This book highlights advances in cyber security, cyber situational awareness (CyberSA), artificial intelligence (AI) and social media. It brings together original discussions, ideas, concepts and outcomes from research and innovation from multidisciplinary experts. It offers topical, timely and emerging original innovations and research results in cyber situational awareness, security analytics, cyber physical systems, blockchain technologies, machine learning, social media and wearables, protection of online digital service, cyber incident response, containment, control and countermeasures (CIRC3). The theme of Cyber Science 2023 is multidisciplinary and multidimensional cyber security. And through call for papers, we solicit original contributions advancing research in artificial intelligence, machine learning, blockchain, cyber security, social media, cyber incident response and cyber insurance.