Background: This article explains the different ways in which data can be encrypted within a ServiceNow instance
Encryption within ServiceNow instances
By default, ServiceNow instances use standard HTTPS which means all communications between the browser and the website are encrypted.
In addition, customers can use Edge Encryption and Encryption Support plugins to further secure their instance.
Edge Encryption plugin is intended to work instance wide. Here is documentation on Edge Encryption plugin:
Encryption Support on the other hand is intended to work at the field level for fields that are of Encrypted type in the dictionary. Here is documentation on Encryption Support plugin:
Additionally, the white paper below describes data encryption within ServiceNow in detail: