If you have more than you on the server, sure, you can secure it.
I have an ElastiCache cluster setup at AWS and I have no security setup within Redis itself. I use routing for security, so only my servers can speak to my Redis cluster on a private VPC. And it's not open to the Internet.
If you're running it locally on the same machine, still nothing else required for external connections, since I believe it's only listening for 127.0.0.1 connections