Critical systems and infrastructure rely heavily on ICT systems and networks where security issues are a major concern. Authentication methods verify that messages come from trusted sources and guarantee the smooth flow of information and data. In this edited reference, the authors present state-of-art research and development in authentication technologies including challenges and applications for Cloud Technologies, IoT and Big Data. Topics covered include authentication; cryptographic algorithms; digital watermarking; biometric authentication; block ciphers with applications in IoT; identification schemes for Cloud and IoT; authentication issues for Cloud applications; cryptography engines for Cloud based on FPGA; and data protection laws.

There are a growing number of challenges in handling medical data in order to provide an effective healthcare service in real-time. Bridging the gap between patient expectations and their experiences needs effective collaboration and connectivity across the healthcare ecosystem. The success of joined-up care relies on patient data being shared between all active stakeholders, including hospitals, outreach workers, and GPs. All these needs and challenges pave the way for the next trend of development in healthcare - healthcare 4.0.