Use the website

Address: getcadenas.com

Encrypt a file

1. Drop a file, several files or a whole folder. Several files or a folder are bundled into a .zip archive before being encrypted.
2. Enter a password, or click Generate a passphrase to get one made of 5 random words.
3. Download the result: report.pdf becomes report.pdf.cadenas.

Decrypt a file

Drop the .cadenas or .age file, type the password, download the original file. cadenas recognizes on its own whether a file needs encrypting or decrypting.

If the password is wrong, or if the file was modified or truncated, cadenas says so and produces no file.

Received an encrypted file?

The page getcadenas.com/#decrypt does only one thing: open an encrypted file. It is the address to give your recipient (see Send an encrypted file).

Offline and installation

After a first visit, the website works offline. It can also be installed like an app: browser menu, then "Install cadenas" or "Add to Home Screen".

Once installed on Chrome or Edge, cadenas appears in "Open with" for .cadenas and .age files.

Large files

There is no fixed limit: files are processed in 64 KiB chunks. Results larger than 256 MiB are never kept in memory: Chrome and Edge write them straight to disk, Firefox and Safari download them as they go.

Language

The website is in English or French, depending on the browser language.

Check that nothing is sent

The page forbids itself any network connection, through its Content Security Policy (connect-src 'none'). To see it for yourself:

• open the browser's developer tools, Network tab, then encrypt a file: no request goes anywhere but the website's address, which only loads its own scripts;
• or turn off the Internet after the first visit: the website keeps working.

Automated tests check this restriction in Chromium, Firefox and WebKit on every code change. The protections are detailed in the assurance case.