Your data is encrypted in transit by default
By default, when a user connects to Google Cloud, the connection between the user and Google is encrypted. That means that when you connect to Google Cloud, the data you send is encrypted using HTTPS, so that an adversary cannot snoop on your traffic. (You can find out more about HTTPS at Google in our HTTPS transparency report.) Google implements TLS and other encryption in transit protocols by using BoringSSL, an open-source cryptographic library derived from OpenSSL.
By default, Google Cloud encrypts and authenticates all data in transit at one or more network layers when data moves outside physical boundaries not controlled by or on behalf of Google. For comparison, data in transit inside a physical boundary is authenticated but not necessarily encrypted because rigorous security controls are already in place. To ensure protection of data against any potential threats, GCP’s inherent assumption is that the wide area network is only semi-trusted — that is, that network links between physical boundaries can be compromised by an active adversary who can snoop, inject or alter traffic on the wire. Encrypting data in transit helps protect against this type of activity.
At the network layer, Google Cloud’s virtual network infrastructure automatically encrypts VM to VM traffic if it crosses a physical boundary not controlled by or on behalf of Google. On top of this, at the application layer, Application Layer Transport Security automatically provides authentication, integrity and encryption of remote procedure calls from service to service, when those calls leave a physical boundary controlled by or on behalf of Google. Each service that runs in Google’s infrastructure has a service account identity with associated cryptographic credentials that are used to authenticate these communications.
You have additional options to encrypt your data in transit
In addition to default protections, Google Cloud customers have many options to further encrypt data in transit, including IPsec tunnels, free and automated TLS certificates.
With Google Cloud VPN, you can send requests from your on-premise machine to a service hosted on Google Cloud through a secure, IPsec VPN tunnel at the network layer. You can also set up multiple, load-balanced tunnels through multiple VPN gateways.