During silent collection, the system builds a device history and behavioral profile for each user, and does not require the user to provide identity confirmation.
In the Security Console, click Authentication > Policies > Risk-Based Authentication Policies > Manage Existing.
Click the policy that you want to configure, and select Edit.
In the Device Registration and Identity Confirmation Settings section, select one of the following for Silent Collection Period:
Allow silent collection. Enables silent collection and enter the number of days that you want silent collection enabled for each user.
Do not allow silent collection. Disables silent collection.