How to create an encrypted zip file on Linux

The zip command line tool provides an encryption option. The encryption algorithm used by zip command is PKZIP stream cipher. The PKZIP algorithm is known to be insecure. Also, the fact that the password is typed and shown in plain text makes it even more vulnerable.

To create an encrypted zip file with zip:

$ zip --password MY_SECRET secure.zip doc.pdf doc2.pdf doc3.pdf

To uncompress a zip file that is encrypted with zip command:

$ unzip secure.zip

Archive:  secure.zip
[secure.zip] doc.pdf password: