One-Time Pad Cryptography

This Python project implements a simple cryptographic system using the One-Time Pad (OTP) method. The OTP is a symmetric encryption technique where a random key is used only once to encrypt a message. The key must be as long as the message, making it theoretically unbreakable if used correctly.

Features

• Character to Bits Conversion: Maps characters to their corresponding 5-bit binary representation.
• Bits to Character Conversion: Maps 5-bit binary strings back to their corresponding characters.
• Text to Bits: Converts a given text message to a string of bits.
• Bits to Text: Converts a string of bits back to the original text message.
• Random Key Generation: Generates a random binary key of specified length.
• OTP Encryption/Decryption: Encrypts and decrypts messages using the OTP method.

Functions

text_to_bits(text)

Converts a given text message to a string of bits, removing any characters not in the predefined character set and converting to uppercase.

• Parameters: text (str) - The text message to be converted.
• Returns: (str) - The resulting string of bits.

bits_to_text(bits)

Converts a string of bits back to the original text message by mapping each 5-bit chunk to its corresponding character.

• Parameters: bits (str) - The string of bits to be converted.
• Returns: (str) - The resulting text message.

generate_random_key(length)

Generates a random binary key of the specified length.

• Parameters: length (int) - The length of the key to be generated.
• Returns: (str) - The resulting random key.

otp_encrypt_decrypt(message_bits, key_bits)

Encrypts or decrypts a message using the OTP method by XORing each bit of the message with the corresponding bit of the key.

• Parameters:
  • message_bits (str) - The bits of the message to be encrypted or decrypted.
  • key_bits (str) - The bits of the key.
• Returns: (str) - The resulting encrypted or decrypted bits.