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Title: Building an FTP guard

Conference ·
OSTI ID:665974

Classified designs usually include lesser classified (including unclassified) components. An engineer working on such a design needs access to the various sub-designs at lower classification levels. For simplicity, the problem is presented with only two levels: high and low. If the low-classification component designs are stored in the high network, they become inaccessible to persons working on a low network. In order to keep the networks separate, the component designs may be duplicated in all networks, resulting in a synchronization problem. Alternatively, they may be stored in the low network and brought into the high network when needed. The latter solution results in the use of sneaker-net (copying the files from the low system to a tape and carrying the tape to a high system) or a file transfer guard. This paper shows how an FTP Guard was constructed and implemented without degrading the security of the underlying B3 platform. The paper then shows how the guard can be extended to an FTP proxy server or an HTTP proxy server. The extension is accomplished by allowing the high-side user to select among items that already exist on the low-side. No high-side data can be directly compromised by the extension, but a mechanism must be developed to handle the low-bandwidth covert channel that would be introduced by the application.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE Office of Financial Management and Controller, Washington, DC (United States)
DOE Contract Number:
AC04-94AL85000
OSTI ID:
665974
Report Number(s):
SAND-98-1426C; CONF-981010-; ON: DE98007164; BR: YN0100000; TRN: AHC29819%%128
Resource Relation:
Conference: National information systems security conference, Crystal City, VA (United States), 5-9 Oct 1998; Other Information: PBD: [1998]
Country of Publication:
United States
Language:
English