cut-off
n.— «The early cassettes were delivered to the office of al-Jazeera in an Islamabad suburb. America was watching, but to no avail. “They did it at night using cut-offs,” says one official, using the term for someone who does not know his employer. “It’s one of the most reliable measures in spycraft.”» —“The hunt” by Declan Walsh Guardian (United Kingdom) Sept. 11, 2006. (source: Double-Tongued Dictionary)
The term usually used for this concept is “cut-out.”