Description

BigQuery by default encrypts data at rest by employing Envelope Encryption using Google managed cryptographic keys. The data is encrypted using the data encryption keys and data encryption keys themselves are further encrypted using key encryption keys. This is seamless and does not require any additional input from the user. However, if you want greater control, customer-managed encryption keys (CMEK) can be used as an encryption key management solution for BigQuery datasets.

Rationale

BigQuery by default encrypts data at rest by employing Envelope Encryption using Google managed cryptographic keys. This is seamless and does not require any additional input from the user.

For greater control over encryption, customer-managed encryption keys (CMEK) can be used as an encryption key management solution for BigQuery datasets. Setting a default customer-managed encryption key (CMEK) for a dataset ensures any tables created in the future will use the specified CMEK if none other is provided.

Note: Google does not store your keys on its servers and cannot access your protected data unless you provide the key. This also means that if you forget or lose your key, there is no way for Google to recover the key or to recover any data encrypted with the lost key.

Impact

Using Customer-managed encryption keys (CMEK) will incur additional labor-hour investment to create, protect, and manage the keys.

Audit

From Google Cloud Console

1. Go to Analytics
2. Go to BigQuery
3. Under Analysis click on SQL Workspaces, select the project
4. Select Data Set
5. Ensure Customer-managed key is present under Dataset info section.
6. Repeat for each data set in all projects.

From Google Cloud CLI

List all dataset names

bq ls

Use the following command to view each dataset's details.

bq show {{data-set-object}}

Verify the kmsKeyName is present.

Default Value

Google Managed keys are used as key encryption keys.

References

1. https://cloud.google.com/bigquery/docs/customer-managed-encryption