AES-256-GCM Encryption Tool
Securely encrypt and decrypt text using military-grade AES-256-GCM encryption. Works reliably on all browsers.
🔒 Your Data is Fully Protected
Your data is never stored. All encryption and decryption is processed securely and immediately discarded—no data is saved to any database or file system. We use military-grade AES-256-GCM encryption with PBKDF2 key derivation (100,000 iterations) for maximum security. This tool works reliably across all browsers.
Remember this password - you'll need it to decrypt the data
About AES-256-GCM Encryption
AES-256-GCM (Advanced Encryption Standard with Galois/Counter Mode) is the gold standard for authenticated encryption. It's the encryption mode used in TLS 1.3 (securing all HTTPS connections), SSH, IPsec, and countless other security protocols. GCM is an AEAD (Authenticated Encryption with Associated Data) cipher, meaning it provides both confidentiality and integrity in a single operation.
Technical Specifications
Encryption Algorithm
AES-256 (Advanced Encryption Standard with 256-bit key) in GCM (Galois/Counter Mode). This is approved by NIST and NSA for protecting classified information up to TOP SECRET level.
Key Derivation
PBKDF2-HMAC-SHA256 with 100,000 iterations and a random 128-bit salt. This stretches your password into a cryptographically strong 256-bit key while resisting brute-force attacks.
Initialization Vector
A cryptographically random 96-bit (12-byte) IV is generated for each encryption. This ensures identical plaintexts produce different ciphertexts (semantic security) and is the NIST-recommended IV size for GCM.
Authentication Tag
GCM produces a 128-bit authentication tag that verifies data integrity. Any modification to the ciphertext, IV, or salt will cause decryption to fail, protecting against tampering.
How GCM Mode Works
1. Counter Mode Encryption: GCM encrypts a counter value (starting from the IV) with AES, then XORs the result with your plaintext. This turns the block cipher into a stream cipher, requiring no padding.
2. Galois Field Authentication: Simultaneously, GCM computes a polynomial hash (GHASH) over the ciphertext using Galois field multiplication. This produces the authentication tag with minimal overhead.
3. Single-Pass Operation: Both encryption and authentication happen in a single pass through the data, making GCM extremely efficient—often hardware-accelerated via AES-NI and PCLMULQDQ instructions.
Security Recommendations
✓ Best Practices
- • Use passwords with 16+ characters
- • Use the built-in password generator
- • Store passwords in a password manager
- • Never reuse passwords across encryptions
- • Keep encrypted data and passwords separate
✗ Common Mistakes
- • Using short or dictionary-word passwords
- • Sharing passwords over insecure channels
- • Storing passwords with encrypted data
- • Forgetting passwords (unrecoverable!)
- • Assuming encryption hides data length
Comparison with Other Modes
| Feature | AES-GCM | CTR+HMAC | CBC+HMAC |
|---|---|---|---|
| Authentication | Built-in (AEAD) | Separate HMAC | Separate HMAC |
| Speed | Fastest (single pass) | Fast (two passes) | Moderate (two passes) |
| Key Management | Single key | Dual keys (separated) | Dual keys (separated) |
| Padding | Not required | Not required | Required (PKCS7) |
| Best For | General use, TLS | Key separation needs | Legacy compatibility |
Implementation Details
This tool uses industry-standard Node.js crypto module for all cryptographic operations, ensuring consistent and reliable encryption across all browsers. Your data is never stored—all encryption and decryption operations are processed in memory and immediately discarded. No data is saved to any database, file system, or logs. Your privacy and security are our top priority.