This document gives an overview of how security is designed into Google’s technical infrastructure. This global scale infrastructure is 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. We will describe the security of this infrastructure in progressive layers starting from the physical security of our data centers, continuing on to how the hardware and software that underlie the infrastructure are secured, and finally, describing the technical constraints and processes in place to support operational security. The security in the infrastructure is designed in layers starting from the physical components and data center, to hardware provenance, and then on to secure boot, secure inter-service communication, secured data at rest, protected access to services from the internet and finally, the technologies and people processes we deploy for operational security.