From Citizendium, the Citizens' Compendium
The Joint Worldwide Intelligence Communications System (JWICS) is a little misleading in its name, and even the usual comment that it is approved for "collateral" (TOP SECRET classification not belonging to a compartmented control system, as well as TS/SCI (sensitive compartmented information) and TS/SAP (special access program). Both SCI and SAP are compartmented control systems; the difference is that SCI is under the control of the United States intelligence community while SAP is under the control of the military.
Individual TS, SCI, or SAP applications will have individual user logins, and conceivably additional encryption. Indeed, since JWICS is an IP routed system, virtual private networks could be set up for additional security. As far as encryption, the essential part is that the cryptographic keys are provided, or approved, by the National Security Agency. Typical encryption devices include the TSEC/KG-194 and TSEC/KIV-7 link encryptors; approved protected distribution systems may be user.
JWICS also is an overlay on the Defense Information Systems Network (DISN). Certain other networks, both overlay and backbone, can interconnect, such as Intelink-C, also known as JDISS Four Eyes, over which Australia, Canada, the United Kingdom, and the United States share SCI. In the U.K., Stoneghost is the backbone network analogous to DISN.
Where JWICS is the communications network, DODUS Trusted Workstation (DTW) is the generally approved host software. Workstations are not the ony devices that connect, of course; there can be secure voice with STU-III or STE telephones, or various video teleconferencing centers (VTC).
As long as there is appropriate link encryption, a node, especially a mobile one such as a RC-135 RIVET JOINT communications intelligence aircraft, that node may send its information through a link equipped with TS/SCI approved encryption, to a ground JWICS entry point.