Improving Security of Space Link Extension (SLE) Services

Abstract

The CCSDS Recommendations for Space Link Extension (SLE) transfer services are becoming the predominant internationally accepted standard for interoperability between TT&C networks and mission user facilities. With increasing use of Space Link Extension (SLE) services the need to secure the communication via SLE interfaces increases as well. The SLE Recommendations include some basic precautions supporting simple authentication but for most security aspects rely on the underlying protocol suite or on measures implemented by applications using SLE services. This paper will discuss options to improve security of SLE services within the current standardization scope and will report on the design of an application layer security filter for SLE services, the SLE Sentry.