  This paper presents a blockchain-based approach for securing spectrum sharing
in multi-beam satellite systems. Satellite spectrum is a scarce resource that
requires highly efficient management schemes for optimized sharing by network
users. However, spectrum sharing is vulnerable to attacks by malicious protocol
participants. In order to ensure efficient spectrum management in the face of
dishonest satellite users or cyber attackers, it is important for spectrum
sharing mechanism to provide transparency and traceability of the trading
process so as to enable the system to detect, and hence eliminate, unauthorized
access by malicious users. We address these requirements by proposing the use
of blockchain which, apart from its ability to provide transparency and
traceability, ensures an immutable means for keeping track of user trading
reputation. Besides, in order to address the practical constraints of
heterogeneous user nodes, we also propose the use of edge computing to support
users with limited computing power. In this paper, we propose a
blockchain-based spectrum trading framework and, based on which, a multibeam
satellite spectrum sharing algorithm for interference pricing and heterogeneous
spectrum demands is devised to improve the efficiency of satellite spectrum. By
leveraging on the system characteristics of blockchain, a dynamic spectrum
sharing mechanism with traceability, openness and transparency for whole
trading process is presented. Numerical results are also provided to evaluate
the system benefits and spectrum pricing of the proposed mechanism.
