Security enhancement for space telecommand link

Impressive advances in space technology are enabling complex missions, with potentially strong and long term impact on human life and activities. The peculiarities of space channels require a massive re-engineering of many of the protocols usually adopted in terrestrial networks; among them, security solutions are to be deeply reviewed, and tailored to the specific space requirements. In the context of civil space missions, the issue of securing communications gained a major attention in the last few years, mainly thanks to the activities promoted in this field by the Consultative Committee for Space Data Systems. Risk analyses performed by several space agencies have provided indications of the impact of different security threats on several categories of space missions. Focusing on security at the data link layer, a scalable and flexible authentication framework is proposed in this paper, for the CCSDS Telecommand specification, to meet the security and performance requirements of future space networks.