File Encryptor
What this tool does
It locks a file so only someone with your passphrase can open it. The file is encrypted with AES-256-GCM — the same standard used to protect data across the web — and the result is a compact .kitenc file you can store or share safely. That .kitenc file is opened by this tool: to unlock it, come back here, switch to Decrypt, and enter the passphrase (it is not meant to open in 7-Zip, WinRAR, or GPG).
How the encryption works
Your passphrase is turned into a 256-bit key using PBKDF2 with 600,000 SHA-256 iterations (the current OWASP recommendation) and a random salt, which makes brute-force guessing slow. A fresh random value is used for every file, and AES-GCM also verifies integrity, so a tampered or corrupted file is detected on decryption rather than silently returning wrong data.
Private by design
Everything happens in your browser with the built-in Web Crypto API — the file and your passphrase are never uploaded. Because there is no server and no backdoor, there is also no way to recover a lost passphrase, so keep it somewhere safe. This tool is great for protecting files before emailing or backing them up; for full-disk or long-term archival needs, use a dedicated, audited encryption tool.
Frequently asked questions
Is my file or passphrase uploaded?
No. Encryption and decryption happen locally with your browser’s Web Crypto API using AES-256-GCM, so neither the file nor your passphrase ever leaves your device.
What happens if I forget the passphrase?
The file cannot be recovered. There is no backdoor or reset — that is what makes the encryption strong — so store your passphrase somewhere safe.
How is the key protected?
Your passphrase is stretched into a 256-bit key with PBKDF2 (600,000 SHA-256 iterations, per current OWASP guidance) and a random salt, then used with AES-GCM, which also detects tampering. A longer, stronger passphrase means stronger protection.
Can I open the file on another computer?
Yes — download the encrypted .kitenc file, then on any device open this same tool, switch to Decrypt, choose the file, and enter the passphrase. The .kitenc format is specific to this tool: it opens here, not in 7-Zip, WinRAR, or other software.