By definition, operational security was derived from the military term procedural security, which originated as a term that described strategies to prevent potential adversaries from discovering critical operations-related data. Which is an analytical process that classifies information assets and determines the control required to provide these assets.
You might wonder why I choose to write about both physical and digital operational security? The simplest answer is they’re intertwined and can’t be separated in my opinion. If you have one but not the other it’s just like you don’t have any.