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  • Key Stage 3 Python | Turtle | CSNewbs

    Python - Iteration For Loops Editor Execute A for loop is a count controlled loop. ​ It repeats for a certain number of times as stated in the range brackets. ​ The first number (1) states the number to start on . ​ The second number is an exclusive end . This means it actually finishes on the number before . (11 will end on 10). You need a colon at the end of the loop line . ​ Each line to be repeated must be indented (press the tab key). ​ You can use the loop number within the loop itself. 1. Write a for loop to print your name 8 times . (Count it to double-check it prints eight times.) ​ 2. Use a for loop to print each number between 10 and 50 . ​ 3. Use a for loop from 1 to 10 . Print the 3 times table by multiplying number by 3 underneath the loop. ​ 4. Ask the user to input a whole number (call it num1 ). Write num1 in your range brackets to repeat any message that many times. 5. Ask the user to input a whole number (call it num1 ) and then input a word . Print the word by the number they entered . (Hint: Use num1 in the range.) ​ 6. Delete your code and copy these 3 lines: ​ #Delete the space after the colon for number in range(0,21,2):​ print(number) ​ What happens when you run this code? ​ 7. Use Q6 to help you print 0 to 100 , going up in 5s . Think about the 3 values you need in the range brackets. ​ 8. Use Q6 to help you print 100 down to 0 , backwards by 1 . Think about the 3 values you need in the range brackets. Tasks While Loops Editor Execute A while loop is a condition controlled loop . ​ While loops repeat as long as the condition is true . As soon as the condition becomes false , the loop will end . 1. Change the program in the editor to repeat the loop while a number is not equal to 33 . ​ 2. Make a new while loop that asks the user to enter a whole number . While the number is less than or equal to 1000 , keep repeating. ​ 3. Make a new while loop for while a colour is not equal to purple (or any colour you want). Ask the user to enter a colour inside of the loop . Don't forget to set colour to "" before you start. ​ 4. Edit your colour program to count how many guesses were made. Make a new variable called count and set it to 0 at the start of the program. Increase it by 1 in the loop, using count = count + 1 . 5. While a total is less than 100 , ask the user to input a decimal number . When it is over 100 , print ‘COMPUTER OVERLOAD’ . You need a variable called total . Increase the total each time with total = total + number . Don't forget to start it at 0 . Tasks != means ‘not equal to ’. The loop below will repeat as long as the password is not equal to “abc123” . Any variable you use in your condition must have a value first . You can’t check for your password if it doesn’t exist. That’s why I have written password = “” , to give password a value before we check it .

  • Scams & Staying Safe | Key Stage 3 | CSNewbs

    Scams & Staying Safe Part 1: Phishing Scams A phishing scam is when an attacker will send you an email pretending to be someone you trust . They are trying to get your username, password or other sensitive information . What does a phishing email look like? A phishing email might be sent from a long, unrecognisable email address . A phishing email might contain spelling mistakes , so look carefully. An attacker might not know your name , so they will use your email address. Check any links carefully , if it looks suspicious, don't click it. Phishing emails try to rush you into making a silly decision. Don't panic and read the email carefully. Part 2: Secure webpages When you are browsing the web , you should stick to websites that you know and trust. Don't click on any links that you don't recognise , especially from strangers . How do i know a web page is secure? HTTP is a protocol (set of rules) for displaying a web page . ​ If the web address at the top of your web browser starts with HTTP then it is not secure . ​ Do not enter any personal information on an insecure web page. HTTPS is a protocol (set of rules) for displaying a secure web page. If you see a padlock in the address bar of your web browser then you know it is safer to enter information . Part 3: Strong passwords Your passwords must be secure so they cannot be broken easily. How to choose a strong password: ********* Passwords should be more than at least 8 characters long. Passwords should use numbers and punctuation marks . Aa Bb Cc Dd Ee Passwords should use uppercase and lowercase letters . You should use a different password for each account that you have. Passwords should not use words found in the dictionary . KS3 Home

  • OCR CTech IT | Unit 1 | 3.1 - Server Types | CSNewbs

    3.1 - Server Types Exam Board: OCR Specification: 2016 - Unit 1 What is a server? A server is a powerful dedicated system on a network. It requires increased memory, storage and processing power than traditional computer systems to fulfill its role across the network. Servers need to be scalable - this means they must be adaptable and able to efficiently manage the needs of connected systems . Servers have different roles so a company may use multiple server types within their organisation, each with a specific purpose. File Server A file server centrally stores and manages files so that other systems on the network can access them. ​ The server provides access security , ensuring that only users of the appropriate access level can access files. File servers can be used to automatically backup files , as per the organisation's disaster recovery policy. Using a file server frees up physical storage space within a business and can provide printing services too. Printer Server These servers control any printers on a network and manage printing requests by sending the document to an appropriate printer. ​ Print servers use spooling to queue print jobs so that they are printed when the printer is ready. If a fault occurs with a certain printer, work can be automatically diverted to another available printer. Application Server These servers allow users to access shared applications on a network. All users will be able to access common applications like email software or word processing but the server will also restrict certain applications to those with invalid access levels (such as hiding financial databases from employees outside of the finance department). Simplified updates can be deployed just to the application server instead of each machine that runs the application, saving a lot of time. ​ Installers can be found on an application server, allowing the software to be easily installed on other machines. Database Server These servers manage database software that users on the network can access and use to manipulate data . Data held on the server will be stored in a database accessible from multiple connected computers . The data can be modified using query languages such as SQL. ​ Storing data on a database server, rather than individual computers, is more reliable . A database server for a business also allows for scaling - for example, the database can be increased in size if the customer base grows. Web Server A web server manages HTTP requests from connected devices to display web pages on web browsers . A request (e.g. is sent to the web server. The server contains a list of known URLs and their matching IP addresses . The server contacts the server where the web page is held and delivers the web page to the client . Mail Server These servers send and receive emails using email protocols (SMTP & POP) allowing email communication between other mail servers on other networks. ​ The server makes sure emails are delivered to the correct user on the network. ​ Email servers can store company address books making internal communication easier for organisations. ​ The server may have anti-spam functions to reduce junk mail. Hypervisor A hypervisor allows a host machine to operate virtual machines as guest systems. The virtual machines share the resources of the host , including its memory, processing power and storage space. ​ This type of technology is called virtualisation . The guest machines are isolated so if one failed, the other guests and the hosts are not affected - demonstrating good security . ​ The hypervisor optimises the hardware of the host server to allow the virtual machines to run as efficiently as possible. Q uesto's Q uestions 3.1 - Server Types: 1a. What is a server ? Why does it need to be scalable ? [2 ] 1b. State the 7 types of server . [1 each ] ​ 2. A medium-sized animation company working on a movie are considering buying a server. Describe each type of server and the different roles they have. a. File Server b. Printer Server c. Application Server d. Database Server e. Web Server f. Mail Server g. Hypervisor [4 each ] 3. What type of technology does a hypervisor use to control multiple virtual machines? [1 ] 2.7 - Protocols Topic List 3.2 - Virtualisation

  • Python | Setting up Python | CSNewbs

    Setting up Python Downloading Python If you are using Python in Computer Science lessons, then your school should already have it downloaded and installed on the school computers. ​ It is a good idea to download it on a home computer too so you can practice outside of lessons. Python is free and can be downloaded from the official website. You should download the most up-to-date version of Python 3. ​ Save the file and then run it to start installing. Official Download Page Using Python When you run the Python application, it will open the shell. This window will display the outputs of any program you have created. ​ Do not type into the shell . ​ Click on the File tab then New File to open the editor. Python Shell - This displays the outputs of your program. Do not write directly into the shell . Python Editor - All code is written into the editor. When you want to test a program press the F5 key (or click the Run tab then Run Module ). The first time you test a program, it will prompt you to save the file. Make sure you save it somewhere you will remember - it is a good idea to create a folder named 'Python' where you can keep all your practice programs. The next page looks at actually creating a program but above shows how code has been typed into the editor and then displayed in the shell. ​ You never need to save the shell window. Also, the editor saves automatically every time you run the program. Opening a Saved Program When you want to re-open and edit a file you have created previously double-clicking on it won't work . ​ Right-click on the file and select Edit with IDLE : 1 a - Printing ➡

  • Key Stage 3 Python | The Basics | CSNewbs

    Python - #1 - The Basics 1. Start with Commenting Programmers write A LOT of code. They need to understand exactly what they have written, especially if they are working as part of a team or returning to code after working on other projects. ​ To help them understand what they have written, programmers use comments to annotate (explain) their code . Task 1 - Create a new Python program and use # to write a comment that says your name and the date. Save the file as In Python, type the # symbol then your message to write a comment. ​ Comments are not printed when you run a program! ​ It is a good idea to start every program with a comment, so you know what the program is about . 2. Printing to the Screen The most basic and common command you will use in Python is print . ​ Inside the print brackets, you can write a message within speech marks . ​ Your print command should turn purple - don't use any capital letters in Python unless it is inside speech marks! Task 2 - Write a nice message by using the print command, brackets and speech marks. ​ Press F5 to run your program. 3. More Printing You can write multiple print lines one after another to print on different lines. Task 3 - Add two more print lines to your program. You can choose any message that you like. 4. New Lines You can use the special command \n to start a new line . This allows you to write on multiple lines but only use one print line. ​ Use the backslash ( \ ) not the forward-slash ( / ). Task 4 - Use \n to write a 3 sentence conversation in only one line of code. Challenge Programs Use everything that you have learned on this page to help you create these programs... ​ Challenge Task 1 - Days of the Week Create a new Python program. Save it as ' ' Add a comment at the top with your name and the date. Create a program that prints the days of the week, with each day on a new line. ​ BONUS : Try to use only one print line. BONUS : Have no empty spaces at the start of each line. ​ When you run it, it should look like this: Challenge Task 2 - Conversation Create a new Python program. Save it as ' ' Add a comment at the top with your name and the date. Create a program that prints a 6-line conversation between two people. It is up to you what these two people are talking about. ​ BONUS : Try to use only one print line. BONUS : Have no empty spaces at the start of each line. ​ When you run it, it could look something like this: #2 Variables >>>

  • Python | 7a - Procedures | CSNewbs

    top Python 7a - Procedures Subroutines A subroutine is a section of code that can be re-used several times in the same program. It is separate from the main code and has to be ‘called’ upon. Subroutines are designed to be repeated, and they have three key benefits: ​ Subroutines make programs easier to read . They reduce the duplication of code . Complex problems are broken down into smaller chunks . ​ There are two types of subroutines: procedures and functions . ​ A procedure just executes commands , such as printing something a certain number of times. A function produces information by receiving data from the main program and returning a value to the main program. For example, a function could take the radius of a sphere from the main program, calculate a sphere’s area and return the value of the area to the main program. A function generally requires parameters to work – these are the values to be transferred from the main program to the subroutine. Procedures A procedure i s a type of subroutine that runs independently of the main program . ​ A subroutine must be defined at the top of the program before the main code by typing def and the name of the subroutine . ​ In the example below I have created a procedure to calculate the multiplication of two numbers and a separate procedure for the division. The main program starts beneath the subroutines , against the left side of the editor. ​ I have created a while true loop that asks the user if they want to multiply, divide or stop the program. ​ If they choose to multiply, the multiply subroutine is called . This initiates that subroutine then returns to the main program when it is complete. ​ If they choose to divide, the divide subroutine is called instead. Typing stop will break (end) the loop. Here you can see the two parts of the program put together. ​ Subroutines must be written first , with the rest of the program underneath. Subroutines can be called in any order . Below I have run the program and divided then multiplied before breaking the loop: Practice Tasks 1 1. Create a procedure called hello that just prints “Hello there! ”. ​ In the main program create a for loop that calls the procedure 10 times. ​ You must use a procedure. 2. Create a program with two procedures. The addition procedure allows the user to add two numbers together. The subtraction procedure allows the user to take a number away from another. Use a while true loop in the main program and a break to stop the loop. Example solution for #1: Local & Global Variables Programming languages use local variables and global variables . ​ A global variable can be used anywhere in the program . ​ A local variable can only be used in the subroutine it is created in . ​ I have adapted the multiply / divide program below to use global variables by stating the global command and the name of the variables in each subroutine. This allows me to ask the user to enter numbers in the main program. Practice Tasks 2 1. Adapt your addition / subtraction program from the first practice task section to use global variables. ​ 2. Create a program that asks the user to enter their name in the main program. Call a subroutine that greets the user using the name variables. You must use a procedure and a global variable . Example solution for #2: ⬅ Section 6 Practice Tasks 7b - Functions ➡

  • 3.2a - Databases & Normalisation | OCR A-Level | CSNewbs

    Exam Board: OCR 3.2a - Databases & Normalisation Specification: A-Level 2015 An instruction set is a list of all the instructions that a CPU can process as part of the FDE cycle . ​ CPUs can have different sets of instructions that they can perform based on their function. The two most common instruction sets are the simpler RISC (Reduced Instruction Set Computer ) and more complicated CISC (Complex Instruction Set Computer ). Instruction Sets This page is still being updated. Graphical Processing Unit What is cache memory? ​ Cache memory is temporary storage for frequently accessed data . ​ Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? ​ Cache memory is temporary storage for frequently accessed data . ​ Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? ​ Cache memory is temporary storage for frequently accessed data . ​ Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Q uesto's Q uestions 3.2a - Databases & Normalisation: ​ 1. What is cache memory ? [ 2 ] ​ 3.1b - Encryption & Hashing Theory Topics 3.2b - SQL

  • Python | 2a - Inputting Text | CSNewbs

    top Python 2a - Inputting Text Inputting Text (Strings) in Python A string is a collection of characters (letters, numbers and punctuation) such as: “Wednesday” , “Toy Story 4” or “Boeing 747” . ​ Use the input command to ask a question and let a user input data , which is automatically stored as a string . Variable to save the answer into. Give it a suitable name based on the input. name = input ( "What is your name? " ) = What is your name? Paulina Type your answer directly into the editor and press the Enter key. Statement that is printed to the screen. Leave a space to make the output look clearer. Once an input has been saved into a variable, it can be used for other purposes, such as printing it within a sentence : name = input ( "What is your name? " ) print ( "It is nice to meet you" , name) = What is your name? Jake the Dog It is nice to meet you Jake the Dog Always choose an appropriate variable name when using inputs. colour = input ( "What is your favourite colour? " ) print ( "Your favourite colour is " + colour + "? Mine is yellow." ) = What is your favourite colour? blue Your favourite colour is blue? Mine is yellow. Inputting Text Task 1 ( Holiday) Write an input line to ask the user where they last went on holiday . Write a print line that uses the holiday variable (their answer). Example solution: Where did you last go on holiday? Scotland I hope you had a nice time in Scotland Inputting Text Task 2 ( New Neighbour) Write an input line to ask the user for a title (e.g. Mr, Mrs, Dr). ​ Write another input line for an object . ​ Write a print line that uses both input variables (title and object ). Example solutions: Enter a title: Dr Enter an object: Fridge I think my new neighbour is Dr Fridge Enter a title: Mrs Enter an object: Armchair I think my new neighbour is Mrs Armchair Using a Variable Within an Input To use a variable you have previously assigned a value t o within the input statement you must use + (commas will not work). drink = input ( "What would you like to drink? " ) option = input ( "What would you like with your " + drink + "? " ) print ( "Getting your" , drink , "and" , option , "now...." ) = What would you like to drink? tea What would you like with your tea? biscuits Getting your tea and biscuits now... What would you like to drink? apple juice What would you like with your apple juice? cake Getting your apple juice and cake now... Inputting Text Task 3 ( Name & Game) Ask the user what their name is. ​ Ask the user what their favourite game is. Use their name in the input statement for their game. ​ Print a response with their name and the game they entered. Example solutions: What is your name? Rory Hi Rory, what's your favourite game? Minecraft Rory likes Minecraft? That's nice to know. What is your name? Kayleigh Hi Kayleigh, what's your favourite game? Stardew Valley Kayleigh likes Stardew Valley? That's nice to know. ⬅ Section 1 Practice Ta sks 2b - I nputting Numbers ➡

  • Python | 7b - Functions | CSNewbs

    top Python 7b - Functions What is a Function? A function is a subroutine that takes one or more values from the main program and returns a value back. For example, transferring over a sphere’s radius from the main program for the function to calculate a surface area and then return that value to the main program. The two key differences between procedures and functions are: A function uses parameters to transfer data from the main program into the function. A function returns a value to the main program. Writing Functions A function is written the same way as a procedure but it uses parameters . In the example below the parameters are num1 and num2 which are sent from the main program to be used in the function . The return command is used to send a value back to the main program . Below is another example of a function that takes the radius of a sphere and works out the area in a separate function . ​ The area is returned to the main program and printed. Subroutines can be reused and called with different parameters . ​ The program below repeatedly takes an integer input and adds it to a total in a function that is then returned and printed. Practice Task Create a program similar to the sphere example above, this time to work out the volume of a cylinder. ​ In the main program ask the user to enter the cylinder's radius and then its height. ​ The actual calculation should be done in a function and returned to the main program. ​ The calculation for a cylinder's volume is: ​ pi x (radius x radius) x height ​ Extension: Use the round command from section 9b to round the number to 2 decimal places. Example solution: Using Subroutines as a Menu Subroutines are often used to split programs up and give users a selection of options . ​ Subroutines are used for this purpose because they are separate , making it easier to code and manage a program . ​ The example below for a simplified online banking system uses separate subroutines accessible within a while true loop . ​ Depending on the option chosen by the user, the appropriate subroutine will be called . Instead of a further practice task here, Task 4 of the Section 7 Practice tasks page challenges you to make a similar program using multiple subroutines. ⬅ 7a - Proced ures Section 7 Practice Tasks ➡

  • 1.1a- The CPU & FDE Cycle | OCR A-Level | CSNewbs

    Exam Board: OCR 1.1a: The CPU & The FDE Cycle Specification: A-Level 2015 The Central Processing Unit ( CPU ) is the most important component in any computer system. ​ The purpose of the CPU is to process data and instructions by constantly repeating the fetch - decode - execute cycle . CPU Components The control unit directs the flow of data and information into the CPU. It also controls the other parts of the CPU . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . The registers are temporary storage spaces for data and instructions inside the CPU . ​ The registers are used during the FDE cycle . ​ Five essential registers are explained below. Important Registers A register is a small storage space for temporary data in the CPU . Each register has a specific role . There are five essential registers used in the FDE cycle : ​ Program Counter (PC) A register that tracks the RAM address of the next instruction to be fetched . Memory Address Register (MAR) A register that tracks the RAM address of data that is currently being accessed . Memory Data Register (MDR) ​ The MDR stores the data that is transferred from RAM to the CPU . Current Instruction Register (CIR) A register that stores the instruction that has been fetched from RAM , and is about to be decoded or executed . Accumulator (ACC) ​ The ACC stores the result of executions performed in the FDE cycle . The FDE Cycle The essential idea of the FDE cycle is that instructions are fetched from RAM , to be decoded (understood) and executed (processed) by the CPU . ​ The Fetch - Decode - Execute (FDE) cycle is performed by the CPU millions of times every second. ​ This cycle is how the CPU processes data and instructions for each program or service that requires its attention. 1. 2. 3. The Program Counter (PC ) register displays the address in RAM of the next instruction to be processed . This value is copied into the Memory Address Register (MAR ). 0054 The PC register is increased by 1 . ​ This prepares the CPU for the next instruction to be fetched. 0055 The CPU checks the address in RAM which matches the address held in the MAR . 0054 4. The instruction in RAM is transferred to the Memory Data Register (MDR ). MDR 5. The instruction in the MDR is copied into the Current Instruction Register (CIR ). MDR CIR 6. The instruction in the CIR is decoded (understood) and executed (processed). Any result of an execution is stored in the Accumulator (ACC ) register. CIR ACC 7. The cycle repeats by returning to the first step and checking the program counter for the address of the next instruction . Buses Data is transferred within a computer system along pathways called buses . ​ There are three types of bus: Address Bus Sends a memory address of where data is stored.​​ The address is sent from the CPU to RAM in the FDE cycle. Data Bus Transfers data between components. Data is sent both ways . Control Bus Sends control signals from the control unit to other components of the system. Status signals are sent back to the CPU. Think about which buses would be used during the FDE cycle and when. ​ For example, look back at stages 3 and 4 of the FDE cycle above. The address bus is used to send the address in RAM of the next instruction . The control bus is used to send the fetch signal . The data bus is used to transfer the instruction from RAM to the MDR . Computer Architecture The way a computer is designed and internally organised is known as its architecture . ​ The most common type of computer architecture is Von Neumann architecture . Von Neumann Architecture The key features of Von Neumann architecture include: The CPU , which constantly performs the FDE cycle , and contains: One control unit One ALU Special registers ​ D ata and instructions are stored in the same format in the same area in memory . Instructions are commands and data are the specific values used when processing. ​ Data and instructions are transferred across buses (pathways) between the CPU, memory and input or output devices. Harvard Architecture The key features of Harvard architecture include: ​ The CPU , which constantly performs the FDE cycle , and contains: One control unit One ALU ​ D ata and instructions are stored in separate areas in memory . Instructions are commands and data are the specific values used when processing. ​ Data and instructions are transferred across buses (pathways) between the CPU, data memory, instruction memory and input or output devices. Q uesto's Q uestions 1.1a - The Central Processing Unit (CPU): ​ 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] ​ 2a. Draw a diagram of the CPU , use the same symbols as shown on this page. [ 4 ] 2b. Label the three main components of the CPU. [ 4 ] ​ 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] ​ 4a. Describe the key features of Von Neumann architecture . [ 3 ] 4b. Describe the differences between the two main types of architecture. [ 2 ] Theory Topics 1.1b - Performance

  • 1.4 - Internet Connections | Unit 2 | OCR Cambridge Technicals | CSNewbs

    1.4 - Internet Connections Exam Board: OCR Specification: 2016 - Unit 2 The internet i s a global network of interconnected networks . ​ There are multiple methods of connecting to the internet . Wired Connections Copper Cables Copper cables are a cheaper type of wired internet connection that may be poorly insulated and therefore susceptible to electromagnetic interference . ​ Copper cables are more likely to suffer from attenuation (network distortion ). ​ However, they are malleable (easier to bend) and less likely to break than other cables such as fibre optic. They have a lower bandwidth - cannot transmit as much data at once - than fibre optic cables. Fibre Optic Cables Fibre optic cables are a very fast but expensive type of wired internet connection. Signals are transmitted as waves of light through a glass tube. Because of this fibre optic cables are not affected by electromagnetic interference and suffer less from attenuation . ​ Fibre optic cables have a higher bandwidth - can transfer more data at one time - than copper cables but they are more fragile . Wireless Connections Bluetooth Bluetooth is a temporary short-range communication between devices within a limit of about 10 metres . For example, Bluetooth can be used to transfer audio files from one smartphone to another. ​ The close proximity is a disadvantage but no other hardware is required for a connection. Microwave Microwave connections use radio waves to send signals across a large area via microwave towers . It can transmit a large amount of data but antennas must be in the line of sight of each other with no obstructions . ​ Microwave connections are affected by bad weather , leading to higher chances of attenuation (network distortion ). Satellite Satellite networks use point-to-multipoint communication by using satellites above the Earth's atmosphere that receive a transmission and rebroadcast them back to Earth. Because of the distance between the communication device and the satellite (roughly 45,000 miles), there is a delay between data transmission and it being received. GSM / 5G GSM (Global System for Mobile communications ) is a technology for allowing mobile phones to connect to a network for calls and text messages. ​ Advances in mobile technology are classified by generations such as 4G and 5G (the current generation). Each generation is generally faster, more secure and allows for new opportunities. Connection Characteristics When connecting to the internet there are several characteristics that a user must consider:​ Strength Range Latency Bandwidth Storage Capacity Contention Latency is the delay when sending data across a network. Bandwidth is the maximum amount of data that can be sent across a network at once . Contention refers to whether a network is dedicated ( uncontended ) or shared between users ( contended ). Q uesto's Q uestions 1.4 - The Internet: ​ 1. Compare the differences between copper and fibre optic cables (possibly in a table) by the following features: a. Price b. Bandwidth c. Interference d. Attenuation e. Malleability / Fragility [2 each ] ​ 2. Describe each of the different types of wireless connection . Try to list 1 advantage and 1 disadvantage of using each type. a. Bluetooth b. Microwave c. Satellite d. GSM / 5G [5 each ] ​ 3a. State the 6 characteristics of a network. [6 ] 3b. Describe what is meant by the following characteristics : i. Latency ii. Bandwidth iii. Contention [1 each ] 1.3 - Access & Storage Devices Topic List 1.5 - WWW Technologies

  • 3.9 - Protection Against Threats - GCSE (2020 Spec) | CSNewbs

    3.9: Protection Against Threats Exam Board: Eduqas / WJEC Specification: 2020 + Network Forensics & Penetration Testing What is network forensics? Network forensics is the monitoring of a network to identify unauthorised intrusions . Network forensics is used to record and analyse attacks on a network and to gather other information about how the network is performing. ​ It is important for organisations to identify weaknesses in their networks so that they can fix them and be prepared for any type of attack or malware. ​ Footprinting - Footprinting is one method of evaluating a network’s security . This is when a security team puts itself in the attacker’s shoes by obtaining all publicly available information about the organisation and its network . Footprinting allows the company to discover how much detail a potential attacker could find out about a system. The company can then limit the technical information about its systems that is publicly available . Penetration Tests Penetration tests are carried out as part of ethical hacking. Ethical hacking is when an organisation gives permission to specific 'good ' hackers to try and attack a system so that the weak points can be highlighted and then fixed. The purpose of a penetration test is to review the system's security to find any risks or weaknesses and to fix them . ​ There are four main types of penetration tests : Internal tests are to see how much damage could be done by somebody within the company with a registered account. External tests are for white hat hackers to try and infiltrate a system from outside the company . Blind tests are done with no inside information , to simulate what a real attacker would have to do to infiltrate the system. + Targeted tests are conducted by the company's IT department and the penetration team cooperating together to find faults in the system. Anti-Malware & Firewalls Anti-Malware Software Anti-malware software is used to locate and delete malware, like viruses, on a computer system. The software scans each file on the computer and compares it against a database of known malware . Files with similar features to malware in the database are identified and deleted . There are thousands of known malware, but new forms are created each day by attackers, so anti-malware software must be regularly updated to keep systems secure. Other roles of anti-malware software: Checking all incoming and outgoing emails and their attachments . Checking files as they are downloaded . Scanning the hard drive for viruses and deleting them . Firewall A firewall manages incoming and outgoing network traffic . Each data packet is processed to check whether it should be given access to the network by examining the source and destination address . ​ Unexpected data packets will be filtered out and not accepted to the network. Other roles of a firewall include: Blocking access to insecure / malicious web sites . Blocking certain programs from accessing the internet . Blocking unexpected / unauthorised downloads . Preventing specific users on a network accessing certain files . Other Methods of Protection Double Authentication Also known as two-factor authentication (2FA ), this is a method of confirming someone's identity by requiring two forms of authorisation , such as a password and a pin code sent to a mobile. 4392 Secure Passwords Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system. ​ Passwords should contain a mix of uppercase and lowercase letters , punctuation and numbers . Passwords should be of a substantial length (at least 8 characters) and should be regularly changed . ******** User Access Levels Access levels are used to only allow certain users to access and edit particular files. ' Read-Only ' access is when a user can only view a file and is not allowed to change any data . ​ For example, a teacher might set homework instructions as read-only for students to view. ' Read and Write ' access allows a user to read and edit the data in a file. ​ For example, a teacher might set an online workbook as read and write access for students to fill in. It is important to set access levels so that only authorised users can view and change data. The more users who have access to a file, the more likely it is to be compromised. Certain users may also have no access to a file - when they can't view or edit it. Encryption Encryption is the process of scrambling data into an unreadable format so that attackers cannot understand it if intercepted during transmission. ​ The original data (known as plaintext ) is converted to scrambled ciphertext using an encryption key . Only at the correct destination will the encryption key be used to convert the ciphertext back into plaintext to be understood by the receiving computer. ​ A very simple method of encryption is to use the XOR logical operator . XOR is used on the plaintext and key together to create the ciphertext . Using XOR again on the ciphertext and key will reverse the encryption to reveal the plaintext . Encryption using XOR Plaintext = 00110100 Key = 10100110 XOR Ciphertext = 10010010 Decryption using XOR ​ Ciphertext = 10010010 / Key = 10100110 XOR Plaintext = 00110100 Q uesto's Q uestions 3.9 - Protection Against Threats: ​ 1a. What is network forensics ? Why is it important ? [ 3 ] 1b. Explain what is meant by footprinting and why companies do it . [ 2 ] 2. What is an ethical hacker ? [2 ] 3a. Describe the purpose of penetration tests . [2 ] 3b. Describe each type of penetration test . [ 8 ] ​ 4. Describe the purpose of anti-malware software and its different roles . [ 4 ] 5. Describe the purpose of a firewall and its different roles . [ 4 ] ​ 6a. Describe double authentication . [2 ] 6b. State three rules for choosing a strong password . [ 3 ] 7. Describe the three types of access level . [6 ] 8a. Describe the purpose of encryption . [ 2 ] 8b. Explain how encryption works, using the terms plaintext , key and ciphertext . [ 4 ] 3.8 - Cyber Threats Theory Topics 4.1 - Number Systems

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