Chapter 5: The Internet and Its Uses - PDF

Chapter 5 The internet and its uses  You shoulkd know : 1. Understand the difference between the internet and the world wide web 2. Understand what is meant by a uniform resource locator (URL) 3. Describe the purpose and operation of hypertext transfer protocol (HTTP) and hypertext transfer prot...

Chapter 5 The internet and its uses  You shoulkd know : 1. Understand the difference between the internet and the world wide web 2. Understand what is meant by a uniform resource locator (URL) 3. Describe the purpose and operation of hypertext transfer protocol (HTTP) and hypertext transfer protocol secure (HTTPS) 4. Explain the purpose and functions of a web browser 5. Describe how web pages are located, retrieved and displayed on a device when a user enters a URL 6. Explain what is meant by cookies and how they are used, including session cookies and persistent cookies 7. Digital currency :- Understand the concept of a digital currency and how digital currencies are used -Understand the process of blockchain and how it is used to track digital currency transactions 8. Cyber security :Describe the processes involved in, and the aim of carrying out, a range of cyber security threats  5.1 The internet and the world wide web A network : consists of two or more computers that are linked in order to share resources Internet : is a global wide area network (WAN) used by billions of people every day. As with any other WAN, it consists of a number of local area networks (LANs) connected together. The internet is the infrastructure : means the basic physical and organizational structures and facilities. World Wide Web WWW : is a service that is made available by the internet. It provides access to webpages linked together using hyperlinks that allow users to easily open other webpages or resources. Webpages are documents which may contain text or other media. Webpages are stored on web servers and each page has an address known as a Uniform Resource Locator (URL). A web server is a computer dedicated to storing web pages securely and delivering them to users when requested. Like all devices connected to the internet, a web server will have an IP address. Network interface card/controller // NIC : the component in the computer that is needed to 5.1 The internet and the world wide web The Internet : The internet refers to the global network of computers and other electronic devices connected together through a system of routers and servers It is the infrastructure that allows us to send and receive information, including email, instant messaging, and file transfers The internet also provides access to other services such as online gaming, video streaming, and cloud computing The World Wide Web The world wide web, or simply the web, is a collection of websites and web pages that are accessed using the internet The web consists of interconnected documents and multimedia files that are stored on web servers around the world Web pages are accessed using a web browser, which communicates with web server to retrieve and display the content  5.1 The internet and the world wide web A uniform resource locator (URL): a text-based version of a web address is the address that is used in the web browser to request a resource (web page) from the world wide web. A URL contains - running from left to right: http(s) the domain name - the name of the website an area within that website - like a folder or directory the webpage name - the page that is being viewed For example: https://www.bbc.co.uk/bitesize/support https is the protocol www.bbc.com is the domain name stored on a DNS /bitesize/ is the folder structure leading to where the webpage is located support is the name of the requested webpage  5.1 The internet and the world wide web Web pages are typically created using three components : HTML, CSS and JavaScript. Hypertext Markup Language (HTML): is markup language used to create web pages. HTML pages are interpreted/rendered by a web browser. HTML tags are added to each element of content in order to provide meaning and context.,,………… Images, tables and hyperlinks are also included using HTML. Cascading Style Sheets (CSS) CSS is a presentation language. Its purpose is to provide a web browser with styling instructions for the HTML. CSS can be included directly in the HTML tags, in the head section of the HTML, or in an entirely separate document (CSS style sheet). CSS is a very powerful tool, enabling very complex and unique designs to be made possible. Example of CSS :p {color: blue} * Although it is entirely possible to make a website just using HTML, it would look bland and unappealing. To create web pages that are visually stunning and easy to use, we need to use CSS. Javascript (JS) is a scripting languages, primarily used on the Web. It is used to enhance HTML pages and is commonly found embedded in HTML code.  5.1 The internet and the world wide web Hypertext Transfer Protocol (HTTP) It is a secure protocol // hypertext transfer protocol secure It is a set of rules for data transmission It combines HTTP and SSL/TLS to transmit data It encrypts data for transmission Web Browser A web browser is a software program which allows the user to request and retrieve web pages (and other resources) from a webserver on the world wide web. The primary function of a web browser is to translate HTML code which is used to design webpages. Examples : Google Chrome , Internet Explorer , Mozilla Firefox, Opera , Microsoft Edge…… Functions : interprets/translates embedded scripting, for example JavaScript It provides security to the data and the resources that are available on the web using the secure methods. Receives web pages back from webserver. Manages protocols. Has a HOME page the ability to store a user’s favorite websites/pages keeps a history of the websites visited by the user Gives the ability to go backward and forward to websites opened. Manages/stores the cookies allowing use of multiple tabs  5.1 The internet and the world wide web Internet Protocol IP address : is the unique identification number given to every device that is connected to the internet. It represents the unique location on which you are connected to the internet, allowing devices all over the world to communicate with each other. IP addresses are similar to your postal address, you cannot expect to get letters to your home unless you have a unique way of identifying it from all the other homes. When connecting to the internet, you are assigned an IP address to use for your session. This is issued by your network or ISP. A dynamic IP address:It can be used to uniquely identify a device (on a network) and can be changed each time the device is connected to the network Domain Name Server/System DNS : The Domain Name System (DNS) is the phonebook of the Internet. Humans access information online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources. Each device connected to the Internet has a unique IP address which other machines use to find the device. DNS servers eliminate the need for humans to memorize IP  5.1 The internet and the world wide web TCP stands for Transmission Control Protocol :that enables application programs and computing devices to exchange messages over a network. It is designed to send packets across the internet and ensure the successful delivery of data and messages over networks. The TCP/IP model (suite) is the default method of data communication on the Internet. enables the accurate and correct transmission of data between devices. It performs Packet switching. Retrieval and location of web pages 1. The user opens their browser and types the URL and the browser asks the DNS server1 for the IP address 2. In case DNS server 1 can't find the IP address in its database it sends out a request to DNS server2 3. DNS server2 finds the IP address of the URL , it sens it back to DNS server1 which now puts the IP and URL into it’s database. 4. The IP address is then sent back to the user’s computer. 5. The computer now sets up a communication with the website server (SSL/TLS starts to authenticate the website ),and the required pages are downloaded. 6. HTML files are sent from the website server to the computer. 7. The browsere interpets the HTML and displays the information on the user’s computer  5.1 The internet and the world wide web Cookies are small text files. They are stored on a user’s computer by a web browser, at the request of the web server. A cookie is limited to a small amount of data and can only be read by the website that created it. Cookies are generally used to: Store and maintain user preferences for a website Determine who are new and returning visitors Track user behavior (analytics) Store items in shopping baskets Store log-in details Help advertisers show relevant targeted website adverts Cookies can be used to store a customer’s credit card details Cookies are not programs. They cannot perform any operations; they are not viruses or malware. Types of cookies : Session Cookies Session cookies are temporarily stored in RAM and not actually saved to your secondary storage. They are automatically deleted once you have finished your session browsing a website and you close the web browser. Online shopping baskets will usually make use of session cookies.  Digital currency Digital currency : Refers to any means of payment that exists in a purely electronic form. Digital money is not physically tangible like a dollar bill or a coin. It is accounted for and transferred using online systems. One well-known form of digital money is the cryptocurrency Digital money is exchanged using technologies such as smartphones, credit cards, and online cryptocurrency exchanges. In some cases, it can be converted into physical cash through the use of an ATM. Digital currency relies on a central banking system , the problem with centralization is confidentiality Cryptocurrency : A cryptocurrency or crypto, is a virtual currency secured by cryptography(encryption). Traditional digital currencies are regulated and controlled by central banks  Digital currency – BlockChain BlockChain: is a decentralized database , contains all transactions of networked members (digital ledger). The blockchain consists of number of interconnected computers that are not connected to a central server. When new transaction takes place all the networked computer get a copy of the transaction. A blockchain collects information together in groups, known as blocks. Blockchain is an especially promising and revolutionary technology because it helps reduce security risks Blockchain is used in many areas : cryptocurrency, smart contracts , research, politics, education ….. https://youtu.be/SSo_EIwHSd4  Digital currency – BlockChain Block : Every chain consists of multiple blocks , when new transaction takes place a new block is created ,each block has three basic elements: The data in the block: name of the sender , receiver, amount of money The hash value : a unique value created by an algorithm for each block which acts as fingerprint. Previous hash value: this points to previous block(transaction ) in the chain. The hash is like a fingerprint, and it's just a long combination of numbers and letters. If someone tries to tamper with a block, this will change its hash, which then will change the hash of all succeeding blocks in the chain. Because this happens, it sets off an immediate alarm among every single node in the blockchain , they'll reject this change as invalid, and the network will self-heal. Timestamp : when create new block is created a new hash value will be created this value contains timestamp which identifies when an event takes place Genesis block : this is block ‘1’ doesn’t contain previous hash value  Digital currency – BlockChain Peer-Peer(P2P) network :is a decentralized network that consists of a group of devices (users) connected together to share and store information with each other. Each node or device acts as an individual server. when a new transaction is started a new block is created it will be sent each computer (nodes) in the network to be checked before being added to the chain. If new network user is created a copy of everything in the blockchain will be sent to it. Proof of Work POW Proof of Work requires the people who own the computers in the network to solve a complex mathematical problem to be able to add a block with hash value to the chain. Solving the problem is known as mining, and ‘miners’ are usually rewarded for their work in cryptocurrency. miners are competing against each other to create hashes for blocks in the blockchain network. This particular protocol is called Proof-of-Work. Proof-of-work makes sure it takes enough time(10 minutes) to create the block and the hash value, so the process is slowed down which prevent hackers.  Digital currency – BlockChain Blockchain Transaction Process: Step 1) Some person requests a transaction. The transaction could be involved cryptocurrency, contracts, records, or other information. Step 2) The requested transaction is broadcasted to a P2P network with the help of nodes. Step 3) The network of nodes validates the transaction and the user’s status with the help of known algorithms. Step 4) Once the transaction is complete, the new block is then added to the existing blockchain by miners and proof-of-work. In such a way that is permanent and unalterable.  Digital currency – Adv,disadv Advantages : Fast Transfer and Transaction Times No Physical Manufacturing Required Cheaper Transaction Costs Disadvantages Storage and Infrastructure Issues Hacking Potential  Cyber Security Cybersecurity is the protection of internet-connected systems such as hardware, software and data from cyberthreats Cyberthreats : – brute-force attack – data interception – distributed denial of service (DDoS) attack – hacking – malware (virus, worm, Trojan horse, spyware, adware, ransomware) – pharming – phishing – social engineering  Cyber Security - brute-force attack A brute force attack involves ‘guessing’ username and passwords to gain unauthorized access to a system. Brute force is a simple attack method and has a high success rate. Combinations are repeatedly entered until correct password is found and can be carried out manually or automatically by software Effects : Steal/view/access data Delete data Change data Lock account // Encrypt data Damage reputation of a business How to Prevent Brute Force Password Hacking 1. To protect your organization from brute force password hacking, enforce the use of strong passwords. Passwords should: Never use information that can be found online (like names of family members). Have as many characters as possible. Combine letters, numbers, and symbols. Be different for each user account. Avoid common patterns ex.123456,000000,……  Cyber Security – Data Interception Data interception : Where data is intercepted during transmission. This is done using software called a packet sniffer, which examines data packets as they are sent around a network, or across the internet. The information gathered is sent back to a hacker. Wi-Fi (wireless ) data interception can be carried out by Wardriving ( also called Access Point Mapping) : Wardriving : The act of locating and using wireless internet connections illegally; it only requires a laptop (or other portable device), a wireless network card and an antenna to pick up wireless. signals Effects: It is possible to steal a user's internet time/ allocation by downloading large files (e.g. movie files) It is possible to hack into the wireless network and steal a user's password and other personal details ways of protection : Use of Wired Equivalent Privacy (WEP) which uses encryption  Cyber Security – distributed denial of service (DDoS) attack Distributed denial of service attack (DDoS): is an attempt of preventing users from accessing part of a network. This is usually temporary but may be a very damaging. Using : A bot/ is a device that is infected by malware to carry out commands under the remote control of the attacker. A botnet (short for “robot network”) is a network of computers infected by malware that are under the control of a single attacking. How? Malware downloaded to several computers turning it into a bot/zombie creating a network of bots/zombies Third party/hacker initiating the attack Bots send requests to a web server at the same time The web server fails due to the requests  Cyber Security – distributed denial of service (DDoS) attack Why : Revenge To affect a company’s reputation Entertainment value To demand a ransom to stop it To test a system’s resilience They may want to punish the company Distributed denial of service attack (DDoS) Signs. Slow network performance (opening files or accessing certain websites) Unavailability or inability to access particular websites Large amounts of spam mail reaching the user’s email account. An individual user or a website can guard against these attacks to some degree by: Using an up-to-date malware/virus checker Setting up a firewall/proxy server to restrict traffic to and from the internet server or user’s computer Applying email filters to manage or filter out unwanted traffic or spam emails  Cyber Security – Hacking Hacking : is the act of gaining illegal access to a computer system without the user’s permission. Effects : This can lead to identity theft or gaining personal information Data can be deleted, changed or corrupted Ways of protection : Firewalls Use of strong passwords and user ids Use of anti-hacking software Introduce Ethical Hacking. Note: use of encryption won't stop hacking - it simply makes the data useless to the hacker but they can still delete or corrupt the data  Cyber Security – Malware Malware is short for malicious software. Malware is the name given to any software that could harm a computer system, interfere with a user's data, or make the computer perform actions without the owner's knowledge or permission. Some forms of malware : Viruses. Worms. Trojans. Spyware. Adware. Ransomware.  Cyber Security – Malware : Viruses A computer virus is a piece of software that can 'infect' a computer (install itself) and copy itself to other computers, without the users knowledge or permission. Viruses need Active Host program on the target computer before they can actually run and cause harm Effects : intention of : Deleting files , Corrupting files , Causing a computer to malfunction How does a computer get a virus? Sharing music, files, or photos with other users Visiting an infected website Opening spam email or an email attachment Downloading free games, toolbars, media players and other system utilities Installing cracked software applications How Can a Computer Be Protected from Viruses? There are some simple things you can do to help prevent a virus infecting your computer: Install anti-virus software and keep it up-to-date Install anti-malware software Never download and install software from the Internet unless you are certain it is from a source you can trust Don’t open e-mail attachments unless you have scanned them. Don’t click links in websites that seem suspicious (if a site is offering prizes / free stuff / etc. be suspicious!) If someone gives you a memory stick or CD-ROM, run a virus scan on it before opening any  Cyber Security – Malware : Worms A computer worm is a computer program that makes lots of copies of itself, like a computer virus. The main difference between the two is that a computer virus attaches itself to another computer program, but a worms work by itself don’t need Active host program. virus won’t harm your system unless you run it. a worm doesn’t need a host system or user action to spread. A worm will typically spread across a network through your local area network or internet connection. Effects : delete files on a computer, or send e-mails to everyone the owner has in their address book How Can a Computer Be Protected from worms? Install anti-virus software and keep it up-to-date Install anti-malware software Back up regularly. Don’t open e-mail attachments unless you have scanned them. Don’t click links in websites that seem suspicious (if a site is offering prizes / free stuff / etc. be suspicious!)  Cyber Security – Malware : Trojan horse A Trojan Horse Virus is a type of malware that downloads onto a computer as a trusted program. it is a type of malware that typically gets hidden as an attachment in an email or a free-to-download file, then transfers onto the user’s device. Once downloaded, the malicious code will execute the task the attacker designed it for such as backdoor for the hackers to access the device , or install harmful software such as spyware …. Effects : the presence of a Trojan include computer changing settings, a loss in computer performance, or unusual activity taking place. Ways of protection: Don’t ignore software updates. Back up regularly. Be wary of email attachments. Don’t click on questionable email links. Be careful what you download.  Cyber Security – Malware : Spyware Spyware is part of the malware family, spyware is software that gathers information about users and their online activities without their knowledge and send them to the creator. How does the computer get infected by Spyware : − The user could have been sent an email with an attachment / link containing the spyware − The user could have clicked a link on an untrusted website − When the attachment / link was clicked the spyware was downloaded onto the user’s computer − The spyware recorded all the key logs from the user’s keyboard − The recorded key logs were sent back to the creator of the spyware − The key logs were analysed − A common pattern / word in the key logs could have allowed a password to be identified Effects : This sensitive information is sent back to the creator and used for criminal purposes. Spyware is hard to detect and can gather lots of private data before finally being detected. The software is able to install other spyware, read cookie data and also change a user’s default web browser Spyware also affects network and device performance, Ways of slowing down daily user activities. protection: Information such as : antivirus software with spyware protection. Login information — passwords and usernames use a pop-up blocker or avoid clicking pop-up ads. Account PINs or Credit card numbers keep your computer or mobile operating systems Monitored keyboard strokes / called keylogging Tracked browsing habits updated. Don't open unsolicited or suspicious email attachments email addresses  Cyber Security – Malware : Spyware Ways of protection: antivirus software with spyware protection. use a pop-up blocker or avoid clicking pop-up ads. keep your computer or mobile operating systems updated. Don't open unsolicited or suspicious email attachments from unknown sender Don't click links in text messages from unknown senders. Firewall To enter the login details use : Drop down boxes Onscreen/virtual keyboard Biometrics. no password entered to be gathered Random/select values requested from password this means that full password cannot be obtained (in a single login)  Cyber Security – Malware : Adware Adware, is software that displays unwanted advertisements on your computer. It could redirect a user’s browser to a website that contains advertisements, it could appear in the form of pop-ups, or it could appear in the browser’s toolbar and redirect search request. Adware normally comes in software/programs that you download from the internet. Protection ways : Use antivirus software. Perform updates. Only download apps from known app stores. Don’t click on pop-up ads. Beware of phishing.  Cyber Security – Malware : Ransomware Ransomware is a form of software that is downloaded in the user device and encrypts a victim's files or lock the computer. The attacker then demands a ransom from the victim to restore access to the data upon payment. Users are shown instructions for how to pay a fee to get the decryption key. Ransomware is often spread : through phishing emails that contain malicious attachments when a user unknowingly visits an infected website and then malware is downloaded and installed without the user’s knowledge. through social engineering By trojan horse Protection ways : data backup and recovery plan for all critical information. Keep your operating system and software up-to-date Maintain up-to-date anti-virus software Restrict users’ ability (permissions) to install and run unwanted software applications, Do not follow untrusted Web links in emails  Cyber Security – pharming Pharming : malicious software will be downloaded onto your hard drive. This malicious software is designed to redirect certain website requests to a fake website looks very similar to a genuine. How ? Using pop-up links , or DNS cache poisoning. DNS cache poisoning : Every time a user types in a URL, their browser contacts the DNS server; the IP address of the website will then be sent back to their browser. If the DNS server itself has been infected , the DNS cache poisoning changes the real IP address values to those of the fake website; consequently, the user's computer will be connected to the fake website. Why : gaining personal data, such as bank details, and identity theft. How to protect yourself against pharming Choose a reputable internet service provider (ISP). Only follow links that begin with HTTPS Don’t click on links or open attachments from unknown senders. Check URLs spelling.  Cyber Security – Phishing Phishing occurs when a attacker send out legitimate,- looking email to user, The email may contains links or attachments that take the user to a fake website; or they may trick the user into responding with personal data (for example, bank account details or credit/debit card details). The key point is that the recipient has to initiate the link or attachments. Ways to help prevent phishing attacks: it is important not to click on any emails links unless totally certain that it is safe it is important to run anti-phishing toolbars on browsers (this includes tad and mobile phones) since these will alert the user to malicious websites contained in an email always look out for https or the green padlock symbol in the address bar Ensure up-to-date browser Be aware of pop-up and use browser to block them  Cyber Security – Social engineering Social engineering relies on manipulating and deceiving people into providing confidential or personal data that can be used in criminal activity such as identity theft and fraud, and hacking into computers systems or networks. Social engineering can take many different forms. Instant messaging: Malicious links are embedded into instant messages; for example, an important software upgrade Scareware (for example, fake anti-virus that looks real): This is often done using a pop-up message that claims that the user’s computer is infected with a virus; the user is told they need to download the fake anti-virus immediately Emails/phishing scams: The user is tricked by the apparent genuineness of an email and opens a link in the email; this redirects their browser to a fake website Baiting : The cybercriminal leaves a malware-infected memory stick somewhere where it can be found; the finder picks up the memory stick and plugs it into their computer Phone calls : For example, a so-called IT professional calls the user on their mobile claiming their device has been compromised in some way; the user is advised to download some special software that allows the cybercriminal to take over the user's device giving them access to personal information (relies on fear)  Cyper security- keep data safe from security threats access levels anti-malware including anti-virus and anti-spyware authentication (username and password, biometrics, two-step verification) automating software updates checking the spelling and tone of communications and the URL attached to a link firewalls privacy settings proxy-servers secure socket layer (SSL) security protocol Cyper security- keep data safe from security threats-access levels Access levels : most systems have a hierarchy of access levels depending on a person's level of security; this is usually achieved using a username and password levels of access are important : When using databases, it is essential to determine who has the right to read, write and delete data Another area where access levels are very important is in social networks (such as Facebook); with this type of application, there are usually four access levels: public access , friends, custom and data owner users are allowed to use privacy settings Cyper security- keep data safe from security threats-Anti-Malware Anti-malware : has two types Anti-Virus Software and anti-spyware Anti-Virus Software: An anti-virus is a software that scans your system for any viruses and terminates them, scan new viruses from entering and protects your system from any more harm. The anti-virus software should be active all the time to deal with the viruses at earliest. It can also scan your emails, new disks connected to your system as well as the new programs you download from the internet. It is also capable of isolating infected files to protect other files from being corrupted, which either delete the files or ask the user to take the action Must be up-to-date Cyper security- keep data safe from security threats-Anti-Malware Anti-malware : Anti-spyware Is a software detects and removes spyware programs installed illegally on a user's computer system. anti-spyware features are: detect and remove spyware already installed on a device. prevent a user from downloading spyware encrypt files to make the data more secure in case it is ‘spied' on encryption of keyboard strokes to help remove the risk posed by the keylogging aspects of some spyware blocks access to a user's webcam and microphone scans for signs that the user's personal information has been stolen and warns the Cyper security- keep data safe from security threats- Authentications Authentication : Authentication is the process of verifying who a user claims to be. includes username and password, biometrics, two-step verification. 1. Username and passwords : Username and password combination is the most popular authentication mechanism, and it is also known as password authentication. If you enter a valid combination the access will be given to your account. The first way to protect the account is by enforcing strong password.Strong passwords used for authenticating can withstand brute force attacks but are useless against attacks like phishing and keylogger software or password stuffing. Change the password on regular basis Passwords should always be stored using best practices, such as encryption. Many systems ask for a new password to be typed in twice as a verification check To help protect the system, users are only allowed to type in their password a finite number of times before the system locks the user out. When using an online company, if a user forgets their password or they need Cyper security- keep data safe from security threats- Authentications 2. Two-Factor Authentication. : is a security system that requires two separate forms of identification in order to access something. The first factor is a password and the second commonly includes a text with a code sent to your smartphone. 3. Biometrics Uses biological data ,relies on the unique characteristics of human beings; include: fingerprint scans retina scans face recognition voice recognition A biometric password is more secure than a PIN because : A biometric password cannot be guessed It is very difficult to fake a biometric password A biometric password cannot be recorded by a keylogger/spyware A perpetrator cannot shoulder surf to see a biometric password Cyper security- keep data safe from security threats- Authentications Biometrics Cyper security- keep data safe from security threats- Automatic system updates Automatic software updates These updates are vital since they may contain parts that : update the software security (to protect against malware) improve the software performance (for example, removal of bugs and addition of new features).  Cyper security- keep data safe from security threats- checking the spelling and tone of communications and the URL attached to a link Check out the spellings in the email and in the links; professional, genuine organizations will not send out emails which contain spelling or major grammatical errors (for example, Amazzon.com) Carefully check the tone used in the email message; if it is rushing you into doing something or if the language used seems inappropriate or incorrect, then it could be a phishing email or worse. Read the URL carefully. Look for minor differences in the URL text you see and what you expect. HTTPS or pad lock. Always look to verify you have an HTTPS connection Website privacy policy : Look for it and review it before sharing your information Cyper security- keep data safe from security threats- Privacy setting Web browser and online applications are paying attention to many different controls and settings such as : Access levels settings in the browser involve ways for the servers to identify and handle Internet traffic, where more precise settings can help users to identify sites that are safe or not. Auto-install updates Don't allow automatic downloads Block unwanted pop-ups Restrict access to your location, camera, and microphone. Don't save passwords Using a master password :If you do save passwords, set a Master password so they aren't easily accessible to anyone with access to the system. Cyper security- keep data safe from security threats- Firewall Firewalls : https://www.youtube.com/watch?v=kDEX1HXybrU a firewall can be either software (installed on a computer; in some cases, this is part of the operating system) or hardware (called Gateway). It sits between the user’s computer and an external network (e.g. the internet) and filters information in and out of the computer. The firewall can be a hardware interface which is located somewhere between the computer (or internal network external link) and the internet connection. In this case, it is referred to as a GATEWAY.  Cyper security- keep data safe from security threats- Firewall Tasks carried out by a firewall include: Examining the ‘traffic’ between the user’s computer (or internal network) and a public network (e.g. the internet) Traffic means : is the amount of data moving across a network at a given point of time Checking whether incoming or outgoing data meets a given set of criteria /rules If the data fails the criteria, the firewall will block the ‘traffic’ and give the user (or network manager) a warning that there may be a security issue Logging all incoming and outgoing ‘traffic’ to allow later interrogation by the user (or network manager) Criteria can be set to prevent access to certain undesirable sites; the firewall can keep a list of all undesirable IP addresses Helping to prevent viruses or hackers entering the user’s computer (or internal network) Warning the user if some software on their system is trying to access an external data Cyper security- keep data safe from security threats- Firewall However, there are certain circumstances where the firewall can’t prevent potential harmful ‘traffic’ (all users have access accounts given by the firewall ): It cannot prevent individuals, on internal networks, using their own modems to bypass the firewall. Employee misconduct or carelessness(give the password to someone else) cannot be controlled by firewalls (for example, control of passwords or use of accounts) Users on stand-alone computers can choose to disable(disconnect the computer) the firewall, leaving their computer open to harmful ‘traffic’ from the internet. Cyper security- keep data safe from security threats- Proxy server PROXY SERVERS : act as an intermediate between the user and a web server. Firewalls can block ports and programs that try to gain unauthorized access to your computer, while proxy servers basically hide your internal network from the Internet. It works as a firewall in the sense that it blocks your network from being exposed to the Internet by redirecting Web requests when necessary. Functions of proxy servers include: Allowing the internet ‘traffic’ to be filtered; they can block access to a website if necessary (similar type or reaction as a firewall) By using the feature known as a CACHE, they can speed up access to information from a website. Cache is a memory that store the webpages that were visited by the users , so for next visit of the user the proxy server takes the page from the cache , for faster access. Keeping the user’s IP address secret(by masking the IP address) – this clearly improves security. To act as intermediary between browser and web server to filter/examine/monitor traffic to the web server to help stop malicious traffic to the web server To cache frequently viewed web pages to allow faster response time for requests to reduce the number of requests the server needs to process To help prevent DoS by stopping the webserver being overloaded with requests  how data can be damaged accidentally Data can be damages accidentally : main protection way is backup Power surge/loss (damages hardware) : Use a UPS to protect your data Water can be spilled on the device : Don’t have water near the device , and Keep device in a waterproof box when not is use Fire can destroy device : Use electrics safety ,and Keep device in a fireproof box when not is use Data is accidentally deleted : backup , Add verification method for data deletion , and Set access levels for data to limit who can delete the data Incorrect use of storage device : Making sure device is ejected before removing Physical damage to hardware // hardware failure : Correct care and maintenance of hardware Cyper security- keep data safe from security threats- SSL A protocol is a set of rules and guidelines for communicating data. Rules are defined for each step and process during communication between two or more computers. Networks have to follow these rules to successfully transmit data (allows data to be sent and received securely over the internet.). SECURE SOCKETS LAYER (SSL) : Is a type of protocol allows data to be sent and received securely over the internet. SSL is being applied when https or the small padlock is in the status bar at the top of the screen. http without using of SSL (no encryption) https(s stands for secure) : https using SSL (encryption) When a user logs onto a website, SSL encrypts the data – only the user’s computer and the web server are able to make sense of what is being transmitted. An SSL certificate ensures identity protection and tightens network security. SSL Certificate : An SSL certificate is a form of digital certificate which is used to authenticate a website. It is a validation and encryption tool, part of the HTTPS protocol. It contains information about the website with the encryption key to activate padlock or Cyper security- keep data safe from security threats- SSL Steps of SSL : Cyper security- keep data safe from security threats- SSL Examples of where SSL would be used: online banking and all online financial transactions online shopping/commerce when sending software out to a restricted list of users sending and receiving emails using cloud storage facilities intranets and extranets (as well as the internet) Voice over Internet Protocols (VoIP) when carrying out video chatting and/or audio chatting over the internet used in instant messaging when making use of a social networking site. Cyper security- keep data safe from security threats- TLS TRANSPORT LAYER SECURITY (TLS) : TLS is a form of protocol that ensures the security and privacy of data between devices and users when communicating over the internet It is the recent security system. It is essentially designed to provide Encryption: hides the data being transferred from third parties. Authentication: ensures that the parties exchanging information are who they claim to be(Authenticate the identity of the server using the server's TLS certificate) Integrity: verifies that the data has not been forged or tampered with. A primary use case of TLS is encrypting the communication between web applications and servers, such as web browsers loading a website , emails…….. Cyper security- keep data safe from security threats- TLS TLS is formed of two layers(SSL one Layer) : Record Layer : this part of the communication can be used with or without encryption (it contains the data being transferred over the internet). Handshake Layer : this permits the website and the client (user) to authenticate (using website’s certificate which contains the encryption key) each other and to make use of encryption algorithms (a secure session between client and website is established). Why is SSL still used? : because only the most recent web browsers support both SSL and TLS. A TLS connection is initiated using a sequence known as the TLS handshake. When a user navigates to a website that uses TLS, the TLS handshake begins Cyper security- keep data safe from security threats- TLS Same steps of SSLwill be used for TLS Client/browser requests secure connection to server Client/browser requests the server to identify itself Server provides a digital certificate Client/browser validates the certificate Client/browser send signal bac to server (to begin transmission) Session caching can be used A session key is generated Encryption method is agreed // data is encrypted