internet and its uses

• internet


  -it is basically a worldwide collection of interconnected networks

  -The internet is actually a concept rather than something tangible (that is, something we can touch).

  -relies on a physical infrastructure that allows networks and individual devices to connect to other networks and devices
• world wide web(WWW)

  -a part of the internet that users can access using web browser software.

  -a way of accessing information using the internet
• uniform resource locators(URL)


  -text addresses that are used to access websites
• web browser


  -Web browsers are software that allow users to access and display web pages on their device screens

  -. They interpret HTML from websites to display content like videos, images, and text.

  -Common features include a home page, storing bookmarks, keeping a history of visited sites, navigating forwards/backwards, using multiple tabs, utilizing cookies, hyperlinks for navigation, storing data as a cache, supporting JavaScript, and having an address bar.
• Hypertext transfer protocol (http)


  -a set of rules that must be obeyed when transferring files across the internet

  -->in some form of security it changes to https where "s" stands for secure and indicates a more secure way of sending or receiving data across network
• DOMAIN NAME SERVER(DNS)

  When you enter a URL, the browser asks the DNS server for the website's IP address. If not found, it requests another DNS server. Once found, the IP address is sent back, stored, and used to set up communication with the website server. HTML files are then downloaded, interpreted by the browser, and displayed on your computer.

  -To access a website, your browser needs the server's IP address.
• COOKIES

  -small files or code stored on a user’s computer.

  • Each cookie contains pairs of (key, data) values, like (surname, Jones) or (music, rock). When a user revisits a website, it checks for previously set cookies. If found, the browser reads the cookie, containing information on user preferences such as language, currency, and past browsing activity. Cookies enable user tracking and preference maintenance, allowing websites to customize content based on individual users
• types of cookies session cookie

  1-Session cookies:

  used when making online purchases, store a user's items in a virtual shopping basket. These cookies are in temporary memory on the computer, don't collect information, and don't personally identify a user. They disappear when the browser is closed or the website session ends.
• persistent cookie (permanent)


  Persistent cookies remember login details and are stored on a computer's hard drive until they expire or are deleted. They stay even after the browser is closed, saving time by avoiding repeated logins. Some may store personal info, but only with user consent, and legitimate sites encrypt this data for security. Laws in many countries aim to deactivate these cookies after six months. They efficiently carry data between website sessions, avoiding the need to store large amounts of data on the web server.
• Digital currency


  -exists purely in a digital format.

  -has no physical form unlike conventional fiat currency (for example, $, £, €, and ¥).

  -digital currency can be transferred between various accounts when carrying out transactions. It has made it possible to bank online or via a smartphone app
• crypto currency

  Cryptocurrency uses cryptography to track transactions and was created to solve issues linked with centralized digital currency.

  • Traditional digital currencies are regulated by central banks and governments, controlling transactions and exchange rates. Cryptocurrency, however, operates without state control, with rules set by its community.
  • Unlike other digital currencies, cryptocurrency transactions are public, allowing tracking of all transactions and monitoring the total money in the system.
  • Cryptocurrency operates within a secure blockchain network
• block chain

  Blockchain is a decentralized database where all network transactions are stored. It's different from traditional systems because there's no central server. When a new transaction happens, all computers in the network get a copy, making it secure against hacking.Each transaction creates a new block with data (sender, recipient, amount), a unique hash (like a fingerprint), and a previous block reference. This ensures each block is unique. Changes to one block can invalidate subsequent ones, preventing tampering.
• cyber security

  -keeping data safe is our number 1 priority
• cs1(cyber security)

  -brute force attack:If a hacker wants to guess your password, they might use a brute force attack, systematically trying different combinations of letters, numbers, and symbols until they find the right one. This method lacks sophistication. To reduce the number of attempts 1.Check if the password is common (like 123456, password, qwerty, 111111, or abc123). 2. If not in the common list, use a strong word list, containing many words, to speed up the process. with these methods, it still takes hours to find password. Longer and complex passwords are harder to crack.
• CS2

  data interception : Data interception is stealing info from wired or wireless communication. In wired networks, hackers use packet sniffers, and Wi-Fi interception, like wardriving, captures data using laptops or smartphones. Encryption helps, so use WEP and a firewall. Secure your router with strong passwords. Avoid using unencrypted Wi-Fi in public to keep your data safe. Stay vigilant against these tactics.
• cs3

  Denial of service: A DoS attack blocks network or server access temporarily, affecting email, websites, or online services. Attackers flood the network, overwhelming the server. In a DDoS attack, spam comes from many computers, making it hard to stop.For instance, attackers might fill an email account with spam, preventing the user from getting real emails due to data limits set by internet service providers. To defend against these attacks, individuals or websites can use updated malware checkers, set up firewalls, and apply email filters.
• cs4

  Hacking is the unauthorized access to computer systems, which can result in identity theft or misuse of personal information. Hackers may delete, alter, or corrupt data. While encryption can make data meaningless to hackers, it doesn't prevent other harmful actions. To deter hacking, use firewalls, user names, strong and regularly changed passwords, and employ anti-hacking and intrusion-detection software.

  Malicious hacking is illegal, but ethical hacking involves authorized individuals testing security measures and assessing computer systems' resilience to hacking attacks.
• malware


  -one of the biggest risks to the integrity and security of data on a computer system
• malware 1 (includes):

  1.viruses:Viruses are programs that replicate with the goal of deleting or corrupting files, causing computer malfunctions. They need an active host program or an already infected operating system to run and cause harm. Viruses often spread through email attachments, infected websites, or downloaded software. To protect against viruses, avoid opening emails from unknown sources, refrain from installing non-original software, and always use an up-to-date virus scanner.
• malware2


  worms

  
• malware3


  trojan horse

  
• malware 4


  spyware

  
• malware 5


  Adware

  
• malware 6

  ransom ware:

  -holds data hostage

  -programs that encrypt the data on a user’s computer; a decryption key is sent back to the user once they pay a sum of money (a ransom); they are often sent via a Trojan horse or by social engineering
• phishing 


  -when a cybercriminal sends out legitimate-looking emails to users. The emails may contain links or attachments that, when initiated, take the user to a fake website; or they may trick the user into responding with personal data

  -appears to be genuine coming from a known bank or service provide
• How to avoid phishing

  1. Stay updated on new phishing scams with regular security training.
  2. Don't click on email links unless you're sure they're safe; watch out for generic greetings like "Dear Customer."
  3. Use anti-phishing tools on your devices.
  4. Always check for "https" or the green padlock symbol in the address bar.
  5. Keep passwords updated and monitor online accounts.
  6. Keep your browser and firewall up-to-date to prevent hacking.
  7. Avoid pop-ups and close them using the "x" in the corner if they appear.
• spear phishing 


  where

  the cybercriminal targets specific individuals or companies to gain access to sensitive financial information or industrial espionage – regular phishing is not specific regarding who the victims are.
• Pharming 


  malicious code installed on a user’s computer or on an infected website. The code redirects the user’s browser to a fake website without the user’s knowledge. Unlike phishing, the user doesn’t actually need to take any action for it to be initiated. The creator of the malicious code can gain personal data, such as bank details, from the user. Often the website appears to come from a trusted source and can lead to fraud and identity theft.
• Why does pharming pose a threat to data security?

  pharming redirects internet users to a fake or malicious website set up by, for example, a hacker; redirection from a legitimate website to the fake website can be done using DNS cache poisoning

  DNS:domain name server
• 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. However, DNS cache poisoning changes the real IP address values to those of the fake website; consequently, the user’s computer will connect to the fake website
• how to save from pharming

  » Use of anti-virus software can detect unauthorised alterations to a website address and warn the user of the potential risks.» However, if the DNS server itself has been infected (rather than user’s computer) it is much more difficult to mitigate the risk.» Many modern browsers can alert users to attacks. It is very important to check the spelling of websites to ensure the web

  address used is correct.» As with phishing, use of https or the green padlock symbol in the address

  for more on URLs, IP addresses and DNS bar is an additional form of defence.
• Social engineering


  when a cybercriminal creates a social situation that can lead to a potential victim dropping their guard. It involves the manipulation of people into breaking their normal security procedures and not following best practice.
• Social engineering involves

  Malicious links can be found in instant messages, like fake software upgrades or scary pop-ups claiming a virus infection. Phishing emails appear genuine but lead to fake websites. Cybercriminals may also leave infected USB drives in public places to tempt users into plugging them in out of curiosity. Another tactic involves fake IT professionals calling users, asking them to download software that gives the criminal access to their device.
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• Access levels


  In computer systems, different users have different levels of access. For example, in a hospital, cleaners don't have access to patient data, but doctors do. Access is managed with usernames and passwords. In databases, users can only read, write, or delete data based on their access level. Social networks like Facebook have four access levels: public, friends, custom, and data owner, controlled by privacy settings.
• Anti spyware


  -detects and removes spyware programs installed illegally on a user’s computer system . Based on:rules – in this case, the software looks for typical features which are usually associated with spyware thus identifying any potential security issues

  » file structures – in this case, there are certain file structures associated with potential spyware which allows them to be identified by the software.
• Features of spyware

  detect and remove spyware already installed on a device » prevent user from downloading spyware » encrypt files to make data more secure in case it is ‘spied’ on » encryption of keyboard strokes to help remove the risk posed by the key-logging aspects of some spyware

  » blocks access to user’s webcam and microphone (the software stops spyware taking over the control of user’s webcam and microphone which can be used to collect information without user’s knowledge) » scans for signs that user’s personal information has been stolen and warns the user if this has happened.
• Authentication


  » something you know (for example, a password or PIN code) » something you have (for example, a mobile phone or tablet) » something which is unique to you (for example, biometrics).
• Authentication includes

  Authentication methods include passwords and usernames, used to protect data and systems. Passwords should be strong, changed regularly, and not easy to guess. Biometrics, like fingerprints on phones, can also be used. To protect passwords:

  Use anti-spyware software.

  Change passwords regularly.

  Avoid simple passwords.

  Strong passwords have letters, numbers, and symbols.

  Passwords are usually hidden when typed.

  Systems limit login attempts.

  Users may reset passwords via email.

  • Usernames add extra security.
• Biometrics 


  use of unique human characteristics to identify a user as a form of authentication