed Denial of Service (DDoS) attack:** Utilizes hundreds or thousands of compromised computers (often including devices from the Internet of Things and mobile devices) to attack a target network. **DDoS smokescreening** is a tactic used to mask other malicious activities during a DDoS attack [60](#page=60). #### 3.3.11 Insider attacks Insider threats are often more dangerous than external ones, as employees typically have privileged access to sensitive information. Poor security procedures can exacerbate this risk, and insider attacks can be accidental or intentional [61](#page=61). #### 3.3.12 Poorly designed software The complexity and demand for software have led to an increase in flaws and vulnerabilities. **SQL injection attacks**, where users can input data that manipulates database queries, are a significant risk, with many web applications believed to be vulnerable. A **zero-day vulnerability** refers to a flaw that is unknown to the software vendor and for which no patch exists [62](#page=62). #### 3.3.13 Social network security issues Social networks are fertile ground for malware-loaded apps, viruses, phishing, spam, and identity fraud. Threats include manual sharing scams, sharing files that link to malicious sites, and fake offerings, like buttons or apps designed to trick users [63](#page=63). #### 3.3.14 Mobile platform security issues There is often a low public awareness of mobile device vulnerabilities. Specific threats include [64](#page=64): * **Madware:** Malware that originates from mobile advertising [64](#page=64). * **Vishing:** Voice phishing, using phone calls to deceive individuals into revealing information [64](#page=64). * **Smishing:** SMS phishing, using text messages to trick users [64](#page=64). * **SMS spoofing:** Falsifying the sender ID of an SMS message [64](#page=64). #### 3.3.15 Cloud security issues Concerns exist regarding the safeguarding of data stored in public clouds. While cloud providers offer security measures, most organizations do not take full responsibility for the security of their data within these environments, leaving them vulnerable to threats like DDoS attacks [66](#page=66). #### 3.3.16 Internet of Things (IoT) security issues The vast array of interconnected IoT devices presents a broad attack surface. Many IoT devices share similar characteristics and have long service lives, often lacking essential security upgrades or alerts for known problems, making them susceptible to exploitation [67](#page=67). #### 3.3.17 Metaverse security issues The metaverse, utilizing Virtual Reality (VR) and Augmented Reality (AR) hardware, introduces new attack endpoints. Attackers could potentially create physical dangers for users, participants may face harassment, and risks include identity theft, theft of digital currencies, and privacy violations related to personal information collected within these virtual environments [68](#page=68). --- # Technology solutions for e-commerce security This topic outlines the technological solutions employed to protect internet communications, networks, servers, and clients against various security threats [70](#page=70). ### 4.1 Protecting internet communications Protecting internet communications involves ensuring that data transmitted over the internet remains confidential and unaltered. Key technologies and methods include [70](#page=70): #### 4.1.1 Encryption Encryption is a fundamental process that transforms readable data (plaintext) into an unreadable format (ciphertext) using algorithms and keys. This ensures that even if data is intercepted, it cannot be understood without the correct decryption key [70](#page=70). #### 4.1.2 Securing channels of communication Securing channels of communication refers to the implementation of protocols and technologies that create protected pathways for data transmission. * **Transport Layer Security (TLS)**: TLS is a cryptographic protocol designed to provide communications security over a computer network. It is widely used for securing internet communications, particularly for web browsing (HTTPS). TLS encrypts the data exchanged between a client (e.g., a web browser) and a server, preventing eavesdropping and tampering [70](#page=70). * **Virtual Private Networks (VPNs)**: VPNs create an encrypted tunnel over a public network, such as the internet, allowing users to send and receive data as if their devices were directly connected to a private network. This is particularly useful for remote workers or users accessing sensitive information [70](#page=70). * **Wi-Fi Security Protocols**: Secure Wi-Fi connections are crucial, especially in public spaces. Protocols like WPA2 and WPA3 use encryption to protect wireless network traffic from unauthorized access [70](#page=70). ### 4.2 Protecting networks Network security focuses on safeguarding the integrity, confidentiality, and accessibility of computer networks. #### 4.2.1 Firewalls Firewalls act as a barrier between a trusted internal network and untrusted external networks (like the internet). They monitor incoming and outgoing network traffic and decide whether to allow or block specific traffic based on a defined set of security rules [70](#page=70). #### 4.2.2 Proxy servers Proxy servers act as intermediaries between users and the internet. They can provide various security functions, including filtering requests, caching data to improve performance, and masking the IP addresses of client devices, thereby enhancing anonymity and security [70](#page=70). #### 4.2.3 Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) * **Intrusion Detection Systems (IDS)**: An IDS monitors network traffic for suspicious activity or policy violations and alerts administrators when such activity is detected. It is primarily a monitoring and alerting tool [70](#page=70). * **Intrusion Prevention Systems (IPS)**: An IPS goes a step further than an IDS by not only detecting malicious activity but also attempting to actively prevent it. This can involve blocking traffic, resetting connections, or taking other preventive measures [70](#page=70). ### 4.3 Protecting servers and clients Securing individual devices and the servers they connect to is vital for overall e-commerce security. #### 4.3.1 Operating system security Maintaining secure operating systems involves regular patching, configuration hardening, and disabling unnecessary services to reduce the attack surface. This prevents vulnerabilities from being exploited by attackers [70](#page=70). #### 4.3.2 Anti-virus software Anti-virus software is designed to detect, prevent, and remove malicious software (malware), such as viruses, worms, and trojans, from computers and servers. Regular updates to anti-virus definitions are crucial for effective protection against emerging threats [70](#page=70). --- ## Common mistakes to avoid - Review all topics thoroughly before exams - Pay attention to formulas and key definitions - Practice with examples provided in each section - Don't memorize without understanding the underlying concepts

| Term | Definition | |------|------------| | Packet switching | A method of transmitting data that breaks digital messages into packets, sends them along different paths, and reassembles them at the destination. It uses routers to interconnect networks and is generally more efficient than circuit switching. | | TCP/IP | A suite of communication protocols used for the Internet. TCP (Transmission Control Protocol) handles packet assembly and reassembly, while IP (Internet Protocol) manages addressing and packet delivery. It is structured into four layers: network interface, internet, transport, and application. | | IP address | A numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. IPv4 uses 32-bit addresses, while IPv6 uses 128-bit addresses, supporting a vastly larger number of devices. | | Domain name system (DNS) | A hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network. It translates human-readable domain names into machine-readable IP addresses. | | Uniform Resource Locator (URL) | An address used by web browsers to identify the location of content on the World Wide Web. It specifies the protocol, domain name, and the specific path to a resource. | | Client/server computing | A distributed application structure that partitions tasks or workloads between providers of a resource or service, called servers, and service requesters, called clients. Clients request services, and servers provide them. | | Cloud computing | The delivery of computing services—including servers, storage, databases, networking, software, analytics, and intelligence—over the Internet (“the cloud”) to offer faster innovation, flexible resources, and economies of scale. | | Hypertext Markup Language (HTML) | The standard markup language for documents designed to be displayed in a web browser. It uses predefined tags to structure content and control the appearance of web pages. | | Web server | Software and hardware that deliver web pages to users. The web server software listens for HTTP requests from clients, processes them, and sends back the requested HTML pages or other content. | | Phishing | A type of social engineering attack used to steal user data, including login credentials and credit card numbers. It occurs when an attacker, masquerading as a trusted entity, dupes a victim into opening an email, instant message, or text message. | | Malware | Short for malicious software, it is any software intentionally designed to cause damage to a computer, server, client, or computer network. Examples include viruses, worms, ransomware, and spyware. | | Denial of Service (DoS) attack | An attack where the attacker makes a machine or network resource unavailable to its intended users, typically by overwhelming the target with traffic from multiple sources. A Distributed Denial of Service (DDoS) attack uses a large number of compromised computers to launch the attack. | | Encryption | The process of converting information or data into a code, especially to prevent unauthorized access. It is a critical technology for protecting the confidentiality and integrity of data during transmission and storage. | | Firewall | A network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It establishes a barrier between a trusted internal network and untrusted external network, such as the Internet. | | Man-in-the-middle attack | A type of cyberattack where an attacker secretly relays and possibly alters the communication between two parties who believe they are directly communicating with each other. |