Google Infrastructure Security Design Overview
Google Cloud Whitepaper
Google has a global scale technical infrastructure designed to provide security through the entire information processing lifecycle at Google. This infrastructure provides secure deployment of services, secure storage of data with end user privacy safeguards, secure communications between services, secure and private communication with customers over the internet, and safe operation by administrators.
Google uses this infrastructure to build its internet services, including both consumer services such as Search, Gmail, and Photos, and enterprise services such as G Suite and Google Cloud Platform.