Biblio
Renewed focus on spacecraft networking by government and private industry promises to establish interoperable communications infrastructures and enable distributed computing in multi-nodal systems. Planned near-Earth and cislunar missions by NASA and others evidence the start of building this networking vision. Working with space agencies, academia, and industry, NASA has developed a suite of communications protocols and algorithms collectively referred to as Delay-Tolerant Networking (DTN) to support an interoperable space network. Included in the DTN protocol suite is a security protocol - the Bundle Protocol Security Protocol - which provides the kind of delay-tolerant, transport-layer security needed for cislunar and deep-space trusted networking. We present an analysis of the lifecycle of security operations inherent in a space network with a focus on the DTN-enabled space networking paradigm. This analysis defines three security-related roles for spacecraft (Security Sources, verifiers, and acceptors) and associates a series of critical processing events with each of these roles. We then define the set of required and optional actions associated with these security events. Finally, we present a series of best practices associated with policy configurations that are unique to the space-network security problem. Framing space network security policy as a mapping of security actions to security events provides the details necessary for making trusted networks semantically interoperable. Finally, this method is flexible enough to allow for customization even while providing a unifying core set of mandatory security actions.
Satellite networks play an important role in realizing the combination of the space networks and ground networks as well as the global coverage of the Internet. However, due to the limitation of bandwidth resource, compared with ground network, space backbone networks are more likely to become victims of DDoS attacks. Therefore, we hypothesize an attack scenario that DDoS attackers make reflection amplification attacks, colluding with terminal devices accessing space backbone network, and exhaust bandwidth resources, resulting in degradation of data transmission and service delivery. Finally, we propose some plain countermeasures to provide solutions for future researchers.
Traditionally, the focus of security and ensuring confidentiality, integrity, and availability of data in spacecraft systems has been on the ground segment and the uplink/downlink components. Although these are the most obvious attack vectors, potential security risks against the satellite's platform is also a serious concern. This paper discusses a notional satellite architecture and explores security vulnerabilities using a systems-level approach. Viewing attacks through this paradigm highlights several potential attack vectors that conventional satellite security approaches fail to consider. If left undetected, these could yield physical effects limiting the satellite's mission or performance. The approach presented aids in risk analysis and gives insight into architectural design considerations which improve the system's overall resiliency.
The incorporation of security mechanisms to protect spacecraft's TT&c; payload links is becoming a constant requirement in many space missions. More advanced mission concepts will allow spacecrafts to have higher levels of autonomy, which includes performing key management operations independently of control centers. This is especially beneficial to support missions operating distantly from Earth. In order to support such levels of autonomy, key agreement is one approach that allows spacecrafts to establish new cryptographic keys as they deem necessary. This work introduces an approach based on a trusted platform module that allows for key agreement to be performed with minimal computational efforts and protocol iterations. Besides, it allows for opportunistic control center reporting while avoiding man-in-the-middle and replay attacks.