Cambridge A Level Information Technology (from 2017) 9626 — 2024 Feb/March Paper 3 · Variant 2

1 Near Field Communication (NFC) is a communication method. Describe how NFC can be used by mobile devices. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: Question Answer Marks 1 Six from e.g.: 6 • Used to bootstrap other wireless connections/Wi-Fi/Bluetooth (by exchanging setup credentials) • Used in games to customise objects/figures/characters (with e.g. personal data/enter online games) • Used in tags to automatically program/amend settings/command smartphones to carry out tasks/access a website • Used as identity tags/documentation in e.g. passports/ID cards • Used in access/login cards/car key systems • Used in social networking to share contacts/images/messages • Used in contactless payment systems in mobile devices/smartphones.

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2 Explain why break statements, functions and comments are used in JavaScript code. (a) Break statements ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) Functions ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (c) Comments ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2]

Mark scheme: 2(a) Two from: 2 • Used to exit/break out of a switch/loop • When exiting a loop the code in the switch/loop stops • Any code outside/after a switch/loop is then executed. 2(b) Two from: 2 • Functions are (JavaScript) objects with properties • Declared/initiated by the function statement • Used to save a section of code for later/repeated use • Set of statements (in JS code) that perform a task/calculation (1st) – Must have/with input/return output (1) • (Only) invoked/executed/run when called/invoked by other code. 2(c) Two from: 2 • Used to explain (JavaScript) code • Used to stop/prevent code being executed (when testing alternative code) • Used to make code more understandable/allows (future) programmers to follow/debug/understand code • Single line comments begin with // • Multi line comments begin with /* and end with */

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3 Describe the Agile method used to develop software. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 3 Six from: 6 One for at least four correctly identified stages: • List of stages i.e. Initiation, Planning, Documentation, Development, Support/maintenance Max two valid descriptions of activity in INITIATION e.g. • Create idea/vision for project • Discuss return on investment (ROI) • Identify team members are identified • Determine time/resources that are needed • Carry out feasibility study carried out/ determine if the project can be done Max two valid descriptions of activity in PLANNING by e.g. • Developers working with client/stakeholders/end-users • Specifications are written e.g. User/system/requirement specifications • Risks are considered/estimated • Product features are determined Max two valid descriptions of activity in DEVELOPMENT e.g.: • Development based on specifications • Occurs in sprints/iterations/incremental phases • Working software available at end of this phase • Working software has minimal functionality which will be built on in each sprint • Each iteration is tested Max two valid descriptions of activity in DOCUMENTATION e.g.: • Production of user documentation • Deployment to end-users • Handover with training to end-users • Software monitored for errors/problems Max two valid descriptions of activity in SUPPORT/MAINTENANCE e.g.: • Software withdrawn/decommissioned/end-of-life • Support for software stops • End-users notified of impending withdrawal of software • Software replaced by new release/version.

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4 Justify the use of lossy compression when storing and using bitmap images. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 4 Six from: 6 • (Lossy) compression of images reduces the amount data needed to represent the image while allowing the image to be reconstructed • (Lossy) compression of images reduces the file size • allows more images to be stored within a fixed amount of disk space/computer storage • allows transfer of (whole) image over networks/internet to be completed faster/in shorter space of time • image to be attached to email message without exceeding ISP max file size limit • allows image to be posted on social media sites which are optimised for mobile devices/data transfer over mobile communication systems • no fear of unauthorised use/stolen because image is degraded/has compression artefacts/effects (of lossy) compression/smaller file size allows commercial/copyright images to be posted on social media/web sites without • better user experience/not discouraging viewers (by reducing loading time of web pages) • Compression artefacts can be used by artists to enhance the visual impact of images.

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5 Objects in computer animations have properties. Describe the following properties. (a) Orientation ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (b) Transparency ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3]

Mark scheme: 5(a) Three from: 3 Max three from: • (Orientation) is a camera property that is set in a keyframe • Surface sets the target for the camera on the object surface • Provides a sense of gravity for the object • Space sets the target for the camera at the centre of the object. OR May be interpreted as ‘rotation which is a layer property’ Max three from: • Sets the x, y, and z rotation angles around a fixed point (the origin) in a layer • (Rotation) around the x-axis is the roll, yaw, angle. • (Rotation) around the y-axis is the inclination, pitch, angle. • (Rotation) around the z-axis is the azimuth, heading, angle. 5(b) Three from: 3 • (Sets the visibility of the objects/layers so) other layers in the display can be seen underneath. • Can be set to different percentages (of transparency/opacity) to change the visibility of layers underneath • Adjusted in keyframes to affect following frames • Can be adjusted so that some colours are removed/green screen effects • Can set a ‘transparency track’ in keyframes so transparency/opacity percentage changes between keyframes.

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6 Draw three different symbols used in a data flow diagram (DFD). For each symbol, state its purpose. Symbol 1 Purpose 1 .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Symbol 2 Purpose 2 .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... Symbol 3 Purpose 3 .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... [6]

Mark scheme: 6 Six from: 6 i.e. process, data store, data source, duplicate data source (the only ones in the syllabus), also allow arrow (and its purpose),and other valid DFD symbols. Symbols from the syllabus: Max three for DFD Symbols, max two per symbol: • Drawing of DFD Symbol (1st) – correct stated/statements of purpose matched to the symbol (1)

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7 Many companies have access control strategies to protect their data. Explain how the use of an access control strategy can minimise the risks to computer data. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 7 Six from: 6 • Access control ensures that users are who they say they are/confirms the identity of the user/authenticates the user • Ensures users have the appropriate access to data • Provides selective access to data/company controls who has access to what data • distribution of data is controlled/known • (Company) managers/staff/IT staff/users know who has/can have/is allowed access and who is not allowed access • Can be adapted (automatically) in response to changing conditions/change of staff (1st) – so that new employees can have access (1) – employees/staff who leave can no longer access data (1) • Can be adapted (automatically) in response to data breaches/analysis of risks (1st) – so that relevant employees/staff/users are isolated from the data (1) • Access control can be based on attribute of user within company (1st) – so that they can only access data appropriate for their job/task/role (1) – so that they can only access data depending on the location/time of access (1).

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8 Discuss the benefits and drawbacks of the use of cryptocurrencies by individuals. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 8 Eight from: 8 One for • valid description of cryptocurrency e.g.: a digital currency in which transactions are verified and recorded by a decentralised system using cryptography Benefits: Max six from: • Cannot be counterfeited so is not devalued by forgers • Transactions cannot be reversed by the sender for arbitrary reasons/without consent/assistance of recipient • Transactions can be anonymous so finances cannot be tracked/traced • Cost-effective option for immigrants who have left their homes to find work and wish to send payments to their families in other countries • Requires a private key/cryptographic password unique to each user for access so central government/organisation/corporation/bank cannot seize/freeze assets • Unaffected by government defaults on loans/bank collapses • Uses a “push” model prompting cryptocurrency holder to send exactly the amount to the seller without any other form of information • Not bound by exchange rates so no cost when transferring between countries • No need to change currency for transactions between countries • No transaction charges resulting in lower costs to senders/recipients • Transactions take place at the same speed regardless of where the sender and receiver are located. Drawbacks: Max six from: • Not backed by a government/central bank so subject to risks e.g. price volatility and regulatory intervention • Risk of centralised intervention/not be legal in some countries • Subject to volatility/significant price swings (as markets develop)/can lose a lot money quickly • Small part of the global financial ecosystem so few retailers/organisations accept it • Cannot easily be convert into cash/hard currency • Some governments have banned the use of cryptocurrencies • Risk of software errors affecting the chains leading to roll back/loss of transactions/value • Significant contribution to climate change due to power consumption. Max six if bullets/list of points.

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9 Botnets are software applications that are connected together over the internet. Describe how botnets attack computer systems. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 9 Six from: 6 • (Bot/malware/software application) installed on system without knowledge of owner/user • Bots set up as clients on system to communicate with controller device (on another device/peer-to-peer ) • Use internet to communicate with remote server • Can execute/run other malware to access files/gather data and send back to controller • Can carry out Denial-of-Service (DoS) attacks on servers/preventing legitimate use of files/data/services • Can send (spam/unwanted/fraudulent) disguised emails from infected devices/zombie computing devices with attached data/files/request for login credentials/financial details which can be used to gain access to system • Can distribute/direct spyware to gather user credentials/details/data and send to controller • Can use system resources and reduce its performance • Can compromise legitimate file/data storage systems so that data/files are damaged/lost.

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10 Alpha testing is carried out in the final stages of software development. Describe the process of alpha testing. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [6]

Mark scheme: 10 Six from: 6 • Carried out by the developers on the development site • Carry out review of the requirements specification • Carry out review of the design specification • Create/develop full test plans • Create/source test data • Carry out the test plan(s) • Record/log errors/defects/problems discovered during testing • Determine the cause of errors/defects/problems • Correct errors/detects/problems • Retest/repeat testing/iterative testing until errors/defects/problems are fixed/solved • Uses both white and black box testing.

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11 Discuss the benefits and drawbacks of using virtual servers for hosting websites. .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .......................................................................................................................................................... .................................................................................................................................................... [8]

Mark scheme: 11 Eight available. 8 One from: • Valid definition of virtual server e.g. virtualisation/emulation/software instance(s) of (different/multiple) (network) servers running on the same physical hardware of a server. Max six from: Benefits: • Companies can move their web hosting from own local physical servers to cloud-based virtual-servers – reducing their costs/maintenance/use of space • Physical hardware requirements are reduced as components/physical hardware shared by many virtual servers with reduction in costs/use of physical space/ maintenance • Set up/duplication/deployment of virtual servers is faster as physical hardware is already running/available/configured • Reduced down time taken for updates/upgrades in server/website software/hardware as new version can be set up and switched into use without interfering with old version • Backup/copying/restoration from failure of virtual servers/switching to backup/use of image-based backups is quicker/easier than restoring a physical server as physical hardware is already available/no time taken for restoring from tapes/disks Max six from: Drawbacks: • Data/web accounts may be at greater security risk due to sharing of hardware • High power computing requirements to run all virtual servers at peak performance else user experience is not optimal • Failure of physical component/hardware affects all virtual servers so hosted websites are all offline • Larger data storage facilities required as every virtual server is self- contained and has to have all OS/software for its exclusive use • Larger RAM requirement as each virtual server runs in/must have its own separate memory allocation • High bandwidth connections required to service all virtual servers at optimal performance levels. Max six if bullets/list of points.

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