This Python code implements a Caesar Cipher, which is a simple encryption technique. It works by shifting each letter in a message by a certain number of positions down the alphabet.
The code is divided into three functions:
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encrypt(message, key): This function takes a message and a key as input. It iterates over each character in the message and checks if it's an alphabetical character (a-z, A-Z).-
If it is alphabetical, it performs the shift based on the key value.
- It converts the character to its corresponding ASCII code.
- It adds the key value to the ASCII code.
- It takes the modulo 26 of the sum to handle overflow (resulting in a value between 0-25).
- It converts the new ASCII code back to a character.
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If the character is not alphabetical, it remains unchanged.
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decrypt(encrypted_message, key): This function works similarly to the encryption function, but it subtracts the key value from the ASCII code to shift the letters back to their original positions. -
main(): This function is the entry point of the program. It prompts the user for a message and a key, encrypts the message using theencryptfunction, decrypts the encrypted message using thedecryptfunction, and then prints both the original and encrypted messages.
This is a basic Caesar Cipher and has limitations:
- It only encrypts alphabetical characters (a-z, A-Z).
- It's not a secure encryption method, as someone can easily crack the code by trying different key values (brute-force attack).
