Zip a Text File using 256-AES Encryption

Use the following command:

17z a -p -mem=AES256 -tzip file.zip source-file1.txt source-file2.txt

It will ask for a password but will obviously not be echoed.

To decrypt:

17za e file.zip

You need to install as well associated tools. Shown are for Redhat-like Linux:

1sudo yum install p7zip p7zip-plugins

Some details https://unix.stackexchange.com/questions/182573/how-strong-is-the-encryption-of-a-zip-file-in-linux-mint and https://www.2daygeek.com/zip-7zip-encrypt-decrypt-password-protect-files-folders-linux/