Provided a proof of play (PoP) method of a digital signage terminal and a digital signage server, the PoP method of the digital signage terminal including obtaining a digital signature and a PoP message generation policy provided by a content owner, generating log data comprising information on a play of at least one piece of content, based on the PoP message generation policy, generating a PoP message using information on the digital signature based on the generated log data, and providing the PoP message to at least one of the digital signage server and the content owner.