  Space situation awareness (SSA) includes tracking of active and inactive
resident space objects (RSOs) and assessing the space environment through
sensor data collection and processing. To enhance SSA, the dynamic data-driven
applications systems (DDDAS) framework couples on-line data with off-line
models to enhance system performance. Using feedback control, sensor
management, and communications reliability. For information management, there
is a need for identity authentication and access control to ensure the
integrity of exchanged data as well as to grant authorized entities access
right to data and services. Due to decentralization and heterogeneity of SSA
systems, it is challenging to build an efficient centralized access control
system, which could either be a performance bottleneck or the single point of
failure. Inspired by the blockchain and smart contract technology, this paper
introduces BlendCAC, a decentralized authentication and capability-based access
control mechanism to enable effective protection for devices, services and
information in SSA networks. To achieve secure identity authentication, the
BlendCAC leverages the blockchain to create virtual trust zones and a robust
identity-based capability token management strategy is proposed. A
proof-of-concept prototype has been implemented on both resources-constrained
devices and more powerful computing devices, and is tested on a private
Ethereum blockchain network. The experimental results demonstrate the
feasibility of the BlendCAC scheme to offer a decentralized, scalable,
lightweight and fine-grained access control solution for space system towards
SSA.
