Explanation/Reference: https://en.wikipedia.org/wiki/Apache_Solr

Secure Internal Communication (SIC)SecureInternal Communication (SIC) lets Check
Point platforms and products authenticate with each other. The SIC procedure creates a trusted status between gateways, management servers and other Check Point components. SIC is required to install polices on gateways and to send logs between gateways and management servers.
These security measures make sure of the safety of SIC:

Administrator Collaboration
More than one administrator can connect to the Security Management Server at the same time. Every administrator has their own username, and works in a session that is independent of the other administrators.
When an administrator logs in to the Security Management Server through SmartConsole, a new editing session starts. The changes that the administrator makes during the session are only available to that administrator. Other administrators see a lock icon on object and rules that are being edited.
To make changes available to all administrators, and to unlock the objects and rules that are being edited, the administrator must publish the session.

Explanation
Explanation/Reference: https://sc1.checkpoint.com/documents/R76/CP_R76_Installation_and_Upgrade_Guide- webAdmin/13128.htm