AES Encryption/Decryption
Based on Web Crypto API and PBKDF2 key derivation, using CBC mode with a random IV for every encryption and a selectable 128/256-bit key length. Runs purely in browser without server upload.
FAQ
Is AES encryption secure?
AES (Advanced Encryption Standard) is a symmetric encryption algorithm certified by the U.S. National Institute of Standards and Technology (NIST), widely adopted by governments and enterprises worldwide. Both AES-128 and AES-256 are considered secure when used correctly (with random IV and proper key management). AES-256 provides higher security margins, but AES-128 is also sufficient until the quantum computing era arrives.
What's the difference between CBC and ECB modes?
CBC (Cipher Block Chaining) mode XORs each plaintext block with the previous ciphertext block before encryption, so identical plaintext blocks produce different ciphertext, providing better security but requiring a random IV. ECB (Electronic Codebook) mode encrypts each plaintext block independently, so identical plaintext blocks produce identical ciphertext, potentially leaking data patterns. ECB is not recommended for encrypting multi-block data, and this tool does not offer it.
Which is better, AES-128 or AES-256?
AES-256 uses longer keys (256 bits vs 128 bits), providing higher security margins against brute-force attacks. However, AES-256 has slightly higher computational overhead than AES-128. For most applications, AES-128 is already sufficiently secure. If you need to protect highly sensitive data or plan for long-term security requirements, choose AES-256.
Output format explanation
Encryption output is a Base64 encoded string in the format: PBKDF2 Salt (16 bytes) + IV (16 bytes) + Ciphertext. To decrypt, simply input the same Base64 string.