About

This utility provides a zero-trust, client-side implementation of the AES (Advanced Encryption Standard) algorithm. Unlike server-side tools, this application executes all cryptographic operations locally within your browser's runtime environment using the native window.crypto.subtle API. Your private keys and plaintext data never traverse a network.

We implement PBKDF2 (Password-Based Key Derivation Function 2) with 100,000 iterations of SHA-256 hashing to derive a cryptographically strong 256-bit key from your passphrase. This mitigates brute-force attacks and rainbow table lookups. The tool supports authenticated encryption via AES-GCM (Galois/Counter Mode) and standard AES-CBC (Cipher Block Chaining), ensuring both confidentiality and integrity.

Warning: While the mathematics are sound (P ≠ NP), security depends on the entropy of your password. A weak password renders strong encryption useless. This tool allows for file encryption, text obfuscation, and steganographic embedding.

Formulas

The core encryption process for a block cipher mode like CBC can be described as:

{

C₀ = IVC_i = E_k(P_i &xor; C_i-1)

Where C is the ciphertext block, P is the plaintext block, k is the secret key, and &xor; represents the XOR operation.

Key Derivation (PBKDF2):

DK = PBKDF2(PRF, Password, Salt, c, dkLen)

The entropy H of a password of length L with a character set size N is approximated by:

H ≈ L × log₂(N)

Reference Data

Standard	Block Size	Key Length	Rounds	Quantum Resistance	Use Case
AES-128	128-bit	128-bit	10	Low	Mobile / Legacy
AES-192	128-bit	192-bit	12	Medium	Govt (Secret)
AES-256	128-bit	256-bit	14	High	Govt (Top Secret)
AES-GCM	Stream	Variable	N/A	High	TLS 1.3 / VPN
PBKDF2	N/A	Derived	100k+	N/A	Key Stretching
RSA-2048	N/A	2048-bit	N/A	Vulnerable	Key Exchange
SHA-256	512-bit	256-bit	64	High	Hashing / Integrity

Frequently Asked Questions

No. This tool utilizes the Web Crypto API, which runs entirely in your local JavaScript environment. No network requests are made to send your data or keys to any server.

AES-CBC (Cipher Block Chaining) requires padding and is susceptible to padding oracle attacks if not handled correctly. AES-GCM (Galois/Counter Mode) is an authenticated encryption mode that provides both confidentiality and data integrity without padding, making it generally faster and more secure for modern applications.

This is a security feature. We generate a random 16-byte Salt and a random Initialization Vector (IV) for every encryption operation. This ensures semantic security; an attacker cannot tell if two ciphertexts hold the same message.

Your data is mathematically unrecoverable. AES-256 is currently unbreakable by brute force with existing computing power. Without the key derived from your exact password, the data is indistinguishable from random noise.

Files are read into memory as an ArrayBuffer, encrypted in chunks, and then re-assembled into a Blob for download. Be aware of your device's RAM limits when encrypting very large files (e.g., >1GB) in the browser.