MCQ Questions PDF

What is a primary advantage of using a synchronous approach for API calls in a low-traffic system? A. Reduced complexity in implementation B. Improved scalability for high-traffic scenarios C. Enhanced fault tolerance and resilience D. Delayed response times for users ANSWER: A # Explanation: A sync...

What is a primary advantage of using a synchronous approach for API calls in a low-traffic system? A. Reduced complexity in implementation B. Improved scalability for high-traffic scenarios C. Enhanced fault tolerance and resilience D. Delayed response times for users ANSWER: A # Explanation: A synchronous approach simplifies the implementation as the request-response cycle is straightforward, making it suitable for low-traffic systems where managing complexity is crucial. Which of the following is a key disadvantage of the asynchronous approach in high-traffic systems? A. Increased risk of timeout errors B. Requires additional infrastructure for task queues and workers C. Simplified error handling D. Immediate user feedback on requests ANSWER: B # Explanation: The asynchronous approach necessitates additional infrastructure, such as task queues and worker processes, increasing the system's complexity and maintenance requirements. In the context of database design, what is a main benefit of a normalized schema in a relational database? A. Faster read performance due to reduced joins B. Simplified data retrieval with embedded documents C. Reduced data redundancy and improved data integrity D. Increased storage requirements for duplicate data ANSWER: C # Explanation: A normalized schema minimizes data redundancy and enhances data integrity by organizing data into related tables, following principles of database normalization. Why might a denormalized schema be preferred in a NoSQL database for certain applications? A. To eliminate the need for data replication B. To optimize read performance by reducing the number of joins C. To ensure strict data integrity and consistency D. To simplify the database normalization process ANSWER: B # Explanation: Denormalized schemas are used to enhance read performance by embedding related data within a single document, thereby reducing the need for complex joins. What is a key trade-off when choosing between synchronous and asynchronous data flow approaches? A. Synchronous offers better scalability, while asynchronous simplifies implementation B. Synchronous provides real-time responses, whereas asynchronous improves scalability C. Synchronous requires more infrastructure, while asynchronous reduces complexity D. Synchronous is more fault-tolerant, while asynchronous increases timeout risks ANSWER: B # Explanation: Synchronous data flow allows for real-time responses, making it suitable for low-traffic systems, whereas asynchronous data flow enhances scalability by handling high traffic through task queuing and processing. Which of the following best describes the role of middleware in JWT validation within the backend? A. It generates JWT tokens for authenticated users B. It stores JWT tokens securely on the client side C. It intercepts requests to extract and validate JWT tokens before processing D. It handles the encryption and decryption of user credentials ANSWER: C # Explanation: Middleware acts as an intermediary that intercepts incoming requests, extracts the JWT from the Authorization header, validates it, and attaches user details to the request context before passing it to the subsequent handlers. What is the primary purpose of attaching user details to the request context after validating a JWT? A. To store user credentials for future requests B. To enable role-based access control (RBAC) within the backend C. To encrypt the JWT token for enhanced security D. To log user activities for auditing purposes ANSWER: B # Explanation: Attaching user details to the request context facilitates role-based access control by providing necessary information about the user's permissions and roles to the backend services. In an asynchronous system design, what is the role of a worker process? A. To handle real-time API requests from users B. To monitor and manage the task queue by processing tasks and interacting with the black box C. To store JWT tokens securely on the server side D. To validate user credentials against the database ANSWER: B # Explanation: Worker processes are responsible for retrieving tasks from the task queue, executing them (such as invoking the black box), and handling the responses, thereby enabling asynchronous processing. Which storage method is recommended for JWT tokens on the client side to mitigate the risk of token theft? A. Local storage with no security measures B. Session storage with secure attributes C. HTTP-only cookies with Secure flags D. Storing tokens in plain text files on the device ANSWER: C # Explanation: Storing JWT tokens in HTTP-only cookies with Secure flags prevents access to the tokens via JavaScript, mitigating the risk of token theft through XSS attacks. What should the backend do if it receives a request with an expired JWT token? A. Renew the token and proceed with the request B. Ignore the token and authorize the user C. Return a 401 Unauthorized response D. Redirect the user to the login page ANSWER: C # Explanation: If the JWT token is expired, the backend should reject the request and return a 401 Unauthorized response to indicate that the client needs to re-authenticate. During the authentication process, what is the benefit of performing a preliminary check for an existing Authorization header? A. It allows bypassing all security validations B. It ensures that the user is always redirected to the login page C. It optimizes performance by avoiding unnecessary database queries for authenticated users D. It enables storing user passwords in the token ANSWER: C # Explanation: A preliminary check for an existing Authorization header allows the system to validate the JWT and authorize the user without querying the database, thereby improving performance. What is a common method for signing JWT tokens to ensure their integrity and authenticity? A. Using plain text encoding B. Encrypting the token with a symmetric key C. Signing the token with a private key or shared secret D. Storing the token in a public repository ANSWER: C # Explanation: JWT tokens are signed using a private key or shared secret to ensure that they cannot be tampered with and to verify the token's authenticity. Why is it important to set an expiration time (`exp`) in a JWT token's payload? A. To increase the token's size for better security B. To allow the token to be used indefinitely C. To limit the token's validity period, enhancing security D. To store user-specific claims within the token ANSWER: C # Explanation: Setting an expiration time limits how long a JWT token is valid, reducing the risk of token misuse if it is compromised. What should a developer configure to ensure that all HTTP traffic is securely transmitted over HTTPS? A. Disable SSL/TLS on the server B. Redirect all HTTP traffic to HTTPS C. Allow mixed content by enabling both HTTP and HTTPS D. Use HTTP for initial authentication and HTTPS for subsequent requests ANSWER: B # Explanation: Redirecting all HTTP traffic to HTTPS ensures that all data transmitted between the client and server is encrypted, maintaining data confidentiality and integrity. In the context of handling user credentials, why is it recommended to use secure password hashing with salting? A. To make the password storage process faster B. To prevent attackers from easily cracking hashed passwords C. To allow storing plain text passwords securely D. To eliminate the need for password complexity requirements ANSWER: B # Explanation: Using secure password hashing with salting adds randomness to the hashing process, making it significantly harder for attackers to crack the passwords using techniques like rainbow tables. What is the main purpose of implementing token expiration policies in an authentication system? A. To allow tokens to be reused multiple times B. To increase the duration a token remains valid C. To limit the window of opportunity for token misuse D. To simplify token generation processes ANSWER: C # Explanation: Token expiration policies ensure that tokens are only valid for a limited period, reducing the risk associated with compromised tokens by limiting the time they can be used maliciously. Which component in the data flow is responsible for generating and signing JWT tokens upon successful authentication? A. The client application B. The frontend server C. The backend authentication service D. The task queue system ANSWER: C # Explanation: Upon successful authentication, the backend authentication service is responsible for generating and signing JWT tokens using a private key or shared secret before sending them to the client. What is a key consideration when choosing between Kafka and AWS SQS for implementing a task queue in an asynchronous system? A. Kafka is suitable for low-durability messaging, while AWS SQS offers high durability B. Kafka provides high durability and distributed messaging, whereas AWS SQS is better for simpler setups C. AWS SQS requires more complex setup compared to Kafka D. Both Kafka and AWS SQS offer identical features and scalability ANSWER: B # Explanation: Kafka is known for its high durability and support for distributed messaging, making it suitable for large-scale systems, while AWS SQS is often preferred for simpler integrations requiring reliable message queuing without the complexity of Kafka. In the authentication flow, what should the backend do if no Authorization header is present in the incoming request? A. Automatically authorize the user without checks B. Return a 401 Unauthorized response immediately C. Query the database or a third-party service to validate the provided credentials D. Generate a new JWT token without authentication ANSWER: C # Explanation: If no Authorization header is present, the backend should proceed to validate the user's credentials by querying the database or a third-party authentication service to ensure the user is legitimate. What security measures should developers implement to protect against Cross-Site Scripting (XSS) attacks in the context of token storage? A. Store tokens in local storage without restrictions B. Use HTTP-only cookies and implement input sanitization C. Allow JavaScript access to tokens for easier manipulation D. Disable HTTPS to prevent token interception ANSWER: B # Explanation: Using HTTP-only cookies prevents JavaScript from accessing the tokens, and input sanitization helps mitigate XSS attacks by ensuring that malicious scripts cannot be injected into the application. Why is it important to implement robust error handling for expired or invalid tokens in the backend? A. To enhance user experience by providing detailed error messages B. To prevent unauthorized access and maintain system security C. To allow expired tokens to be reused safely D. To simplify the authentication logic in the frontend ANSWER: B # Explanation: Robust error handling ensures that unauthorized access attempts are effectively blocked and that the system remains secure by properly managing expired or invalid tokens. What is the benefit of using role-specific claims within a JWT token? A. It eliminates the need for token expiration B. It allows for granular access control based on user roles C. It increases the token's size unnecessarily D. It simplifies the token generation process ANSWER: B # Explanation: Including role-specific claims in a JWT token enables the backend to enforce granular access control by determining what resources and actions the user is authorized to access based on their role. How does the preliminary authorization check improve performance in the authentication flow? A. By caching user credentials on the client side B. By allowing the system to bypass database queries for authenticated users with valid tokens C. By increasing the complexity of the authentication logic D. By storing all user data in the JWT token ANSWER: B # Explanation: The preliminary authorization check allows the system to validate existing tokens and authorize users without making additional database queries, thereby enhancing performance. What should the backend's response be when a JWT token fails signature verification? A. Grant access and log the event B. Return a 401 Unauthorized response C. Ignore the token and proceed with default permissions D. Refresh the token automatically ANSWER: B # Explanation: If a JWT token fails signature verification, it indicates that the token may have been tampered with or is invalid. The backend should reject the request and return a 401 Unauthorized response. In the context of secure JWT token generation, why is it important to use a strong hashing algorithm? A. To make the token generation process faster B. To ensure tokens are unique and cannot be easily forged C. To allow tokens to be easily decrypted by clients D. To reduce the size of the JWT token ANSWER: B # Explanation: Using a strong hashing algorithm ensures that the JWT tokens are secure, unique, and resistant to forgery, thereby maintaining the integrity and authenticity of the tokens. What is the consequence of storing user passwords in plain text within the database? A. Enhanced security through easy retrieval B. Simplified password management for users C. Increased vulnerability to data breaches and unauthorized access D. Improved system performance during authentication ANSWER: C # Explanation: Storing passwords in plain text exposes user credentials to significant security risks, making it easier for attackers to misuse them if a data breach occurs. Why should developers avoid storing user credentials in JWT tokens? A. It simplifies token generation B. It increases the token's security C. It can expose sensitive information if the token is compromised D. It reduces the token's size for faster transmission ANSWER: C # Explanation: Storing user credentials in JWT tokens can expose sensitive information if the token is intercepted or compromised, posing a significant security risk. What should developers ensure when configuring SSL/TLS for HTTPS communication? A. Use outdated SSL/TLS protocols for compatibility B. Obtain and install valid SSL/TLS certificates from a trusted Certificate Authority C. Disable certificate validation on the server D. Allow self-signed certificates for all environments ANSWER: B # Explanation: Developers should obtain and install valid SSL/TLS certificates from trusted Certificate Authorities to ensure secure and trusted HTTPS communication. In a relational database with a normalized schema, how are user roles typically managed? A. By embedding role details directly within the user records B. By storing role information in a separate roles table and linking via foreign keys C. By duplicating role information across multiple user tables D. By storing role names as plain text in the user table without references ANSWER: B # Explanation: In a normalized relational database schema, user roles are managed by storing role information in a separate roles table and linking it to the users table through foreign keys, reducing redundancy and maintaining data integrity. What is the purpose of implementing encrypted storage of secrets in the authentication system? A. To simplify the storage process by using plain text B. To ensure that sensitive information like private keys and shared secrets are protected from unauthorized access C. To allow easy access to secrets by any component of the system D. To reduce the computational overhead during encryption and decryption ANSWER: B # Explanation: Encrypted storage of secrets ensures that sensitive information such as private keys and shared secrets are protected from unauthorized access, enhancing the overall security of the authentication system. Which of the following best describes a "normalized schema" in database design? A. A database design that combines all data into a single table for simplicity B. A schema that organizes data into structured, related tables to reduce redundancy and improve integrity C. A design that embeds all related data within a single document for faster retrieval D. A schema that duplicates data across multiple tables to enhance performance ANSWER: B # Explanation: A normalized schema organizes data into related tables, minimizing redundancy and ensuring data integrity through the use of primary and foreign keys. What is the consequence of using a weak hashing algorithm for password storage? A. It makes password verification faster B. It increases the security of stored passwords C. It makes it easier for attackers to crack hashed passwords D. It reduces the storage space required for passwords ANSWER: C # Explanation: Using a weak hashing algorithm makes it easier for attackers to perform brute-force or dictionary attacks to crack the hashed passwords, compromising user security. What is the primary reason for implementing HTTPS in the authentication flow? A. To increase server performance by reducing encryption overhead B. To ensure data confidentiality and integrity during transmission C. To allow the use of plain text credentials for simplicity D. To enable the use of both HTTP and HTTPS protocols simultaneously ANSWER: B # Explanation: HTTPS ensures that all data transmitted between the client and server is encrypted, maintaining confidentiality and integrity, which is crucial for securely handling user credentials and tokens. What should be included in the payload of a JWT token to support role-based access control? A. User's plain text password B. User's IP address C. User's role and permissions D. User's browser information ANSWER: C # Explanation: Including the user's role and permissions in the JWT payload allows the backend to enforce role-based access control by determining what resources and actions the user is authorized to access. Which of the following is NOT a responsibility of the developer in setting up HTTPS for secure communication? A. Configuring the server with SSL/TLS certificates B. Redirecting all HTTP traffic to HTTPS C. Implementing frontend input validation for user credentials D. Disabling HTTPS to allow faster data transfer over HTTP ANSWER: D # Explanation: Disabling HTTPS compromises the security of data transmission. Developers should ensure HTTPS is enabled and properly configured to protect data confidentiality and integrity. In the context of the provided articles, what is the "black box" referring to? A. A secure storage mechanism for JWT tokens B. An external service or component that processes specific requests, such as user availability C. The frontend application handling user input D. The database storing user credentials ANSWER: B # Explanation: The "black box" refers to an external service or component that handles specific processing tasks, such as determining user availability, which the backend interacts with either synchronously or asynchronously. What is the main difference between the synchronous and asynchronous approaches in accessing the black box? A. Synchronous is suitable for high-traffic systems, while asynchronous is for low-traffic systems B. Synchronous completes the request in real-time, whereas asynchronous queues the task for later processing C. Synchronous requires task queues, while asynchronous does not D. There is no significant difference between the two approaches ANSWER: B # Explanation: The synchronous approach handles requests in real-time within the same transaction, suitable for low-traffic systems. In contrast, the asynchronous approach queues tasks for later processing, which is ideal for high-traffic systems to avoid timeouts and manage load effectively. How does the asynchronous approach help in managing high-traffic applications? A. By processing all requests in real-time to ensure immediate responses B. By queuing tasks and processing them independently, reducing the risk of overwhelming the black box C. By eliminating the need for task queues and worker processes D. By simplifying the overall system architecture ANSWER: B # Explanation: The asynchronous approach queues tasks and processes them independently through worker processes, which helps manage high traffic by preventing the black box from being overwhelmed and reducing the likelihood of timeouts. What is a primary consideration when implementing secure JWT token generation and handling? A. Using short expiration times to minimize token validity B. Including sensitive user information like passwords in the token payload C. Ensuring tokens are signed with strong cryptographic keys and stored securely D. Allowing tokens to be accessible via client-side JavaScript ANSWER: C # Explanation: Secure JWT token generation and handling require that tokens are signed using strong cryptographic keys to prevent tampering and are stored securely to protect against unauthorized access. What should developers do to handle token expiration in the authentication flow? A. Automatically renew tokens without user intervention B. Ignore expired tokens and allow access C. Prompt users to re-authenticate or obtain a new token upon receiving a 401 Unauthorized response D. Extend the token's expiration time indefinitely ANSWER: C # Explanation: When a token expires, developers should prompt users to re-authenticate or obtain a new token to maintain security and ensure that only authenticated users have access.