Back-End Development Back-End Security and Authentication

Question 1

What is JWT and what is it commonly used for in back-end applications?

Accepted Answer

JSON Web Token — used for stateless authentication and authorization

Answer

JavaScript Web Template — used for front-end rendering

Answer

Java Web Transfer — used for file uploads

Answer

JavaScript Worker Thread — used for background processing

Question 2

What is the purpose of bcrypt when handling passwords in a back-end application?

Accepted Answer

To hash passwords with a salt before storing them in the database

Answer

To encrypt passwords for transmission over the network

Answer

To generate one-time passwords for two-factor authentication

Answer

To validate password complexity rules

Question 3

What does SQL injection attack involve?

Accepted Answer

Inserting malicious SQL code into input fields to manipulate database queries

Answer

Injecting malicious JavaScript into web pages

Answer

Overloading the server with SQL queries

Answer

Stealing SQL credentials from server configuration files

Question 4

What is the best way to prevent SQL injection in a back-end application?

Accepted Answer

Using parameterized queries or prepared statements

Answer

Encrypting all database connections

Answer

Validating input length only

Answer

Storing queries in environment variables

Question 5

What is the difference between authentication and authorization?

Accepted Answer

Authentication verifies identity; authorization determines permissions

Answer

Authentication checks what you can do; authorization checks who you are

Answer

They are the same concept with different names

Answer

Authorization happens before authentication

Question 6

What is OAuth 2.0 used for in back-end development?

Accepted Answer

Delegated authorization allowing third-party apps to access resources without sharing passwords

Answer

Encrypting database connections

Answer

Generating cryptographic keys for JWT

Answer

Two-factor authentication via SMS