Here is a complete, single-file solution for a self-decrypting web page.

The architecture relies on a Python script to handle the heavy lifting of encryption (using standard AES-GCM via Python’s cryptography library) and a standalone HTML file that embeds CryptoJS and a lightweight decryption script. When opened in any browser, the user sees a secure “front door” password prompt. If correct, the ciphertext is decrypted client-side and dynamically replaces the DOM.