Open a sealed archive
Most people do not need this page. If the file you were sent is called Open me, just double-click it.
The file that Departed sends opens itself. Save it, double-click it, and it asks for the passphrase. This page is here for the case where you have only the encrypted part, or where the file will not open for some reason.
Either way the work happens in your own browser. Nothing is uploaded, the passphrase is not sent anywhere, and nothing here is recorded or counted. You can disconnect from the internet first and it will still work.
If you would rather not use this page
You do not have to trust it, and you do not need it. The file is an ordinary encrypted file, made the way OpenSSL makes them. Any Mac or Linux computer will open it with one command.
openssl enc -d -aes-256-cbc -pbkdf2 -iter 600000 -md sha256 \
-in departed-sealed.enc -out inside.zipIt asks for the passphrase, and what comes out is a normal zip file that any computer can open. On Windows the same command works inside Git Bash or the Windows Subsystem for Linux.
If the passphrase does not work
Check for a typed letter that should be a number, or a missing dash. The passphrase is all lower case, and it never contains the letters l or o, so those are almost certainly a one and a zero. If it still refuses, the file may have been damaged in transit, and there is nothing this page can do about that.
What this file is
Somebody set up a program called Departed to send it to you if they stopped answering its emails. Nobody read it on the way, and nobody but you has the passphrase. It was not stored anywhere by the program, and it cannot be recovered if it is lost.