  Regulatory radio spectrum management is evolving from traditional static
frequency allocation and assignment schemes towards dynamic spectrum management
and access schemes. This evolution is necessitated by a number of factors
including underutilization of licensed spectrum bands, changing market and
technological developments and increased demand for spectrum for emerging
applications in multimedia communications, internet-of-things and fifth
generation (5G) wireless networks. In simple terms dynamic spectrum management
involves allowing unlicensed users known as secondary users (SUs) to access the
licensed spectrum of a licensed user also known as primary user (PU). This is
primarily achieved using spectrum sharing schemes that leverage spectrum
database and cognitive radio techniques. However, the use of spectrum database
and cognitive radio techniques faces reliability, security and privacy concerns
for spectrum sharing. There is also a need to support other requirements of
dynamic spectrum management such as secondary spectrum trading market and
dynamic spectrum access coordination. In this work, we review the use of
blockchains for enabling spectrum sharing and other aspects of dynamic spectrum
management. The review covers the use of blockchain to record spectrum
management information such as spectrum sensing results and spectrum auction
transactions in a secure manner. The article also covers the use of smart
contracts to support complex service-levelagreements (SLAs) between network
operators which is key to supporting a self-organized secondary spectrum
sharing market and enforcement of regulatory policies. A taxonomy of the
intersection between blockchain and various concepts of dynamic spectrum
management is also provided
