📚 End of Unit 6: Exam-style Case Study Questions | 单元6考试风格案例研究题
This revision set provides exam-style case study questions for Cambridge International AS & A Level Computer Science Unit 6: Security, Privacy and Data Integrity. Each case presents a realistic scenario, followed by short-answer and extended-response questions similar to those in Paper 2 and Paper 3 style assessments. Model answers are given after each question so that you can self-check your understanding of encryption, authentication, validation, verification, data loss prevention and data protection legislation.
本复习集为剑桥国际AS与A Level计算机科学第6单元“安全、隐私与数据完整性”提供考试风格的案例研究题。每个案例给出一个真实场景，并附上Paper 2和Paper 3风格考试中常见的简答题与扩展题。每道题后提供参考答案，以便你自查对加密、身份验证、数据验证、数据核实、数据丢失预防和数据保护法律等关键概念的理解。
1. Hospital Patient Records | 医院病历
A hospital stores patient records on a central server. Doctors and nurses access records from wards, while reception staff can only view appointment times. The hospital has experienced an incident where a cleaner logged in using a doctor's account and viewed a patient's test results.
一家医院将病历存储在中央服务器上。医生和护士在病房访问记录，而前台工作人员只能查看预约时间。该医院发生了一起事件：一名清洁工使用医生账户登录，并查看了一名患者的检查结果。
(a) State two methods the hospital could use to prevent unauthorised access to patient records. (b) Explain why the use of strong individual passwords would not completely solve the problem in this scenario.
(a) 说明医院可以用来防止未经授权访问病历的两种方法。 (b) 解释为什么使用强个人密码并不能完全解决该场景中的问题。
(a) The hospital could introduce user access levels so each staff role has only the permissions needed for that role; for example, reception staff cannot view clinical notes. It could also enforce two-factor authentication using a smart card or biometric fingerprint scan linked to the staff member, which makes it harder for a cleaner to use a doctor's account.
(a) 医院可以引入用户访问级别，使每种员工角色只拥有该角色所需的权限；例如，前台人员不能查看临床记录。医院还可以使用与员工关联的智能卡或指纹生物识别来实施双因素身份验证，从而使清洁工更难使用医生的账户。
(b) Strong passwords only protect an account if they remain secret. In this case the cleaner may have watched the doctor type the password, or the doctor may have left the workstation logged in. Passwords do not verify that the person using the account is the genuine staff member, so the hospital also needs automatic screen locking, user access levels and audit logs.
(b) 强密码只有在保密的情况下才能保护账户。在本案例中，清洁工可能看到了医生输入密码，或者医生离开时未退出工作站。密码无法核实使用账户的人就是真正的员工，因此医院还需要自动锁屏、用户访问级别和审计日志。
2. Online Banking and Phishing | 网上银行与网络钓鱼
Customers of a bank receive emails claiming to be from the bank's security team. The emails ask customers to click a link and update their login details because their accounts have been suspended. Some customers follow the link and enter their credentials on a fake website.
一家银行的客户收到声称来自银行安全团队的电子邮件。邮件要求客户点击链接并更新登录信息，因为他们的账户已被暂停。一些客户点击链接，并在虚假网站上输入了凭据。
(a) Identify the type of security threat shown in this case and explain one sign that could indicate the email is fraudulent. (b) Describe how the bank can use two-factor authentication and HTTPS to protect customers.
(a) 指出该案例中显示的安全威胁类型，并解释一个可能表明电子邮件是欺诈的迹象。 (b) 描述银行如何使用双因素身份验证和HTTPS来保护客户。
(a) The threat is phishing, where an attacker sends fake emails pretending to be a legitimate organisation to trick users into revealing personal information. A sign of fraud is that the sender's email address may use a domain that is slightly different from the bank's real domain, or the message may contain spelling and grammar errors and a sense of urgency.
(a) 这种威胁是网络钓鱼，攻击者发送伪装成合法机构的虚假电子邮件，诱骗用户泄露个人信息。欺诈的一个迹象是发件人的电子邮件地址可能使用与银行真实域名略有不同的域名，或者邮件可能包含拼写和语法错误以及紧迫感。
(b) Two-factor authentication requires the customer to provide two different types of evidence before access is granted, such as a password and a one-time code sent to their mobile phone. Even if a phisher obtains the password, the second factor is still missing. HTTPS encrypts data transmitted between the customer's browser and the bank's server using SSL/TLS, so intercepted login details cannot be read by an attacker.
(b) 双因素身份验证要求客户在获得访问权限之前提供两种不同类型的证据，例如密码和发送到其手机的一次性验证码。即使网络钓鱼者获得了密码，第二个因素仍然缺失。HTTPS使用SSL/TLS对客户浏览器与银行服务器之间传输的数据进行加密，因此攻击者无法读取被截获的登录信息。
3. School Database and Access Rights | 学校数据库与访问权限
A school uses a management information system to store student attendance, grades, behaviour records and medical information. Teachers can edit grades, administrative staff can update contact details, parents can view their own child's reports, and students can view their own timetable.
一所学校使用管理信息系统存储学生的出勤、成绩、行为记录和医疗信息。教师可以编辑成绩，行政人员可以更新联系方式，家长可以查看自己孩子的报告，学生可以查看自己的课程表。
(a) Explain how user access levels protect data privacy in this system. (b) Describe one way the school can ensure that student data remains accurate and up-to-date.
(a) 解释用户访问级别如何在该系统中保护数据隐私。 (b) 描述学校可以确保学生数据保持准确和最新的一种方法。
(a) User access levels restrict what each user can view and modify according to their role. For example, a teacher cannot access another student's medical information if that permission is not granted, and a student cannot change their own grades. This reduces the risk of accidental or deliberate disclosure of private data to unauthorised users.
(a) 用户访问级别根据角色限制每个用户可以查看和修改的内容。例如，如果未授予权限，教师无法访问其他学生的医疗信息，学生也无法更改自己的成绩。这降低了私人数据被意外或故意泄露给未授权用户的风险。
(b) The school can use validation rules when data is entered, such as range checks on attendance percentages and format checks on date fields, combined with regular review by administrative staff. Verification methods like double entry of critical fields can also help reduce data entry errors.
(b) 学校可以在数据输入时使用验证规则，例如对出勤率进行范围检查，对日期字段进行格式检查，并结合行政人员的定期审查。像关键字段的双重输入这样的核实方法也有助于减少数据输入错误。
4. E-commerce Website and Malware | 电子商务网站与恶意软件
An online retailer suffers a malware infection after an employee opens an email attachment from an unknown sender. The malware spreads through the internal network and encrypts customer order files, demanding a ransom for their release.
一家在线零售商的一名员工打开了来自未知发件人的电子邮件附件，随后遭受恶意软件感染。该恶意软件在内部网络中传播，并加密了客户订单文件，要求支付赎金才能释放这些文件。
(a) State two types of malware and describe how each can affect a computer system. (b) Explain how anti-virus software and a firewall can reduce the risk of this type of incident.
(a) 说明两种恶意软件类型，并描述每种类型如何影响计算机系统。 (b) 解释防病毒软件和防火墙如何降低此类事件的风险。
(a) A virus attaches itself to a legitimate file or program and replicates when the file is opened, often corrupting or deleting data. Ransomware encrypts files on the infected system and demands payment for the decryption key, preventing the organisation from accessing its own data until the ransom is paid or backups are restored.
(a) 病毒附着在合法文件或程序上，并在文件打开时进行复制，通常会损坏或删除数据。勒索软件加密受感染系统上的文件，并要求支付解密密钥的赎金，使组织在支付赎金或恢复备份之前无法访问自己的数据。
(b) Anti-virus software scans files and email attachments for known malware signatures and can quarantine or delete infected items before they execute. A firewall monitors incoming and outgoing network traffic and can block unauthorised connections, preventing malware from communicating with external command-and-control servers or spreading through open ports.
(b) 防病毒软件扫描文件和电子邮件附件中的已知恶意软件特征码，并可以在受感染项目执行之前将其隔离或删除。防火墙监控传入和传出的网络流量，并可以阻止未经授权的连接，防止恶意软件与外部命令控制服务器通信或通过开放端口传播。
5. Wearable Fitness App and Data Privacy | 可穿戴健身应用与数据隐私
A wearable fitness app collects heart rate, sleep patterns, GPS location and dietary information from its users. The app developer plans to share anonymised user data with health insurance companies for research purposes.
一款可穿戴健身应用收集用户的心率、睡眠模式、GPS位置和饮食信息。该应用开发商计划与健康保险公司共享匿名化的用户数据用于研究。
(a) Explain two privacy concerns users might have about this data collection. (b) Describe two measures the app developer should implement to comply with data protection principles.
(a) 解释用户可能对这种数据收集产生的两个隐私担忧。 (b) 描述应用开发商应实施的两项措施以符合数据保护原则。
(a) First, location data can reveal where a user lives, works or visits regularly, which could be misused if the data is leaked. Second, health-related data such as heart rate and sleep patterns is sensitive personal information; if linked back to an individual, it could affect insurance premiums or employment decisions without the user's knowledge or consent.
(a) 首先，位置数据可能泄露用户居住、工作或经常访问的地点，如果数据泄露，可能会被滥用。其次，心率、睡眠模式等健康相关数据属于敏感个人信息；如果与个人身份关联，可能会在用户不知情或未同意的情况下影响保险费或就业决定。
(b) The developer should obtain clear, informed consent from users before collecting or sharing data, explaining exactly what data is collected and how it will be used. The developer should also use strong encryption when storing and transmitting data, and apply data minimisation so that only the data needed for the stated purpose is collected.
(b) 开发商应在收集或共享数据之前获得用户的明确知情同意，准确说明收集哪些数据以及如何使用。开发商还应在存储和传输数据时使用强加密，并应用数据最小化原则，只收集实现既定目的所必需的数据。
6. Cloud Storage for Legal Firm | 律师事务所的云存储
A law firm stores highly confidential case files in a cloud-based document management system. The firm is concerned about unauthorised access to files while stored on the cloud provider's servers and during transmission over the internet.
一家律师事务所将高度机密的案件文件存储在基于云的文档管理系统中。该事务所担心文件在云提供商服务器上存储期间以及通过互联网传输期间遭到未经授权的访问。
(a) Compare symmetric and asymmetric encryption for protecting data stored in the cloud. (b) Explain how hashing can be used to check whether a case file has been altered.
(a) 比较对称加密和非对称加密在保护云中存储数据方面的特点。 (b) 解释如何使用哈希来检查案件文件是否被篡改。
(a) Symmetric encryption uses a single secret key for both encryption and decryption. It is fast and efficient for encrypting large amounts of data at rest, but the key must be securely shared between the firm and the cloud provider. Asymmetric encryption uses a public key for encryption and a private key for decryption; it is more secure for exchanging keys over the internet but is slower and less efficient for encrypting very large files, so it is often used to encrypt a symmetric key rather than the data itself.
(a) 对称加密使用同一个秘密密钥进行加密和解密。它对于加密大量静态数据快速高效，但密钥必须在事务所和云提供商之间安全共享。非对称加密使用公钥加密、私钥解密；它在互联网上交换密钥时更安全，但加密非常大的文件时速度较慢、效率较低，因此通常用于加密对称密钥，而不是直接加密数据。
(b) Hashing takes the contents of a case file and produces a fixed-size digest. When the file is later retrieved, the hash value can be recalculated and compared with the stored hash. If the two values match, the file has very likely not been altered; if they differ, data integrity has been lost.
(b) 哈希接受案件文件的内容并生成固定大小的摘要。以后检索文件时，可以重新计算哈希值并与存储的哈希值进行比较。如果两个值匹配，则文件很可能未被篡改；如果不同，则数据完整性已丢失。
7. Airline Booking System and Data Validation | 航空公司订票系统与数据验证
An airline website allows customers to book flights by entering their full name, date of travel, passport number and number of passengers. The system must reduce the number of incorrect bookings caused by data entry errors.
一家航空公司网站允许客户通过输入全名、旅行日期、护照号码和乘客人数来预订航班。该系统必须减少因数据输入错误而导致的预订错误。
(a) Suggest validation checks for the date of travel, passenger name and passport number. (b) Describe how verification by double entry can reduce errors in this booking system.
(a) 为旅行日期、乘客姓名和护照号码建议合适的验证检查。 (b) 描述双重输入核实如何减少该订票系统中的错误。
(a) For the date of travel, a range or presence check can ensure the date is not in the past and is in a valid format. For the passenger name, a presence check should ensure the field is not empty, and a length check can prevent excessively long entries. For the passport number, a format check can ensure it matches the expected pattern of letters and digits, and a length check can prevent invalid character counts.
(a) 对于旅行日期，范围或存在性检查可以确保日期不是过去的日期且格式有效。对于乘客姓名，存在性检查应确保字段不为空，长度检查可以防止输入过长。对于护照号码，格式检查可以确保其符合预期的字母和数字模式，长度检查可以防止无效的字符数。
(b) Double entry requires the user to enter critical data twice, for example typing an email address or passport number in two separate fields. The system then compares the two entries and flags a mismatch. This reduces transcription errors because the chance of making exactly the same mistake twice is low.
(b) 双重输入要求用户两次输入关键数据，例如在两个单独的字段中输入电子邮件地址或护照号码。系统随后比较两次输入并标记不一致。这可以减少转录错误，因为两次犯完全相同错误的概率很低。
8. Social Media Platform and Denial of Service | 社交媒体平台与拒绝服务攻击
A social media platform is hit by a distributed denial-of-service (DDoS) attack. Users are unable to access the platform for several hours, and the company loses advertising revenue.
一个社交媒体平台遭到分布式拒绝服务（DDoS）攻击。用户数小时无法访问该平台，公司损失了广告收入。
(a) Explain how a DDoS attack affects the availability of the platform. (b) Describe two security measures the platform can implement to mitigate DDoS attacks.
(a) 解释DDoS攻击如何影响平台的可用性。 (b) 描述平台可以实施的两项安全措施以减轻DDoS攻击。
(a) A DDoS attack uses a botnet of many compromised devices to send a huge volume of bogus requests to the platform's servers at the same time. The servers become overloaded and cannot respond to legitimate user requests, so the service becomes unavailable to genuine customers.
(a) DDoS攻击使用由许多受感染设备组成的僵尸网络，同时向平台服务器发送大量虚假请求。服务器过载，无法响应合法用户请求，因此真实客户无法使用该服务。
(b) The platform can use a firewall configured to filter out traffic from suspicious IP addresses or block packets that do not follow expected patterns. It can also use a proxy server or content delivery network to absorb attack traffic and forward only legitimate requests to the main servers, helping to keep the core infrastructure available.
(b) 平台可以配置防火墙来过滤来自可疑IP地址的流量或阻止不符合预期模式的数据包。它还可以使用代理服务器或内容分发网络来吸收攻击流量，只将合法请求转发到主服务器，从而保持核心基础设施的可用性。
9. University Research Data and Backup Strategies | 大学研究数据与备份策略
A university research group collects 10 TB of experimental data and stores it on a local server. The group must protect against data loss from hardware failure, accidental deletion and fire or flood in the building.
一个大学研究小组收集了10 TB的实验数据，并将其存储在本地服务器上。该小组必须防止因硬件故障、意外删除以及建筑物火灾或洪水造成的数据丢失。
(a) Compare full, incremental and differential backup strategies for this data. (b) Explain the importance of off-site backup and a disaster recovery plan.
(a) 比较针对该数据的完全备份、增量备份和差异备份策略。 (b) 解释异地备份和灾难恢复计划的重要性。
(a) The table below summarises the three backup methods.
(a) 下表总结了三种备份方法。
| Backup type | What is
Published by TutorHao | A-Level Computer Science Revision Series | aleveler.com 广告 / Sponsored 现货 Cambridge International AS & ALevel IT Coursebook剑桥国际IGC… 计算机 备考教辅 · 正版现货 · 与本文内容相关 查看详情 / View on Taobao参考价 ¥467.0更多咨询请联系16621398022（同微信） 备考资讯每日更新，关注不错过 考纲变化 · 科目分析 · 学习方法  在微信里长按二维码识别关注 或截图后用「扫一扫 → 相册」选择本图 公众号：tutorhao |
|---|