Abstract: In a dynamic spectrum management apparatus, system, method, and computer program product first and second priority level secondary users dynamically use spectrum resources of a primary user. For second priority level secondary users, processing circuitry is configured to, based on blockchain, obtain a spectrum coordination request, acknowledged by a spectrum management apparatus, of another second priority level secondary user serving as a requester for the spectrum resources, wherein the blockchain at least comprises each second priority level secondary user, who is using or requests the use of the spectrum resources, serving as a node, and the spectrum coordination request indicates that the requester makes a request for the second priority level secondary user, who is using the spectrum resources, to perform coordination to provide an interference margin for the requester; and execute a first smart contract on the blockchain, so as to determine content of coordination to be performed.