Now you can track the status of encryption policy settings in Security Center, including when they were last updated.
Where: This change applies to Lightning Experience and Salesforce Classic in Enterprise, Performance, Unlimited, and Developer editions.
Who: This change applies to editions that have the Shield Platform Encryption and the Security Center add-on subscriptions.
How: Monitor the Encryption Policy metric from your Security Center dashboard via the Configuration category in Security Overview.
Simplify Encryption Policy Management with the Encryption Policies Metric (salesforce.com)