From the post:
The daily life of a Spy in service to the Rebellion is one of flexibility and innovation. Every mission poses a new question that must be answered with minimal supplies and personnel against a foe with a surplus of both. The Rebellion relies on the ingenuity and skill of every single operative on their roster. Today, we're going to look a little closer at the secrets revealed in the newest Star Wars™: Age of Rebellion sourcebook, Cyphers and Masks.