Blockchain, an emerging technology first adopted in digital currencies and financial transactions, is gaining attention as promising solutions to the above-mentioned challenges. Blockchain is founded on distributed ledger technologies, incorporating advanced security features, such as cryptographic signature technologies and cement transparency and trust between advertisers and publishers. With Blockchain the need for intermediaries is limited, all campaign and personal data of the viewers are stored encrypted in the blockchain, providing transparency to the advertising model and, consequently, increasing the value of advertising across the ecosystem. In this paper we present an innovative approach for developing a blockchain enabled ad serving and management service, named VidAdChain, which we develop as the next gen solution of the established in the Greek advertising market, Vidads© video ad server. The service targets the digital video advertising segment of the market, due to the increasing significance of video in the digital advertising mix. Nonetheless, the core features of the present technological solution can find applications in all forms of digital advertising (banners, rich media, native ads etc.). Our research demonstrates that blockchain technology can effectively mitigate ad fraud by recording ad-related data on an immutable ledger, providing accurate and reliable information about ad performance. Moreover, the decentralized nature of blockchain enables real-time data access, automated transactions, and streamlined payments. However, challenges related to scalability, user privacy, and regulatory compliance need to be addressed for widespread adoption. This paper concludes that developing a blockchain video ad server has the potential to revolutionize the advertising industry by improving the integrity and efficiency of video ad serving, and further research and development in this field are crucial for its full realization