AES (Advanced Encryption Standard) is a widely used symmetric encryption algorithm. This tool supports two of the most common modes of operation: GCM and CBC.

• AES-GCM (Galois/Counter Mode (GCM)): Provides both encryption and data integrity authentication. It is fast, highly secure, and the preferred choice for modern applications (like TLS 1.3). It requires a unique Initialization Vector (IV) and can handle Additional Authenticated Data (AAD).
• AES-CBC (Cipher Block Chaining (CBC) Mode): A classic and widely used encryption mode. It requires padding the plaintext to match the block size and needs a random Initialization Vector (IV) for security.
• Key (Key): The secret password used for both encryption and decryption. The key length can be 128, 192, or 256 bits. The key must be kept secret, and both parties must use the same key.
• Initialization Vector (IV) (IV): A random number used to ensure that encrypting the same plaintext multiple times with the same key produces different ciphertexts. For GCM, the IV is typically 12 bytes; for CBC, it is 16 bytes.
• Additional Authenticated Data (AAD) (AAD): (GCM only) This data is not encrypted but is included in the authentication calculation. If the AAD is tampered with during transmission, decryption will fail. It is often used to transmit metadata.

All cryptographic operations are performed locally in your browser. Your data is absolutely secure and is never sent to any server.