Introduction of the Project
Do you like cryptography? Encryption – decryption techniques make you feel worth digging deeper into? If yes, today, we will implement the Caesar Cipher to encrypt and decrypt the message along with some GUI using the Tkinter module. To encode and decode messages using the Tkinter module, let us know a bit about the Caesar cipher before implementing it.
Caesar cipher is based on shifting the alphabets by a fixed number known as the key to get an encrypted or, say, encoded message and reverse it to get decrypted or decoded message. Some terminologies:
- Original message = PlainText = Decrypted/ Decoded message
- Cyphertext = Encrypted/Encoded message
- A numeric key is used to convert from first to second and vice versa.
Requirements
1. Python 3.9 interpreter, you can use VSCode or any python IDE.
NOTE: A certain file needs to be preinstalled for the code’s smooth running, due to which IDLE or IDE is a preferred choice.
2. Pre-installed Tkinter module to create GUI.
Steps To Encode And Decode Messages With Python Using Tkinter Module
Step 1: Do the following as per your Operating System:
Windows: Open Command Prompt and type
macOS: Open Terminal and type
pip3 install tk
Installing Tkinter
Step 2: Paste the below piece of code in your editor/IDE.
Source Code
# Import the module for GUI
import tkinter as tk
# Initialising the font type and size
FONT = ("timesnewroman", 25, "bold")
class CaesarCypherGUI:
def __init__(self, master):
# Title for the window
master.title("Caesar Cypher GUI")
# String type for plaintext and cyphertext
self.plaintext = tk.StringVar(master, value="")
self.cyphertext = tk.StringVar(master, value="")
# Integer value for the key
self.key = tk.IntVar(master)
# Plaintext GUI and controls
self.plain_label = tk.Label(master, text="Plaintext", fg="green", font=FONT).grid(row=0, column=0)
self.plain_entry = tk.Entry(master, textvariable=self.plaintext, width=40, font=FONT)
self.plain_entry.grid(row=0, column=1, padx=20)
# Button constructs a button
self.encrypt_button = tk.Button(master, text="Encrypt", command=lambda: self.encrypt_callback(), font=FONT).grid(row=0, column=2)
self.plain_clear = tk.Button(master, text="Clear", command=lambda: self.clear('Plain'), font=FONT).grid(row=0, column=3)
# Key controls
self.key_label = tk.Label(master, text="Key", font=FONT).grid(row=1, column=0)
self.key_entry = tk.Entry(master, textvariable=self.key, width=10, font=FONT).grid(row=1, column=1, sticky=tk.W, padx=20)
# Cyphertext controls
self.cypher_label = tk.Label(master, text="Cyphertext", fg="red", font=FONT).grid(row=2, column=0)
self.cypher_entry = tk.Entry(master, textvariable=self.cyphertext, width=40, font=FONT)
self.cypher_entry.grid(row=2, column=1, padx=20)
self.decrypt_button = tk.Button(master, text="Decrypt", command=lambda: self.decrypt_callback(), font=FONT).grid(row=2, column=2)
self.cypher_clear = tk.Button(master, text="Clear", command=lambda: self.clear('Cypher'), font=FONT).grid(row=2, column=3)
# Defination of clear function
def clear(self, str_val):
if str_val == 'cypher':
self.cypher_entry.delete(0, 'end')
elif str_val == 'plain':
self.plain_entry.delete(0, 'end')
# Defination of key function
def get_key(self):
try:
key_val = self.key.get()
return key_val
except tk.TclError:
pass
# Encryption method
def encrypt_callback(self):
key = self.get_key()
cyphertext = encrypt(self.plain_entry.get(), key)
self.cypher_entry.delete(0, tk.END)
self.cypher_entry.insert(0, cyphertext)
# Decryption method
def decrypt_callback(self):
key = self.get_key()
plaintext = decrypt(self.cypher_entry.get(), key)
self.plain_entry.delete(0, tk.END)
self.plain_entry.insert(0, plaintext)
# Encryption formula of Caeser cipher
def encrypt(plaintext, key):
cyphertext = ""
for char in plaintext.upper():
if char.isalpha():
cyphertext += chr((ord(char) + key - 65) % 26 + 65)
else:
cyphertext += char
return cyphertext
# Decryption formula of Caser cipher
def decrypt(cyphertext, key):
plaintext = ""
for char in cyphertext.upper():
if char.isalpha():
plaintext += chr((ord(char) - key - 65) % 26 + 65)
else:
plaintext += char
return plaintext
# Run the program
if __name__ == "__main__":
root = tk.Tk()
caesar = CaesarCypherGUI(root)
root.mainloop()
Explanation Of The Code
To begin with, we have imported the Tkinter module.
1. Then, we have initialized the font type and size of the text in the window.
2. After that, we used the title function to give the window’s title.
3. Then, we constructed a sting and integer variable for the cryptographical text and key.
4. Then, we have used the label, Entry, & button function for the control of the GUI of Plaintext, key, and ciphertext.
5. Then, we have written the definition for the clear and key function to clear the textbox and get the key.
6. After this, we have implemented the formula of encryption and decryption of Caesar cipher using python.
7. At last, we are running the application.
Output
The below snip shows the window of encoding decoding GUI that we have implemented using the Tkinter module.
1. Encryption using Caeser cipher and Tkinter module in python
2. Decryption using Caeser cipher and Tkinter module in python
Conclusion
Using the Tkinter module and some basic python functions, we have implemented cryptography for encoding and decoding messages using caesar cipher along with its GUI.