Trend Vision One provides comprehensive security measures to protect the Service Gateway OS. The security features include:

• Secure Boot
• Firewall
• Encryption
• Access Control

The V1 Service Gateway hardening is also same with the previously posted Service Gateway hardening KB. Please refer to this KB article for the high level information:
https://success.trendmicro.com/solution/KA-0013832

Sharing this online help article for more information on the V1 Service Gateway:
Getting started with Service Gateway  | Trend Micro Service Central

For more detailed information on the security measures applied on the Service Gateway OS, please refer to the documentation provided by Trend Micro. The documentation can be found on the Trend Micro website or by contacting Trend Micro support.