References only, not question text. Open Official paper ↗ where Cambridge publishes the paper,
or see the official Cambridge past-papers page; for other papers, ask your
school. “Paper 42” means Paper 4, variant 2.
Practice questions
Original questions written by HomiLabs in the style of the exam, with answers and mark schemes. They are not
Cambridge past paper questions and have not been reviewed by Cambridge. Try each one before opening the answer.
Q1Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Core · Paper 1 style · 3 marks
(a)Explain the difference between the internet and the World Wide Web.[2]
(b)State the language in which web pages are written so that a browser can display them.[1]
Show answer
(a) The internet is the global network of interconnected networks/computers (the infrastructure); the World Wide Web is the collection of websites and web pages that are accessed using the internet.
1 mark for internet = network infrastructure. 1 mark for WWW = web pages/websites accessed over the internet.
(b) HTML (HyperText Markup Language)
1 mark.
Q2Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Core · Paper 1 style · 4 marks
(a)A parent types this URL to find school fees:https://www.greenvalleyschool.edu.pk/admissions/fees.htmlIdentify the protocol, the domain name and the web page/file name in this URL.[3]
(b)State what /admissions/ represents in the URL.[1]
(b) The folder/directory (path) on the web server where the page is stored.
1 mark.
Q3Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Core · Paper 1 style · 4 marks
(a)Describe the difference between a session cookie and a persistent cookie.[2]
(b)Give two uses of cookies.[2]
Show answer
(a) A session cookie is stored temporarily (in memory) and is deleted when the browser is closed; a persistent cookie is saved on the user's storage and remains until its expiry date or until the user deletes it.
1 mark for each type described.
(b) Any two, e.g. storing items in a virtual shopping basket; saving login details so the user stays logged in; remembering user preferences such as language; tracking pages visited to show targeted adverts; storing the progress through a website.
1 mark for each use.
Q4Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Core · Paper 1 style · 3 marks
(a)State three functions of a web browser.[3]
Show answer
(a) Any three, e.g. renders/displays HTML as web pages; stores bookmarks/favourites; records user history; allows use of multiple tabs; stores and manages cookies; provides navigation tools (back, forward, refresh); has an address bar; sends requests for web pages using HTTP/HTTPS; runs scripts such as JavaScript.
1 mark for each function.
Q5Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Standard · Paper 1 style · 5 marks
(a)Zainab types the URL of an online newspaper into her browser. Describe how the Domain Name Server (DNS) is used so that the web page can be found and displayed.[5]
Show answer
(a) The browser sends the domain name/URL to a DNS server; the DNS server looks up the domain name in its database to find the matching IP address; if it does not have it, it passes the request to another DNS server (higher in the hierarchy); the IP address is returned to the browser; the browser uses the IP address to send a request to the web server; the web server sends the web page (HTML) back; the browser renders it.
1 mark each for any five points in a logical order.
Q6Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Standard · Paper 1 style · 4 marks
(a)An online clothing shop uses HTTPS instead of HTTP. Explain the difference between HTTP and HTTPS.[2]
(b)Explain why it is important that the shop uses HTTPS when customers pay.[2]
Show answer
(a) Both are protocols used to transfer web pages between server and browser; HTTPS is secure – it uses SSL/TLS to encrypt the data sent, whereas HTTP data is not encrypted.
1 mark: both are protocols for transferring web pages / rules for communication. 1 mark: HTTPS encrypts using SSL/TLS.
(b) Card and personal details are encrypted, so if the data is intercepted it cannot be understood; it also confirms (via the certificate) that the customer is connected to the genuine shop server.
1 mark: data encrypted / meaningless if intercepted. 1 mark: payment details protected / authenticity of website.
Q7Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Standard · Paper 1 style · 4 marks
(a)An online bookshop in Peshawar uses cookies. Bilal adds three books to his basket, closes the browser by mistake, then opens the site again the next day. His basket still contains the books and he is still logged in. Explain how cookies have made this possible.[3]
(b)Explain why a session cookie could not have done this.[1]
Show answer
(a) The website stored a cookie (a small text file) on Bilal's computer; it was a persistent cookie, so it was not deleted when the browser closed; it contained/identified his basket items and login details; when he returned, the browser sent the cookie to the website, which read it and restored his basket and session.
1 mark each for any three points.
(b) A session cookie is deleted when the browser is closed, so the basket and login information would have been lost.
1 mark.
Q8Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Standard · Paper 1 style · 4 marks
(a)A web browser has many functions. Describe how each of these helps a user.(i) Bookmarks(ii) History(iii) Tabs(iv) Address bar[4]
Show answer
(a)(i) Bookmarks save the address of a favourite page so it can be opened again quickly.(ii) History records the pages visited, so the user can find and return to a page they saw earlier.(iii) Tabs let several web pages be open at the same time in one window and switched between.(iv) The address bar lets the user type a URL to go directly to a web page (and shows the current page's URL).
1 mark for each description.
Q9Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Challenge · Paper 1 style · 4 marks
(a)A student says: 'A URL and an IP address are the same thing.' Explain why the student is wrong.[2]
(b)Explain why websites use URLs even though computers use IP addresses to find web servers.[2]
Show answer
(a) A URL is a text-based address of a web page/resource that is easy for humans to remember; an IP address is a numeric address that identifies a device (the web server) on the network.
1 mark for URL description. 1 mark for IP address description.
(b) URLs (domain names) are easier for people to remember and type than a string of numbers; DNS converts the domain name into the IP address, so the web server's IP address can change without the URL changing.
1 mark: easier to remember. 1 mark: DNS converts to IP / IP can change while URL stays the same.
Q10Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Challenge · Paper 1 style · 6 marks
(a)Explain how a web page is requested, located and displayed when a user types a URL into a web browser. Your answer should refer to the browser, DNS, IP address, web server, HTTP/HTTPS and HTML.[6]
Show answer
(a) The user types the URL into the address bar of the browser; the browser sends the domain name to a DNS server; DNS looks up / finds the matching IP address (asking other DNS servers if needed); the IP address is sent back to the browser; the browser sends an HTTP/HTTPS request to the web server at that IP address; the web server sends the web page files (HTML) back using HTTP/HTTPS; the browser renders the HTML and displays the page (and may store cookies).
1 mark each for any six points in a logical sequence.
Q11Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Challenge · Paper 1 style · 6 marks
(a)A sports news website uses persistent cookies to personalise the stories it shows. Explain how a persistent cookie allows the website to personalise the stories.[3]
(b)Give two reasons why some users delete persistent cookies, and one consequence of doing so.[3]
Show answer
(a) The cookie stores data such as the user's preferences and the pages/stories they have viewed; it remains on the user's device between visits; when the user returns, the browser sends the cookie to the website, which reads it and shows stories that match the stored preferences (e.g. their favourite team).
1 mark each for three points.
(b)Reasons (any two): privacy concerns about their browsing being tracked; to stop targeted adverts; to protect stored login details on a shared computer; to free storage.Consequence (any one): preferences are lost/have to be set again; the user must log in again; saved basket items are lost.
1 mark for each reason (max 2), 1 mark for a consequence.
Q12Internet, WWW, URLs, browsers, HTTP(S), DNS and cookies · Challenge · Paper 1 style · 4 marks
(a)A user in Quetta types the domain name of a small travel website. The first DNS server contacted does not have this domain name in its database. Describe what happens next until the browser receives a result.[3]
(b)Explain why the result of the look-up is often stored by the DNS server or browser for a short time.[1]
Show answer
(a) The DNS server passes/forwards the request to another DNS server (higher up the hierarchy); this continues until a DNS server that holds the domain name is found; that server sends the IP address back (through the chain) to the browser. If no DNS server has the domain name, an error message is returned to the browser (e.g. the site cannot be found).
1 mark: request forwarded to another DNS server. 1 mark: IP address found and returned to browser. 1 mark: error returned if domain not found.
(b) So that the next request for the same domain can be answered quickly without asking other DNS servers again.
1 mark.
Q13Security solutions (SSL, firewalls, proxy servers, backups) · Core · Paper 1 style · 3 marks
(a)A small office in Hyderabad installs a firewall between its network and the internet. State three things the firewall does.[3]
Show answer
(a) Any three, e.g. monitors incoming and outgoing traffic; checks traffic against a set of rules/criteria; blocks traffic that does not meet the rules; can block access to specified websites/IP addresses; can log/record traffic; can alert the user to suspicious traffic; helps prevent hacking/malware entering.
1 mark for each function.
Q14Security solutions (SSL, firewalls, proxy servers, backups) · Core · Paper 1 style · 3 marks
(a)A shop in Quetta keeps its sales records on one computer. Describe what is meant by a backup.[1]
(b)Explain why the shop should keep its backup in a different location, for example in cloud storage.[2]
Show answer
(a) A copy of the data stored separately (on another device or location) so it can be restored if the original is lost or damaged.
1 mark.
(b) If the shop's computer is damaged, stolen or destroyed (e.g. by fire or flood), a backup kept in the same place could be lost too; an off-site/cloud backup will still be available to restore the data.
1 mark: same event could destroy both copies. 1 mark: off-site copy survives so data can be restored.
Q15Security solutions (SSL, firewalls, proxy servers, backups) · Core · Paper 1 style · 4 marks
(b)Give one example of biometric authentication and one drawback of biometric methods.[2]
Show answer
(a) The user first enters their password/username; then a second step is needed, such as a one-time code sent to their registered phone or email, which must be entered before access is given.
1 mark: password entered first. 1 mark: second code/factor sent to another device must also be entered.
(b) Example: fingerprint, face recognition, iris/retina scan, voice recognition. Drawback (any one): can fail if the body part is injured/dirty or in poor light; biometric data cannot be changed if it is stolen; equipment can be expensive.
1 mark for example, 1 mark for drawback.
Q16Security solutions (SSL, firewalls, proxy servers, backups) · Standard · Paper 1 style · 5 marks
(a)Describe how SSL (Secure Socket Layer) is used to set up a secure connection between a web browser and a web server.[5]
Show answer
(a) The browser requests a secure connection from the web server; the browser asks the server to identify itself; the server sends a copy of its digital/SSL certificate (which includes its public key); the browser checks the certificate is authentic/valid (issued by a trusted authority); if valid, the browser sends a message to the server (acknowledgement); the server and browser agree encryption and a secure session begins; data sent is then encrypted.
1 mark each for any five points.
Q17Security solutions (SSL, firewalls, proxy servers, backups) · Standard · Paper 1 style · 4 marks
(a)A college network uses both a firewall and a proxy server. Describe two differences between what a firewall does and what a proxy server does.[4]
Show answer
(a) Any two pairs, e.g. a firewall checks/filters traffic against rules and blocks it, whereas a proxy server acts as an intermediary that makes requests to web servers on behalf of the user; a proxy hides the user's IP address from web servers, a firewall does not; a proxy can cache (store) web pages to speed up later requests, a firewall does not; a firewall can be software on the computer as well as hardware, a proxy is a separate server that the requests pass through.
For each difference, 1 mark for the firewall point and 1 mark for the matching proxy point.
Q18Security solutions (SSL, firewalls, proxy servers, backups) · Standard · Paper 1 style · 3 marks
(a)A school database holds students' names, marks and medical notes. Explain how access levels can be used to protect this data.[3]
Show answer
(a) Different users are given different access rights depending on their role; e.g. teachers can view and edit marks but cannot see medical notes, while the nurse can view medical notes; students can only view their own marks/read-only; this means users can only see or change the data they need, reducing accidental or deliberate misuse.
1 mark each for any three points, at least one applied to the school context.
Q19Security solutions (SSL, firewalls, proxy servers, backups) · Standard · Paper 1 style · 4 marks
(a)Describe how anti-malware software protects a computer.[3]
(b)Explain why the anti-malware software should be set to update automatically.[1]
Show answer
(a) It scans files/data (when downloaded/opened or on a schedule); it compares them against a database of known malware (signatures); it can use heuristic checking to spot suspicious behaviour; infected files are quarantined or deleted; it can warn the user.
1 mark each for any three points.
(b) New malware is created all the time, so the database of known malware must be kept up to date to detect it.
1 mark.
Q20Security solutions (SSL, firewalls, proxy servers, backups) · Challenge · Paper 1 style · 6 marks
(a)A bank in Karachi is launching an online banking website. Identify three different security solutions the bank should use and explain how each one protects customers.[6]
Show answer
(a)Any three, e.g.- SSL/HTTPS: encrypts data sent between browser and server, so intercepted account details cannot be read;- two-step verification: a code is sent to the customer's phone, so a stolen password alone does not give access;- firewall: filters traffic to the bank's servers, blocking unauthorised access/hacking attempts;- anti-malware on servers: detects and removes malware that could steal data;- access levels: staff only see the customer data needed for their job;- automatic logout/session timeouts: an unattended session is closed;- proxy server: hides internal server addresses and filters requests.
For each of three solutions: 1 mark for identifying it, 1 mark for explaining how it protects customers.
Q21Security solutions (SSL, firewalls, proxy servers, backups) · Challenge · Paper 1 style · 5 marks
(a)A university network sends all web requests through a proxy server. Explain how the proxy server improves both the speed and the security of web access for students.[4]
(b)The proxy server cannot stop a student's laptop from being infected by a virus on a USB flash drive. Name a security solution that would.[1]
Show answer
(a)Speed: the proxy caches web pages that have been requested; when another student requests the same page it is sent from the cache rather than from the internet, so it loads faster and reduces internet traffic.Security: web servers only see the proxy's IP address, so students' devices are hidden from attackers; the proxy can filter/block requests to unsafe or banned websites; attacks such as DDoS hit the proxy rather than the university's servers.
Up to 2 marks for speed, up to 2 marks for security.
(b) Anti-malware / anti-virus software on the laptop.
1 mark.
Q22Security solutions (SSL, firewalls, proxy servers, backups) · Challenge · Paper 1 style · 4 marks
(a)Sana receives an email that appears to come from her mobile network company. It asks her to log in using a link. Describe three checks Sana could make to decide whether the email and website are genuine.[3]
(b)Explain why checking for HTTPS alone is not enough to show that a website is genuine.[1]
Show answer
(a) Any three, e.g. check the sender's email address matches the real company; check the spelling and tone of the email (errors, urgent threats, generic greeting suggest it is fake); hover over / check the link URL to see whether it matches the genuine domain name; check the website uses HTTPS and has a valid certificate (padlock); do not use the link – type the known address instead and log in there.
1 mark for each check.
(b) A fake website can also obtain a certificate and use HTTPS; HTTPS only shows the connection is encrypted, not who owns the site.
1 mark.
Q23Cyber security threats · Core · Paper 1 style · 4 marks
(a)Name the type of malware described by each statement.(i) It replicates itself and spreads through a network without needing a host file or user action.(ii) It encrypts the user's files and demands payment to unlock them.(iii) It records the user's key presses and sends them to a third party.(iv) It is disguised as useful software but contains harmful code.[4]
Show answer
(a) (i) Worm (ii) Ransomware (iii) Spyware (iv) Trojan horse
1 mark for each.
Q24Cyber security threats · Core · Paper 1 style · 4 marks
(a)Describe phishing.[2]
(b)Describe pharming and explain why it can be harder for a user to notice than phishing.[2]
Show answer
(a) Legitimate-looking emails/messages are sent to users; they contain a link or attachment that takes the user to a fake website or asks them to give personal details, which are then stolen.
1 mark: fake but genuine-looking email/message. 1 mark: tricks user into giving personal data / clicking link to fake site.
(b) Malicious code is installed on the user's computer or a DNS server is altered, so the user is redirected to a fake website even when they type the correct URL; it is harder to notice because the user has not clicked any suspicious link – the address they typed looks correct.
1 mark: malicious code / altered DNS redirects to fake site. 1 mark: happens even when correct URL is typed so user is not warned.
Q25Cyber security threats · Standard · Paper 1 style · 5 marks
(a)On the day exam results are released, a results website becomes unavailable because of a distributed denial of service (DDoS) attack. Describe how a DDoS attack is carried out.[4]
(b)State one way the results website could reduce the effect of a DDoS attack.[1]
Show answer
(a) The attacker infects many computers with malware to create a botnet; the attacker instructs the botnet computers to send very large numbers of requests to the results web server at the same time; the server/network cannot handle all the requests; it slows down or crashes, so genuine students cannot access the results.
1 mark each for four points.
(b) Any one, e.g. use a firewall/proxy server to filter or block traffic from suspicious IP addresses; limit the number of requests from one address; use extra servers to share the load.
1 mark.
Q26Cyber security threats · Standard · Paper 1 style · 4 marks
(a)Describe what is meant by a brute-force attack on a user's account.[2]
(b)Describe two ways a website can reduce the risk of a successful brute-force attack.[2]
Show answer
(a) An attacker tries many different passwords one after another, (often using software to try every combination or a list of common passwords) until the correct one is found.
1 mark: repeatedly trying passwords. 1 mark: systematically/automatically until correct one found.
(b) Any two, e.g. require strong passwords (long, mix of letters, numbers and symbols); lock the account after a set number of failed attempts; use two-step verification; add a delay between attempts.
1 mark for each method.
Q27Cyber security threats · Challenge · Paper 1 style · 5 marks
(a)A traveller connects to free Wi-Fi at an airport and logs in to an email account that does not use encryption. Describe how data interception could take place.[3]
(b)Explain how encryption reduces the impact of data interception.[2]
Show answer
(a) An attacker uses a packet sniffer (or a fake Wi-Fi access point) to monitor data sent over the network; the data packets are intercepted/copied as they travel between the traveller's device and the server; the attacker examines the packets to read the username, password and messages.
1 mark each for three points.
(b) The data is encrypted before it is sent, so if it is intercepted it is meaningless/cannot be understood; only the intended receiver has the key to decrypt it. (Encryption does not stop interception.)
1 mark: intercepted data cannot be understood. 1 mark: only receiver with the key can decrypt / it does not prevent interception itself.
Q28Cyber security threats · Challenge · Paper 1 style · 5 marks
(a)An office worker receives a phone call from someone claiming to be from the IT department. The caller says there is an urgent problem and asks for the worker's password. Identify this type of threat.[1]
(b)Explain why this type of threat can succeed even when the company has a firewall and anti-malware software.[2]
(c)Suggest two ways the company could reduce the risk of this threat.[2]
Show answer
(a) Social engineering
1 mark.
(b) It targets people rather than the technology; the worker is manipulated (e.g. by urgency, fear or trust in authority) into giving the password voluntarily, so the attacker logs in as a legitimate user and the technical defences are not triggered.
1 mark: exploits human behaviour/trust. 1 mark: attacker gets genuine credentials so firewall/anti-malware cannot detect it.
(c) Any two, e.g. train staff never to give passwords to anyone, including IT staff; have a policy to verify callers by calling back on a known number; use two-step verification so a password alone is not enough; report suspicious calls.
1 mark for each suggestion.
Q29HTML structure and presentation (old syllabus) · Core · Paper 1 style · 6 marks
The webmaster of a school in Quetta is building a notice page for the school website using HTML.
(a)State what is meant by the structure of a web page written in HTML.[1]
(b)State what is meant by the presentation of a web page.[1]
(c)Give two examples of presentation that the webmaster could set for the school's notice page.[2]
(d)For each change below, state whether it changes the structure or the presentation of the notice page.(i) A new paragraph giving the date of the sports day is added.(ii) The headings are made larger and changed to dark blue.[2]
Show answer
(a) The structure is the layout and content of the page: which elements it contains (headings, paragraphs, images, links, tables) and where they appear.
1 mark for: the layout / content / elements of the page and where they are placed (e.g. headings, paragraphs, images).
(b) The presentation is the formatting or style of the content, for example its colours, fonts and text sizes.
1 mark for: how the content looks / its formatting or style (colour, font, size, background).
(c) Any two of: the background colour; the font (typeface) of the text; the text size; the colour of the headings; borders or spacing around elements.
1 mark each for any two valid presentation features (colour, font, font size, background, border, alignment/spacing).
(d)(i) Structure(ii) Presentation
1 mark each: (i) structure – new content/element added to the page; (ii) presentation – only the size and colour (style) of existing content change.
Q30HTML structure and presentation (old syllabus) · Challenge · Paper 1 style · 8 marks
Part of the HTML file for the home page of an online shop in Karachi is shown below. Line numbers are given for reference only.1 <html>2 <head>3 <title>Bazaar Deals</title>4 <link rel="stylesheet" href="shop.css">5 </head>6 <body>7 <h1 style="color: green;">Eid Sale</h1>8 <p>All brass lamps are 20% off this week.</p>9 <img src="lamp.jpg" alt="Brass lamp">10 </body>11 </html>
(a)Identify the two lines of this file that deal with presentation rather than structure.[2]
(b)Describe what line 4 does when the page is loaded in a browser.[2]
(c)The shop has 30 pages and wants every main heading on all of them to be green. Explain why it is better to put this rule in shop.css than to use a style attribute like the one on line 7 in every page.[3]
(d)State where the text in line 3 is displayed by the browser.[1]
1 mark: the link to the stylesheet (line 4). 1 mark: the inline style attribute on the heading (line 7).
(b) It tells the browser to load the external stylesheet file shop.css and apply the presentation rules in it (colours, fonts, sizes) to the elements of this page.
1 mark: links / loads the external file shop.css. 1 mark: the styles in it are applied to the page's content.
(c) If the rule is in shop.css it is written once and every page that links to the file uses it, so all 30 headings look the same. To change the colour later, only one line in one file needs editing instead of 30 pages, which saves time and avoids missing a page. It also keeps the HTML files containing only structure, so they are shorter and easier to maintain.
1 mark each for any three of: written once / reused by all pages; consistent appearance; a later change is made in one place only; less chance of error (missing a page); HTML kept for structure only / shorter, easier to maintain; smaller total download as the CSS file can be cached.
(d) In the browser tab (title bar), not in the body of the page.
1 mark: browser tab / title bar.
Q31Digital currency and blockchain · Standard · Paper 1 style · 5 marks
(a)Describe what is meant by a digital currency.[2]
(b)Describe how blockchain is used to record digital currency transactions.[3]
Show answer
(a) A currency that exists only in electronic/digital form (it has no physical coins or notes); it can be used to pay for goods and services and is transferred electronically between users.
1 mark: exists only digitally. 1 mark: used/transferred electronically to make payments.
(b) Each transaction is stored in a block with a time-stamp; each block contains the hash value of the previous block, so the blocks are linked in a chain; copies of the blockchain are stored on many computers in a decentralised network; new transactions are added to every copy and none can be removed.
1 mark each for any three points.
Q32Digital currency and blockchain · Challenge · Paper 1 style · 5 marks
(a)A charity in Lahore is considering using a blockchain to record donations. Explain why it is very difficult for someone to change an earlier record in a blockchain without being detected.[4]
(b)State one benefit to the charity's donors of using a blockchain.[1]
Show answer
(a) Each block contains its own hash value and the hash of the previous block; changing data in a block changes its hash; this no longer matches the 'previous hash' stored in the next block, so the chain is broken and the change is detected; to hide the change every following block would have to be changed; and because many computers hold copies of the chain, the altered copy would not match the others and would be rejected.
1 mark each for any four points.
(b) Any one, e.g. donations are transparent and can be checked by anyone; records cannot be secretly altered, so donors can trust how money is recorded.
1 mark.
Similar questions
Questions that test the same subtopic in different years, grouped so you can work on one skill at a time.
References only: find each question in its paper (official link where available, otherwise through your school).
Internet, WWW, URLs, browsers, HTTP(S), DNS and cookiesBanker8 questions · 8/9 sessions
