Kafka Security up to date matrials

Greetings,
I’m learning about security, how to set up and use SSL. There are many materials out there and I’m curious if these are up to date:
Encryption and authentication → Encryption and Authentication with SSL — Confluent Documentation
using SSL with confluent docker images: Clustered Deployment Using SSL — Confluent Platform 3.3.0
If you have better resources to share, please don’t hesitate

Kafka Definitive Guide is a free ebook (can be downloaded from the Confluent page somewhere) which is a pretty good resource for Kafka ops. It’s indeed a bit dated (3-4 years?), but I don’t think that much has changed in regards to the security.

Thanks @weeco . I do have that book, but it was written 3 years ago, so I thought it might have been outdated. I also think that there is not much changes in the security.