This HTML code creates a simple web-based application for encrypting and decrypting messages using a substitution cipher, named the "GERMANIKUS Cipher". The cipher works by generating a unique alphabet based on the keyword "GERMANIKUS" and then mapping letters to their numerical positions for encryption, and vice-versa for decryption.
Here's a brief overview of its functionality:
- Cipher Alphabet Generation: A unique cipher alphabet is generated by first including all unique letters from the keyword "GERMANIKUS" in order, followed by the remaining letters of the English alphabet (A-Z) in their usual order.
- Encryption: When a user inputs text and clicks "Encrypt," each letter in the input (case-insensitive) is replaced by its 2-digit numerical position (1-indexed) in the generated cipher alphabet. Non-alphabetic characters are retained as they are.
- Decryption: When a user inputs a sequence of numbers (separated by spaces or commas) and clicks "Decrypt," the numbers are converted back to letters based on their 1-indexed position in the cipher alphabet. Non-numeric parts are retained.
- User Interface: The tool provides a text area for input, and buttons for encryption and decryption. The output is displayed in a designated area on the webpage.