I am using millenium BR-Ds for data backup. And I encrypt these disks following current state-of-the-art encryption, which is luks dm-crypt as described e.g. here http://www.troubleshooters.com/lpm/201408/201408.htm#luksbluray_objective

Currently this can only be done manually, as k3b has no option to create an encrypted data project. Ideally there should be an option on the data project properties that allows to enable encryption and set the up to 8 password for the luks password slots. Even better it could be listed as "encrypted data project" and prompt for the password(s) and set such an encrypted data project up.

The required tools for doing this are stable and available on all systems. See the link for a description how this is manually done.

Reproducible: Always

Steps to Reproduce:
1. Try to create an encrypted data project
2. Find out that k3b does not support / offer it
3. Then do it all manually and don't use k3b

Actual Results:  
Works only manually

Expected Results:  
Would be nice if it was supported

That is the usual vicious circle for encryption. Most people know they should use it but it is too much off a hassle for them to use it. As no one uses it, most programs don't support it. No support = almost no one uses it. Catch 22.