Need to Know

The phrase need to know is use to describe information that is only given based on what a person needs in order to do their job and nothing further. It is a method of maintaining confidential information.

Example:

Our mission was too critical to fail. The legislation had to pass. The entire plan hinged on secrecy so everyone outside of the inner circle was operating on a need-to-know basis in the hopes that compartmentalizing our activities would prevent anyone from being able to piece the entire thing together and leak the information.