Overview

  • login logout system

Step 1: Functional Requirements:

  • User Registration: Allow users to create an account by providing their email address, username, and password.
  • User Login: Authenticate users based on their credentials and grant access to the system.
  • User Logout: Allow users to securely log out of the system, terminating their session.
  • Password Reset: Provide a mechanism for users to reset their forgotten passwords.

Step 2: Non-Functional Requirements:

  • Security: Implement secure authentication mechanisms to protect user data and prevent unauthorized access.
  • Scalability: Design the system to handle a large number of concurrent users.
  • Availability: Ensure high availability and uptime to provide uninterrupted service.
  • Performance: Optimize system performance to handle login/logout requests efficiently.
  • Usability: Create a user-friendly interface for a seamless login/logout experience.

Step 3: Back-of-the-Envelope Math:

Let’s assume the following approximate numbers to perform some calculations:

  • Daily Active Users (DAU): 100,000
  • Concurrent Users (CU): 10,000
  • Average Login/Logout Requests per User: 2
  • Calculating the login/logout requests per day:
  • Total Login/Logout Requests per Day = DAU * Average Login/Logout Requests per User

  • Total Login/Logout Requests per Day = 100,000 * 2 = 200,000 requests

  • Calculating the peak login/logout requests per second:
  • Peak Requests per Second = Total Login/Logout Requests per Day / (24 hours * 60 minutes * 60 seconds)
  • Peak Requests per Second = 200,000 / (24 * 60 * 60) ≈ 2.31 requests per second

Design and detail

+—————–+ +——————-+ +——————-+ | | Login | | Authenticate | | | User Interface+————>| Authentication |<—————>| User Database | | | | Service | (Hashing) | | +—————–+ +——————-+ +——————-+ | v +——————-+ | | | Session Management| | | +——————-+ | v +——————-+ | | | Security | | | +——————-+

+———————+ | User Interface | +———————+ | | Requests V +———————+ | Load Balancer | +———————+ | | Requests V +———————+ | Authentication Service | +———————+ | | Queries V +———————+ | User Database | +———————+ | | Session Tokens V +———————+ | Session Management | +———————+ | | Logs and Monitoring V +———————+ | Security Components | +———————+

  1. User Interface:
    • Provides a login form where users enter their credentials (username and password) to initiate the login process.
    • Displays a logout functionality or button for users to terminate their session.
  2. Authentication Service:
    • Receives the login request from the User Interface and extracts the provided username and password.
    • Retrieves the corresponding user record from the User Database based on the provided username.
    • Extracts the stored salt associated with the user’s account from the user record.
    • Combines the entered password with the salt to create a salted password.
    • Hashes the salted password using a strong hashing algorithm, such as bcrypt or Argon2, to generate the password hash.
    • Compares the generated password hash with the stored password hash in the user record for verification.
    • If the verification succeeds, generates a session token for the authenticated user.
    • Associates the session token with the user’s account in the Session Management component.
    • Sends the session token back to the User Interface for future requests.
  3. User Database:
    • Stores user information, including usernames and hashed passwords.
    • The password is hashed using a secure hashing algorithm, such as bcrypt or Argon2, before storing it in the database.
    • Each user record also includes a unique salt value, which is randomly generated during the account creation process.
  4. Session Management:
    • Tracks active user sessions and manages session tokens.
    • Associates session tokens with user accounts to keep track of authenticated users.
    • Enforces session timeouts to automatically log out users after a specified period of inactivity.
  5. Security:
    • Implements a strong hashing algorithm, such as bcrypt or Argon2, for password hashing.
    • Generates a random salt for each user and combines it with their password during the hashing process.
    • The salted password is then hashed, and the resulting hash is stored in the User Database.
    • This ensures that even if multiple users have the same password, their stored hashes will be unique due to the different salts used.
  6. Logging and Monitoring:
    • Captures login and logout events, including timestamps and user information, for auditing purposes.
    • Monitors system performance, tracks login/logout success rates, and identifies any anomalies.
    • Logs security-related events, such as failed login attempts or suspicious activity, for security analysis and investigation.