Concept & Knowledge Hub
AES 256 Cryptography: Galois Counter Mode Encryption
AES 256 GCM is a symmetric key cryptographic cipher utilized by the US government to protect classified, Top Secret data. It ensures both absolute confidentiality and data authenticity.
Pasting sensitive passwords into a cloud encryptor is a catastrophic security failure. This utility utilizes the browser's native `window.crypto.subtle` API to perform military grade encryption entirely client side.
Core Architecture & Mathematical Formula
Ciphertext = AES_GCM_Encrypt(Plaintext, Key, Initialization Vector)
The algorithm mathematically scrambles the text using a 256 bit key. It also attaches an authentication tag, ensuring that if even a single byte of the encrypted file is altered by a hacker, the decryption will fail.
Best Practices & Essential Guidelines
- Never Lose the Key: AES 256 is mathematically unbreakable. If you encrypt a file and forget the password, there is no 'Reset Password' button. The data is permanently lost to the void.
- Understand Symmetric vs Asymmetric: AES is 'Symmetric', meaning the exact same password is used to both lock and unlock the file. If you send the file to a friend, you must also securely transmit the password via a separate channel.
- The Initialization Vector (IV) is Critical: The IV ensures that encrypting the exact same message twice produces two completely different encrypted strings. Never reuse an IV with the same key.
Frequently Asked Questions (FAQ)
Can a quantum computer break AES 256?
Currently, no. While quantum computers theoretically threaten asymmetric cryptography (like RSA), symmetric ciphers with 256 bit keys (like AES) are considered highly resistant to quantum algorithms like Grover's.
What does Base64 output mean?
Raw encrypted data is just a chaotic stream of binary 1s and 0s. Base64 encodes that binary into standard printable characters so you can easily copy and paste the encrypted text.
Is the browser's Web Crypto API actually safe?
Yes. The Web Crypto API is an incredibly secure, native implementation. The encryption happens directly on your CPU hardware; the JavaScript code simply acts as the trigger.