# Security level for state synchronization

Because synchronization controls the inter-node traffic within a heartbeat network, you must ensure the security of the heartbeat and synchronization data.

Traffic between nodes can be authenticated, or both authenticated and encrypted. Traffic between nodes can also optionally be sent without authentication or encryption. However, this makes it possible to both sniff synchronization data and send fraudulent messages to open connections.
Note: Independent of the security level, all critical information such as passwords and encryption keys are protected. They are never sent in plaintext.