Joint Worldwide Intelligence Communications System

The Joint Worldwide Intelligence Communication System (JWICS, /ˈdʒeɪwɪks/ JAY-wiks) is the United States government's secure intranet for the storage of top secret and sensitive compartmented information, primarily for use in intelligence. It is the most secure of three separate router networks operated by the U.S. government for the handling and transmission of classified materials and is designed to safeguard the most sensitive materials. Operated by the Department of Defense, JWICS superseded DSNET2 and DSNET3, the Top Secret and SCI levels of the earlier Defense Data Network.

Most of the publicly known compromises of JWICS have been perpetrated by leakers who had legitimate authorization to access the system at the time of their disclosures, including: Chelsea Manning in 2010, Edward Snowden in 2013, and Jack Teixeira in 2023. Because of the sensitivity of its contents, JWICS remains a frequent subject of discussion and concern surrounding the United States' vulnerability to cyber threats.

The Joint Worldwide Intelligence Communications System (JWICS) is a secure intranet system utilized by the United States Department of Defense to house "Top Secret/Sensitive Compartmented Information" In day-to-day usage, the JWICS is used primarily by members of the Intelligence Community, such as the DIA within the DoD, and the Federal Bureau of Investigation under the Justice Department. Conversely, SIPRNet and NIPRNet account for the overwhelming bulk of usage within DoD and non-intelligence government agencies and departments.

There are three main router networks operated by the Department of Defense. Each is separated by the types of information they deal with.

At the most open level, the Non-Classified Internet Protocol Router Network (NIPRNET) is the hub for non-classified but still specialized information relating to important logistics and planning.

Above this lies the Secret Internet Protocol Router Network (SIPRNET). SIPRNET deals with information classified as Confidential or Secret. SIPRNET is another of the networks accessed by Chelsea Manning (See Automation bias, JWICS, WikiLeaks, and Chelsea Manning).

Finally, the Joint Worldwide Intelligence Communications System houses the top level of data, consisting primarily of top-secret intelligence information. The system deals with transmissions coming from across the globe. The transmission of information across the JWICS network is summarized by Jeffrey R. Cares in the Encyclopedia of Cyber Warfare: See Joint All-Domain Command and Control

JWICS can utilize satellite network connections, and the traffic moving across the network can be sent in prioritized premarked packets, meaning that the most important and sensitive information can be sent on the fastest and most secure routes ... Once transmitted, the information is housed on JWICS and is accessible from "highly secured rooms known as Secret Compartmentalized Information Facilities. Such rooms are incredibly important facilities, and can be highly vulnerable if compromised.