In a secured Kafka cluster, the Confluent Schema Registry needs to be configured to communicate with Kafka using an authenticated SASL mechanism, and it requires privileges to register schemas with Kafka. The schema registry must also secure its communication with clients. To achieve this, the schema registry principal is set to [email protected], and the JAAS file is configured accordingly. The schema registry needs to connect to ZooKeeper using a specific principal, and it requires authorization for write operations on a Kafka topic named _schemas. Additionally, the schema registry user must be authorized to read from this topic, and a stable group ID is crucial for Kafka security stability. To secure communication between the schema registry and its clients, HTTPS can be enabled, which encrypts all REST API calls.