About Encrypt File
Encryption and decryption with a password: encrypt a file before it goes somewhere you don't fully control, like a cloud drive, a USB stick that could get lost, or an email to your accountant. Pick the file, choose a password and your browser turns it into an encrypted .cfenc copy. Without the password, the contents can't be read.
The work happens on your device, so neither the file nor the password is sent to us. Under the hood it's AES-256-GCM, with the key derived from your password through 600,000 rounds of PBKDF2-SHA256, which makes guessing slow and expensive. The original name and file type are sealed inside and restored when you decrypt. Forget the password, though, and nobody can recover the file, us included.
How to use Encrypt File
- 1Pick the file
Click Choose a file to encrypt or drop it on the page. Any type works, from PDFs and photos to spreadsheets and archives.
- 2Set a strong password
Type it twice. It needs at least 6 characters, and the strength bar shows how you're doing; longer is better.
- 3Encrypt and download
Click Encrypt and download. Your browser will encrypt the file and save it with .cfenc added, for example tax-return.pdf.cfenc.
- 4Pass the password separately
Store or send the .cfenc file and share the password another way. It opens with Decrypt File on any device.
Why use Cubfile for this
- Stays on your device
Encryption runs in your browser. The file and the password never reach our servers.
- AES-256-GCM with PBKDF2
The same cipher family that secures HTTPS connections, with a key stretched through 600,000 rounds of PBKDF2 to slow down password guessing.
- Tampering is detected
Every piece of the file carries an authentication tag, so a damaged or altered file is reported instead of decrypting to garbage.
- Original name restored
The file name and type are sealed inside, so decrypting gives back report.pdf, not a mystery file.