Safe computing

• 1 min read

PII: Personally Identifiable Information

  • Information identifying a user
  • Safe computing revolves around PII: how it’s secured and how it can be exploited

Cookies

  • Session
  • Persistent
  • First-party
  • Third-party

Password Security

  • More complicated passwords = better security

Encryption

  • Converting data into coded format to prevent unauthorized access (only the user can access)
  • Symmetric Encryption: Same key used for encryption and decryption
  • Asymmetric/Public Key Encryption: More secure for internet communications
  • Encryption is used in web security and messaging apps

Phishing

  • Cyber attack where scammers trick users into giving personal info (bank details, passwords, etc.)

Types of Phishing

  • Email Phishing: Pretend to be a big company (Check email domain)
  • Website Spoofing: Attackers create fake versions of popular websites to steal login info
    • Avoid by typing the correct URL
  • Smishing: Hackers send fake text messages pretending to be big companies and urge you to click on a link
    • Prevent by not clicking on links from unknown numbers

Verification

  • Important for safe computing
  • Ensure everything is legit and safe

Homework hack (code)

import random

python
def caesar_cipher(text, shift, mode):
    result = ""
    for char in text:
        if char.isalpha():  # This part of the code only encrypts letters
            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  # this keeps the spaces and position unchanged
    return result

# Here is the code for getting the 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 of places to shift, or type 'random'): ").strip().lower()

# Determine shift value
if shift_input == "random":
    shift = random.randint(1, 25)
    print(f"Random shift value chosen: {shift}")
else:
    shift = int(shift_input)

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

Completed MCQ: