Google is an internet powerhouse and has been building core services and infrastructure, and security has been imperative to Google throughout its journey. Google has security built through layers, from data center security all the way to application and information management. The following diagram gives you a good idea of this layered security approach at Google, along with the different capabilities and features at each layer:
The lowest layer is the hardware infrastructure security, which includes physical security, hardware security, and machine boot stack security. Google designs and fully owns and manages its data centers, and access to these data centers is highly restricted. A fun fact is that Google even uses laser-based intrusion detection systems at their physical data center locations. Google also has some co-location functions...