🔓 Decrypt Data with HMAC Verification

Proper decryption with authentication verification

⚠️ Important: HMAC cannot be "decrypted" - it's a one-way hash for authentication. This tool shows how to decrypt AES-encrypted data while verifying its HMAC signature.

🔒 Production Requirements: This demo requires HTTPS to work in production (crypto.subtle API requirement).

1. Encrypt Data

2. Decrypt & Verify

3. Manual Input

Step 1: Create Encrypted Data with HMAC

First, let's encrypt some data and generate its HMAC for authentication:

Data to Encrypt: Encryption Key: HMAC Key (for authentication):

Step 2: Decrypt Data with HMAC Verification

Now decrypt the data while verifying its authenticity:

Verify HMAC to ensure data integrity

If HMAC is valid, decrypt the data

Display the original plaintext

Step 3: Manual Decryption (Paste Your Own Data)

If you have encrypted data from another source:

Encrypted Data (Base64): IV (Initialization Vector): HMAC Hash: Encryption Key: HMAC Key:

Understanding the Process

Encryption Process:

Generate random IV (Initialization Vector)
Encrypt data using AES-CBC + key + IV
Generate HMAC of (encrypted_data + IV) using HMAC key
Store: encrypted_data, IV, HMAC
                

Decryption Process:

Calculate HMAC of (encrypted_data + IV) using HMAC key
Compare with stored HMAC - if different, data is tampered!
If HMAC matches, decrypt using AES-CBC + key + IV
Return original plaintext
                