air gap

plural air gaps · alternative airgap

1. computer securitycomputingA network security measure that consists of ensuring that a secure computer network is physically isolated from unsecured networks, such as the public Internet or an unsecured local area network.

   The structure and design of Stuxnet confirms the Iranian air gap, as the attackers clearly designed Stuxnet to jump an air gap utilizing multiple methods.

   2016, William D. Bryant, International Conflict and Cyberspace Superiority: Theory and Practice, Routledge, →ISBN, page 153

   1 more example

   The day after Lindsay left, I took an emergency medical leave of absence from work, citing epilepsy, and packed scant luggage and four laptops: secure communications, normal communications, a decoy, and an “airgap” (a computer that had never gone and would never go online).

   2019 September 17, Edward Snowden, Permanent Record, New York, N.Y.: Metropolitan Books/Henry Holt and Company, →ISBN

   Synonyms: airwall

2. A gap where there is a vacuum (not actually air), used to reduce power consumption in microelectronics.
3. A type of spark gap using a tube filled with air (which is mostly nitrogen), nitrogen alone, or other gases.