The Cloud Native Computing Foundation (CNCF) has adopted the key-value store etcd that is a central (albeit distributed) component of Kubernetes. etcd has been developed by the CoreOS company that has been acquired by Red Hat in early 2018. It's a distributed key-value store similar to Apache Zookeeper or Hashicorp's consul that ensures reliability through the Raft consensus protocol. For secure communication etc is using TLS encryption.