Big Idea 5: Safe Computing

[Im2008]

Safe Computing Hacks & Homework Hacks

Popcorn Hack 1: Cookies

1. Open Developer Tools using fn + F12 or Ctrl + Shift + I.
2. Navigate to the Application tab.
3. Click on Cookies under the "Storage" section.
4. Select a website from the list to see its cookies.
5. Identify the following details for a cookie:
   • Name: (E.g., session_id)
   • Value: (Random string assigned by the website)
   • Expiration Date: (E.g., 2025-12-31T23:59:59.000Z)
   • Category:
     • If it disappears after closing the browser → Session Cookie
     • If it stays beyond closing the browser → Persistent Cookie
     • If from the same website you're visiting → First-Party Cookie
     • If from another domain (advertising, tracking) → Third-Party Cookie

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Popcorn Hack 2: CAPTCHA

To test CAPTCHA:

1. Visit a website that uses CAPTCHA (Google reCAPTCHA demo).
2. Observe how it prevents bots from entering the website.
3. Try refreshing the page to see different CAPTCHA challenges.

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Homework Hack 1: MCQ

1. Which of the following is an example of PII (Personally Identifiable Information)?

• a) A username like "Gamer_123"
• b) An IP address
• c) A Social Security Number
• d) A device’s battery percentage

Answer: c) A Social Security Number

2. Which type of cookie remains stored even after closing the browser?

• a) Session Cookie
• b) Persistent Cookie
• c) First-Party Cookie
• d) Third-Party Cookie

Answer: b) Persistent Cookie

3. What is the key difference between symmetric and asymmetric encryption?

• a) Symmetric encryption uses different keys for encryption and decryption
• b) Asymmetric encryption uses the same key for encryption and decryption
• c) Symmetric encryption uses the same key, while asymmetric encryption uses a public-private key pair
• d) None of the above

Answer: c) Symmetric encryption uses the same key, while asymmetric encryption uses a public-private key pair

4. How can you identify a phishing email?

• a) It comes from an unknown sender and has suspicious links
• b) The email asks for personal details like passwords
• c) It contains urgent messages or threats
• d) All of the above

Answer: d) All of the above

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Homework Hack 2: Modified Caesar Cipher Code

Here’s the modified Python code that allows for a random shift value:

import random

def caesar_cipher(text, shift, mode):
    if shift == "random":  # If user inputs "random", pick a random number
        shift = random.randint(1, 25)
        print(f"Random shift value used: {shift}")  # Inform the user of the shift

    result = ""
    for char in text:
        if char.isalpha():
            shift_amount = shift if mode == "encrypt" else -shift
            new_char = chr(((ord(char.lower()) - 97 + shift_amount) % 26) + 97)
            result += new_char.upper() if char.isupper() else new_char
        else:
            result += char  # Keeps spaces and non-alphabet characters unchanged
    return result

# Getting user input
mode = input("Do you want to encrypt or decrypt? ").strip().lower()
message = input("Enter your message: ")
shift_input = input("Enter shift value (number between 1 and 25, or type 'random'): ")

# Convert shift input to integer if it's not "random"
shift_value = shift_input if shift_input.lower() == "random" else int(shift_input)

# Perform encryption/decryption
output = caesar_cipher(message, shift_value, mode)
print(f"Result: {output}")