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Ubify Security & Compliance Operations
CYBERSECURITY & PRIVACY AUDITORS
About This Tool
This cryptographic utility performs symmetric authenticated encryption and decryption using the native browser Web Cryptography API (`window.crypto.subtle`). It protects confidential text messages using the Advanced Encryption Standard (AES) operating in Galois/Counter Mode (GCM) with 256-bit keys.
### Cryptographic Specifications & Execution Pipeline - **Key Derivation:** The user's passphrase is encoded into bytes and hashed using SHA-256 (`window.crypto.subtle.digest('SHA-256', keyBytes)`), yielding an exact 256-bit raw cryptographic key. - **Cipher Mode:** AES-GCM (`name: 'AES-GCM'`) provides both confidentiality and built-in cryptographic integrity authentication (a 128-bit authentication tag), preventing undetected ciphertext tampering or bit-flipping attacks. - **Initialization Vector (IV):** During encryption, a cryptographically secure 12-byte (96-bit) random IV is generated via `window.crypto.getRandomValues(new Uint8Array(12))`. - **Payload Packaging:** The 12-byte IV is prepended to the ciphertext and authentication tag. The combined binary buffer is encoded into a portable Base64 string for transmission. - **Decryption Protocol:** During decryption, the Base64 string is decoded into bytes. The first 12 bytes are extracted as the IV, and the remaining bytes are authenticated and decrypted with the derived key. If the key or ciphertext has been altered, decryption fails with an authentication error.
### Concrete Encryption Example 1. **Plaintext:** `Project launch date: 2026-11-15` 2. **Secret Key:** `StagingPass#2026` 3. **Encryption Result:** The tool derives a 256-bit key from the passphrase, generates a fresh 12-byte IV, executes AES-GCM encryption, and outputs a Base64 payload (such as `u1r9X...aP8=`). 4. **Decryption Verification:** Pasting the Base64 output into Decrypt mode with the matching passphrase reconstructs the exact original plaintext string.
### In-Browser Cryptographic Security Note All encryption and decryption routines execute exclusively in your browser's local memory via native Web Crypto API assembly bindings. Secret keys, plaintexts, and ciphertexts never leave your device and are never sent across any network.
How to Use
- 1
Select the operation mode: Encrypt or Decrypt.
- 2
Enter your secret passphrase into the Secret Key field.
- 3
Enter or paste your text (plaintext for encryption, Base64 ciphertext for decryption) into the input box.
- 4
Click Process to execute the AES-GCM operation and copy the resulting string.
Frequently Asked Questions
Why does AES-GCM encryption produce different Base64 outputs for the same text and key?
Every encryption operation generates a unique, cryptographically random 12-byte Initialization Vector (IV). Even with the same text and password, the ciphertext changes on every run to prevent pattern analysis.
What happens if an incorrect key is entered during decryption?
Because AES-GCM is an authenticated cipher mode, the operation will fail cryptographic integrity verification and produce an error rather than returning corrupted plaintext.
Are my passwords or encrypted messages sent to an external server?
No. All key derivation and AES operations occur 100% locally in your browser memory using the native Web Cryptography API.