How to Encrypt a File with a Password
Encryption turns your data into unreadable bytes that only the right password can restore. It is useful before you email a document, store it in a cloud folder or keep it on a USB stick.
Steps
- Choose a strong password. Use a long random password or passphrase. The key is made from it, so a weak password is the weak point.
- Lock the file. Drop the file in the encryption tool, enter the password twice and download the file ending in .tzenc.
- Send the file and the password separately. Share the password in a different way, for example by phone or in a messaging app, not in the same email.
- Unlock it again. The other person opens the same tool, drops the .tzenc file and enters the password.
Good to know
The tool uses AES-256-GCM with a key made by PBKDF2-SHA256 with 600,000 rounds and a fresh random salt. A wrong password or a changed file makes unlocking fail.
There is no recovery. If you lose the password, nobody can open the file, including us.
Encryption hides the content, not the fact that you have a file, and not its approximate size.