What is AES-256-GCM?
The Advanced Encryption Standard (AES) is a symmetric block cipher. The "256" refers to the 256-bit key size, providing military-grade security computationally impenetrable against brute-force attacks.
GCM (Galois/Counter Mode) provides Authenticated Encryption. It not only encrypts data but generates an authentication tag. If a malicious actor alters a single bit, decryption fails entirely.
How this tool works locally
This tool utilizes the native window.crypto.subtle interface.
1
Key Derivation (PBKDF2)
Password stretched with 100,000 iterations to build 256-bit key.
2
Initialization Vector (IV)
Random 12-byte IV ensures unique ciphertexts per encryption.
3
AES-GCM Encryption
Plaintext locked, producing ciphertext and auth tag.
4
Base64 Packaging
Salt, IV, and Ciphertext concatenated and encoded.