Absolute Zero-Knowledge File Encryption
When dealing with sensitive business documents, proprietary source code, or confidential client files, transferring your data to third-party cloud servers is an unacceptable security risk. Even "secure" cloud encryption services often hold the decryption keys on their own servers, leaving your data vulnerable to data breaches and insider threats. The Secure File Encrypter solves this by performing military-grade cryptographic operations entirely offline.
Built on top of the native HTML5 Web Crypto API, this tool ensures that your file never leaves your browser. There are no server uploads, no temporary cloud storage, and no backend API calls. Everything happens locally on your machine.
How AES-256-GCM Works
When you select a file and enter a password, the tool utilizes the PBKDF2 (Password-Based Key Derivation Function 2) algorithm with a SHA-256 hash. It runs through 100,000 iterations against a cryptographically secure random salt to derive a robust 256-bit encryption key from your password.
This key is then fed into the AES-GCM (Advanced Encryption Standard in Galois/Counter Mode) algorithm. AES-256 is the standard adopted by the U.S. government for classified information, and the GCM mode provides both data confidentiality and authenticity (meaning the file cannot be tampered with without the password). The output is a highly secure .enc file containing the random salt, the Initialization Vector (IV), and your encrypted file data.
Decryption and Recovery
Because this is a strict zero-knowledge architecture, we cannot recover your password if you lose it. The .enc file generated by this tool is statistically impossible to crack via brute force without the exact password used during encryption. To decrypt your file, simply return to this page, drag the .enc file into the drop zone, and enter your original password. The tool will instantly unpack the binary blob, verify the cryptographic signature, and restore your original file locally.
When to Use This Tool
- Emailing Sensitive Documents: Encrypt tax documents or legal contracts before attaching them to insecure email threads.
- Cloud Backup Archiving: Pre-encrypt massive ZIP files before uploading them to Google Drive or Dropbox.
- Source Code Delivery: Send proprietary application builds or `.env` files to clients securely.