Token-based authentication (JWT) in IOT Protocols - Mini Project: Build & Apply

Token-based authentication (JWT)

📖 Scenario: You are working on a simple IoT device management system. Each device needs to authenticate itself using a token before it can send data. The system uses JSON Web Tokens (JWT) to verify device identity securely.

🎯 Goal: Build a small program that creates a JWT token for a device, sets a secret key for signing, encodes the token with device info, and finally prints the token string.

📋 What You'll Learn

Create a dictionary called device_info with keys device_id and device_type and exact values 'device123' and 'sensor'

Create a variable called secret_key and set it to the string 'mysecretkey'

Use the jwt.encode() function to create a token from device_info signed with secret_key and assign it to token

Print the token variable to display the JWT token string

💡 Why This Matters

🌍 Real World

IoT devices often use JWT tokens to prove their identity securely to servers before sending data.

💼 Career

Understanding JWT token creation and usage is essential for roles in IoT security, backend development, and DevOps automation.

1

Create device information dictionary

Create a dictionary called device_info with these exact entries: 'device_id': 'device123' and 'device_type': 'sensor'.

IOT Protocols

# Your code here

Need a hint?

Think of device_info as a small card with device details.

2

Set the secret key for signing

Create a variable called secret_key and set it to the string 'mysecretkey'.

IOT Protocols

device_info = {'device_id': 'device123', 'device_type': 'sensor'}
# Your code here

Need a hint?

The secret key is like a password only your system knows.

3

Create the JWT token

Use the jwt.encode() function to create a token from device_info signed with secret_key and assign it to token. Assume jwt is already imported.

IOT Protocols

device_info = {'device_id': 'device123', 'device_type': 'sensor'}
secret_key = 'mysecretkey'
# Your code here

Need a hint?

Use algorithm='HS256' for signing the token.

4

Print the JWT token

Write print(token) to display the JWT token string.

IOT Protocols

token = jwt.encode(device_info, secret_key, algorithm='HS256')
# Your code here

Need a hint?

The printed token should start with eyJ, which is common for JWT tokens.