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4.1: Security Threats Exam Board: OCR Specification: 2020 Types of Malware ​Malware is any type of harmful program that seeks to damage or gain unauthorised access to your computer system. Virus A virus can replicate itself and spread from system to system by attaching itself to infected files . A virus is only activated when opened by a human . Once activated, a virus can change data or corrupt a system so that it stops working . Worm A worm can replicate itself and spread from system to system by finding weaknesses in software . A worm does not need an infected file or human interaction to spread. A worm can spread very quickly across a network once it has infiltrated it. Trojan A trojan is a harmful program that looks like legitimate software so users are tricked into installing it . A trojan secretly gives the attacker backdoor access to the system . Trojans do not self replicate or infect other files. Spyware Spyware secretly records the activities of a user on a computer. The main aim of spyware is to record usernames, passwords and credit card information . All recorded information is secretly passed back to the attacker to use. Keylogger A keylogger secretly records the key presses of a user on a computer. Data is stored or sent back to the attacker. The main aim of a keylogger is to record usernames, passwords and credit card information . Keyloggers can be downloaded or plugged into the USB port . Ransomware Ransomware locks files on a computer system using encryption so that a user can no longer access them. The attacker demands money from the victim to decrypt (unlock) the data . ? ? ? ? Attackers usually use digital currencies like bitcoin which makes it hard to trace them. SQL Injection SQL ( Structured Query Language ) is a programming language used for manipulating data in databases . ​ A SQL injection is when a malicious SQL query (command) is entered into a data input box on a website. ​ If the website is insecure then the SQL query can trick the website into giving unauthorised access to the website’s database . ​ An SQL injection can be used to view and edit the contents of a database or even gain administrator privileges . ' or 1 = 1 DoS Attack A DoS (Denial of Service ) attack is when a computer repeatedly sends requests to a server to overload the system . A server overload will slow the system and may take websites offline temporarily. ​ A DDoS (Distributed Denial of Service ) attack is a coordinated attack using a botnet of infected systems to overload a server with requests . A botnet is a large group of devices controlled and used maliciously by an attacker. Brute-Force Attack Every possible combination is tested in order from start to finish . This is not a quick method but it should break the password eventually and can be sped up if multiple computer systems are used at the same time. Social Engineering Social engineering means to trick others into revealing their personal data by posing as a trusted source . For example, impersonating an IT technician of a school via email and asking for a student's username and password . Interception This is when data packets on a network are intercepted by a third party (e.g. a hacker) and copied to a different location than the intended destination. ​ Software called packet sniffers are used to intercept and analyse data packets. 4.1 - Security Threats: 1. What is malware ? [ 2 ] 2a. Describe three characteristics of a virus . [3 ] 2b. Describe three characteristics of a worm . [3 ] 2c. What is a trojan ? [ 3 ] 2d. Describe how spyware and keyloggers work. [ 4 ] 2e. Explain how ransomware works and why it is difficult to trace attackers . [ 3 ] 2f. In your opinion, which malware do you think is the most dangerous and why ? [ 2 ] 3. Describe what an SQL injection is and how an attacker would use it. [ 3 ] ​ 4a. Describe what a DoS attack is and its impact . [2 ] 4b. Describe how a DDoS attack is different to a DoS attack . [2 ] ​ 5a. Describe a brute-force attack. [ 2 ] 5b. Describe social engineering and give an example of when it might be used . [2 ] 5c. Describe interception . [2 ] Q uesto's Q uestions 3.2b - Protocols & Layers Theory Topics 4.2 - Preventing Vulnerabilities

Extended Task 1 Pete Porker's Pork Pie Emporium Hello, Pete Porker here... ​ I need a new program for customer orders at my bakery . ​ I need the customer to enter how many scotch eggs (49p each ), pork pies (85p each ) and quiche tarts (£1.45 ) they want to order. ​ Next, ask them to confirm their choice . If they are not happy , ask the questions again . ​ If they confirm their choice, print a receipt showing their order and total . ​ To make your program better, you should use validation (either while loops or error handling ) to make sure that a user must enter a correct value. Bronze Award --- Welcome to Pete Porker's Pork Pie Emporium --- ​ Scotch eggs are 45p, pork pies are 85p and quiche tarts are £1.49. ​ Enter the number of scotch eggs to buy: 9 Enter the number of pork pies to buy: 7 Enter the number of quiche tarts to buy: 4 ----- You selected 9 scotch eggs, 7 pork pies and 4 quiche tarts. 9 scotch eggs = £4.05 7 pork pies = £5.95 4 quiche tarts = £5.96 ------- Total: £15.96 There are many ways to create this program, but below are some suggestions : ​ ​ Use inputs with int to let the user enter how many of each item they want. ​ Use total variables , e.g. totaleggs = eggs * 0.45 to work out the total cost for eggs, pies and tarts. ​ Set a finalcost variable by adding the total of the three items together. ​ Use dashes and \n (which makes a new line ) inside speech marks to make your program more presentable . Silver Award --- Welcome to Pete Porker's Pork Pie Emporium --- ​ Scotch eggs are 45p, pork pies are 85p and quiche tarts are £1.49. ​ Enter the number of scotch eggs to buy: 5 Enter the number of pork pies to buy: 3 Enter the number of quiche tarts to buy: 6 ----- You selected 9 scotch eggs, 7 pork pies and 4 quiche tarts. ----- Are you happy with this selection? no Okay, enter your choices again. ​ Enter the number of scotch eggs to buy: 6 Enter the number of pork pies to buy: 2 Enter the number of quiche tarts to buy: 7 ----- You selected 6 scotch eggs, 2 pork pies and 7 quiche tarts. ----- Are you happy with this selection? yes Excellent! Here is your receipt : ​ 6 scotch eggs = £2.70 2 pork pies = £1.70 7 quiche tarts = £10.43 ------- Total: £14.83 There are many ways to improve this program and below are some suggestions : ​ ​ Use a while loop to repeat the input stage until the user is happy with their choices. ​ You will need to ask the user if they are happy with the values that were entered and then use an if statement to repeat the loop if they enter 'no '. Gold Award Example solution: --- Welcome to Pete Porker's Pork Pie Emporium --- ​ Scotch eggs are 45p, pork pies are 85p and quiche tarts are £1.49. ​ Enter the number of scotch eggs to buy: 9 Enter the number of pork pies to buy: 35 Sorry you must enter a number between 1 and 20. Starting again... Enter the number of scotch eggs to buy: 9 Enter the number of pork pies to buy: 20 Enter the number of quiche tarts to buy: 7 ----- You selected 9 scotch eggs, 20 pork pies and 7 quiche tarts. ----- Are you happy with this selection? YES ​ Excellent! Here is your reciept: ​ 9 scotch eggs = £4.05 20 pork pies = £17.00 7 quiche tarts = £10.43 ------- Total: £31.48 There are many ways to make this program even better and below are some suggestions : ​ ​ Include validation so that the user can only enter numbers between 1 and 20 . You will need to use if statements and the and operator to do this. ​ You can include additional features to your program such as rounding the number to two decimal places and including coloured text using the Colorama library (which will only work if you are using an online editor like Replit ). ​ You can use the .lower() command when checking if the user is happy with their choices to automatically accept 'Yes' and 'YES '. ​ If you really want to challenge yourself you could consider outputting the receipt in order from most expensive to least expensive , using if statements to check the three values (although that has not been done in this example on the left). Helpful reminders for this task: Inputting Integers While Loops Calculations Rounding Integers ⬅ 12 - Error Handling Extende d Task 2 (Lottery) ➡

Key Stage 3 Topics Hardware Python Basics 1. Motherboard 2. The CPU 3. Memory 4. Expansion Cards 1. The Basics 2. Variables 3. Inputs 4. Calculations 5. Selection 6. Turtle 7. Link to GCSE Python Cyber Security 1. Malware 2. Phishing & Staying Safe Desktop Publishing (DTP) Desktop Publishing

6.5 - Physical Protection Exam Board: OCR Specification: 2016 - Unit 2 RFID & Tokens Radio-frequency identification (RFID) uses electromagnetic fields to attach tags to physical objects . RFID tags can be embedded within 'dumb' objects such as clothing, packages and even animals. RFID is used with security tokens (such as an ID keycard ) to permit the access of authorised people to certain areas. ​ RFID can be used by IT companies to track equipment and manage access . Shredding This is the cutting up of documents (paper or CDs ) into small pieces so that they cannot be reassembled and read. Sensitive data on paper or optical disc should be shredded when no longer required. Locks A lock can be used to prevent access to server rooms or sensitive data stores . Only authorised personnel with the right key will have access. Physical Security Measures Backup Backups should be taken regularly and stored at a secure location away from the main site. Backups could also be stored on cloud servers so that any damage to the organisation's building will not affect the backup as well. Biometrics Biometric devices require the input of a human characteristic (such a fingerprint , iris or voice scan ). The biometric data is checked against previously inputted data in a database . A match will allow access to the user. Security Staff Staff may be employed to physically prevent unauthorised people from accessing certain areas of a building where sensitive information is stored. They may check ID keycards or use surveillance like CCTV to monitor who is entering and exiting a secure area. Q uesto's Q uestions 6.5 - Physical Protection: ​ 1. Explain how locks can be used as a physical security method within an organisation. [2 ] ​ 2. Explain what RFID is and how it can be used with tokens as a physical security method. [3 ] ​ 3. Explain how biometric devices can be used as a physical security method. [3 ] ​ 4. Explain how security staff can be employed to protect data. [2 ] ​ 5. What is the purpose of shredding ? [2 ] ​ 6. Why should backups be stored off-site ? [1 ] 6.4 - Protection Measures Topic List 6.6 - Logical Protection

Exam Board: OCR 4.1d - Binary Calculations 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 4.1d - Binary Calculations: ​ 1. What is cache memory ? [ 2 ] ​ 4.1c - Signed Binary & Floating Point Theory Topics 4.1e - Shifts & Masks

5.6 - Data & System Disposal Exam Board: OCR Specification: 2016 - Unit 1 Computer components such as circuit boards, processors and monitors contain hazardous materials that cannot be disposed of in traditional ways such as rubbish collection and landfills. For security reasons, data must also be disposed of carefully so that it is not returned to a readable format by unauthorised viewers . Legislation In recent years the government has introduced different laws that relate to the safe disposal of computer equipment to help reduce environmental impact . ​ Waste Electronic and Electrical Equipment ( WEEE ) Directive: ​ Gives guidance on how hazardous materials should be disposed of safely . This includes material such as mercury (found in smartphones and newer monitors) and toner cartridges in printers. These materials can damage the environment if not disposed of appropriately. ​ Waste Acceptance Criteria ( WAC ) : ​ Before equipment can be sent to a landfill it has to pass this set of rules . Hazardous material like the elements found in computer monitors will not pass these criteria and should therefore not be accepted to landfills. ​ Hazardous Waste Directive: Ensure that businesses store hazardous materials and equipment safely and use authorised businesses to dispose of the waste . Hazardous materials include mercury and hexavalent chromium. ​ Data Protection Act ( DPA ) : ​ One principle of the DPA specifies that data should only be kept for a reasonable amount of time until it is securely deleted . Methods of Data & System Disposal Overwriting is when data is sent to the hard disk drive to overwrite the binary values currently on the drive - resetting the data . Overwriting just once is usually not enough to remove all evidence of the data and the process should be repeated several times . Overwriting data means the drive can still be used for other purposes afterwards. Electromagnetic wiping uses a machine called a degausser , which has a very strong electromagnetic coil , to completely wipe the hard disk drive . ​ Many large organisations use degaussers to be sure that their data is no longer on the devices they have used so it can’t be restored and accessed by unauthorised viewers . ​ Degaussers are expensive to buy but it allows the device to be used again for other purposes afterwards as it is not physically damaged. A third option is the physical destruction of a system or hard disk drive which will guarantee that the data is permanently inaccessible . However physical destruction also renders the storage media unusable again for other purposes. ​ Examples of physical destruction include shredding or tools such as sledgehammers if no other option is available. Q uesto's Q uestions 5.6 - Data & System Disposal: ​ 1. Describe the purpose of 4 different pieces of legislation relating to how data or computer systems should be disposed of safely . [8 ] ​ 2a. State 3 methods of data and system disposal . [3 ] 2b. Describe 1 advantage and 1 disadvantage of using each method you stated in 2a. [6 ] 5.5 - Digital Security Topic List

1.1 - Holders of Information Exam Board: OCR Specification: 2016 - Unit 2 Categories of Information Holders Organisations that store and process information can be put into seven different categories : Business A business will hold information on all of its employees , including their date of birth, address and financial information , allowing them to be paid at the end of each month. Businesses will also hold commercial information about their organisation such as profits and losses, product descriptions and historical data . Many companies may record information about their competitors and general marketing data. Government The government will hold a huge amount of information about all citizens in the country including financial earnings, tax paid, births and deaths . The electoral roll holds information about addresses . A national census is taken every 10 years in the UK (the next census is in 2021) that records extensive data about everyone living in the country. The government also stores information about other countries and shares some of this publicly, such as the Foreign Office posting travel advice . Individual Education Educational organisations , such as schools, colleges and universities will hold information about current and past students as well as staff. Student information such as addresses, attendance records and examination history will be recorded, as well as contact information for parents and guardians. Teacher information will be stored too, as well as students that previously attended the institution, even for a number of years after they have left. An individual will hold information about themselves , either in their head or on paper or electronically. This includes their name, date of birth, address, usernames and passwords . Individuals will store information of others , such as phone numbers, social media details and email addresses . Other information will be about organisations , such as the address of their favourite restaurant, opening hours of the local cinema or the telephone number from a catchy advert. Healthcare Healthcare services , like the NHS in the United Kingdom, will hold entire medical histories for each civilian in the country. This includes basic personal information such as current address and date of birth but much more detailed data too like previous illnesses and operations, blood type, allergies and prescriptions . The data stored by healthcare organisations is usually confidential and should not be shared by anyone other than the citizen in question. Charity & Community Charities may hold financial information of donors who give money to them, as well as information about the different projects that the donations are funding. Charities such as the British Heart Foundation might have physical addresses on the high street so information may be kept about the shops too. Community organisations like sport centres or religious institutions may hold information on members and matches, meetings or events . Comparison of Locations The location of systems and data affects access speed and network quality . ​ The digital divide is the gap between people who do and do not have easy access to computers and networks . Developed vs. Developing Countries Developed countries , like areas of Western Europe, North America and East Asia, have a more developed technology and industry base with more funding available for information infrastructures such as cabling and high-speed access . ​ Developing countries , like areas of Africa and Central Asia, have unstable governments and slower access (if any) to the internet . Less money is spent on technology and improving broadband speed and expensive equipment like computers cannot be purchased on low wages . Urban vs. Rural Urban locations like towns and cities have a high population density . Because there are so many people, councils and IT companies will spend a lot of money on internet infrastructure such as cabling and installing high-speed lines . ​ In Rural locations like the countryside, the population is sparse and settlements may be far apart so internet access is poorer and broadband speeds are slower . This means accessing information on the internet is more difficult . Internet Access from Remote Locations Remote locations (such as the countryside or difficult-to-reach areas like mountains or deserts) might have limited internet access . Fast fixed broadband is expensive to install and many providers simply won't invest in rural areas as it is not economically viable . Some areas, usually those with a very small or temporary population, might have no fixed internet access which will make it difficult for an individual or organisation to communicate or work online. Many remote locations have some form of internet but download speeds will be slow or interrupted due to intermittent connection . This makes it difficult to work online and could take a long time to access webpages or document stores. ​ Alternatives to fixed broadband in remote locations include mobile broadband and satellite broadband . Mobile broadband is generally not designed for home use and would be very expensive for everyday use , plus the remote location will generally mean mobile coverage could also be weak . Satellite broadband requires a dish with an unrestricted view of the sky. Satellite broadband has a relatively high internet speed but will cost a lot to install and has a high latency (more chance of experiencing lag). Q uesto's Q uestions 1.1 - Holders of Information: ​ 1a. State the 7 categories of information holders . [7 ] 1b. For each of the 7 categories , briefly describe 3 different pieces of information that may be stored by the information holder. For example, a charity may store the financial information of donors. [3 each ] ​ 2. What is the digital divide ? [2 ] ​ 3. Describe the differences in information access for the following locations : a. Developed vs. developing countries b. Urban vs. rural areas c. Remote locations [4 each ] Topic List 1.2 - Storage Media

Python - #5 - Selection 1. Using if Statements Using if enables your program to make a choice . ​ There are a few things you need to remember : if is lowercase - it should turn orange. You must use double equals == You need a colon : at the end of your if line. The line below your if line must be indented . ​ Task 1 - Create a new Python program and save the file as 5-Selection.py ​ Use the picture to help you ask what your favourite food is . Run the program and test it works. To indent a line press the tab key on your keyboard. ​ Indentation is important as it tells Python what is within the if statement and what isn't. 2. Using elif elif stands for 'else if '. It is used to respond in a different way depending on the input. ​ elif works exactly the same as an if line so if you make a mistake look up at task 1 to help you. Task 2 - Write an elif line that responds differently to your favourite food question from task 1. e.g. "Yum!" if someone enters "pasta". 3. Using else It is impractical to have hundreds of elif lines to respond to different inputs. ​ else is used to respond to anything else that has been entered in a general way. ​ The else line works a bit differently, so look carefully at the picture . Task 3 - Write an else line that responds to anything else the user enters for your favourite food question. 4. Multiple elifs Despite what you did in task 3, programs can be expanded with more than one elif line. ​ Underneath your first elif line but before your else line, add at least two more elif sections that respond differently depending on what is entered. ​ Use the elif line from the task 2 picture to help you. Task 4 - Read the description above and use task 2 to help you. Challenge Programs Use everything that you have learned on this page to help you create these programs... ​ Challenge Task 1 - Spanish Translation Create a new Python program. Save it as ' 5-Translator.py ' Add a comment at the top with your name and the date. Create a program that asks for a number between 1 and 4. Use if and elif statements to see what the user has entered and print a statement that displays the chosen number in Spanish - use the image to help you understand. ​ BONUS : Add an else line for any numbers higher than 4. ​ ​ When you run it, it could look something like this: Challenge Task 2 - Able to Vote Create a new Python program. Save it as ' 5-Vote.py ' Add a comment at the top with your name and the date. Create a program that asks for their age. Use an if statement to see if the age is more than 17 (use > instead of ==). If the age is over 17, then print "You are old enough to vote!" Use an else statement to print a different message for everyone else. ​ ​ When you run it, it could look something like this: Challenge Task 3 - Totals Create a new Python program. Save it as ' 5-Totals.py ' Add a comment at the top with your name and the date. Use an int input line to ask the user for number 1. Use an int input line to a sk the user for number 2. Multiply the two numbers together and save it into a variable called total. If the total is over 9000, then print "It's over 9,000!!!" Use an else statement to print the total if it is less than 9000. ​ ​ When you run it, it could look something like this: <<< #4 Calculations #6 Turtle >>>

2. Creating Essential Tags HTML Guide Watch on YouTube: What is a tag ? HTML uses tags to define the content of a webpage . ​ A tag uses angle brackets - they look just like my teeth... ​ Some examples of tags are and and ​ ​ ​ Most tags have a start tag and an end tag . The actual content is written in between the tags . For example : ​ The p tag is used to write a paragraph ​ Notice that the end tag uses a forward slash . < > Essential Tags There are three tags that are essential for every HTML web page : ​ - This tag declares the start and the end of your html web page. - The head is the part of the web page that the user will not see. - The body holds all of the content of the web page (text, images, video etc.) ​ Don't forget to use backslash for the end tags : / Use the image on the right to add the three essential tags (and their end tags) to your document. Now it is time to add something we can actually see! Text tags are up next. 1. Setup HTML Guide 3. Text Tags

Exam Board: OCR 2.4c: Object-Oriented Language 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 2.4c - Object-Oriented Language: ​ 1. What is cache memory ? [ 2 ] ​ 2.4b - Assembly Language Theory Topics 3.1a - Compression

Exam Board: OCR 3.1c - Data Structures: Stacks, Queues & Lists 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 3.1c - Data Structures: Stacks, Queues & Lists: ​ 1. What is cache memory ? [ 2 ] ​ 3.1b - Big O Notation Theory Topics 3.1d - Trees & Graphs

top Python 3a - Data Types Data Types in Python If you are a Computer Science student you need to know about the different data types that are used in programming. ​ ​String – A sequence of alphanumeric characters (e.g. “Hello!” or “Toy Story 4” or “Boeing 747” ) Integer – A whole number (e.g. 1470 or 0 or -34) Float (also called Real ) – A decimal number (e.g. -32.12 or 3.14) Boolean – A logical operation (True or False) Character – A single alphanumeric character (e.g. “a” or “6” or “?”) [ Not used in Python as it would just be a string with a length of 1] Converting to Another Data Type Converting a variable from one data type to another is called casting . Casting Commands ​ str (variable_name) converts a variable to a string . ​ int (variable_name) converts a variable to a integer . ​ float (variable_name) converts a variable to a float (decimal number). An integer (or float ) value may be cast into a string so that it can be used with + as part of a sentence to avoid spaces . total = 45 print ( "You owe £" , total , "in total." ) print ( "You owe £" + str (total) , "in total." ) = You owe £ 45 in total. You owe £45 in total. When dividing an integer the answer is automatically given as a decimal number (float ), even if it is .0 (e.g. 10 / 2 would give 5.0). ​ Casting a float (also known as real) number into an integer using int() will remove the decimal . total = 100/10 print ( "The answer is" , total ) print ( "The answer is" , int(total) ) The answer is 10.0 The answer is 10 = Data Types Task 1 ( Time) Write an input line with int to ask the current hour . Write another input line with int to ask the current minute . ​ Write a print line with str() that outputs this as a clock time. Example solution: What is the hour? 12 What is the minute? 44 The time is 12:44 Data Types Task 2 ( Decimal ) Write an input line with int to ask for any number . ​ Use float() in a print line to output number as a decimal. Example solution: Enter any number: 456 456.0 ⬅ Section 2 Practice Tasks 3b - Simple Calculations ➡