Privacy as an ethical and social issue has long been studied by philosophers, social scientists, and legal scholars around the world. The classic approach dates back to 1890 and the remarks by judges S. Warren and L. Brandeis in the USA that privacy refers to "... the right of an individual to be let alone."

Later, the protection of privacy was recognized as a fundamental human right in the United Nations Declaration of Human Rights, the International Covenant on Civil and Political Rights, was included in the Fundamental Rights of citizens of the European Union, and in a series of other texts and international conventions.

Over time, the classic perception of privacy has been significantly enriched with specific rights such as the right to private life, limiting accessibility, exclusive control of access to private space, minimization of "interventions," the expectation of confidentiality, the right to secrecy, and the right to anonymity.

Meanwhile, the rapid development of information and communication technology and their swift convergence have led to the development of electronic and other services aimed at improving citizens' lives, enabling easier and more immediate communication and information exchange using the Internet, and leveraging the World Wide Web in the realm of e-commerce, etc.

In this area, however, the decentralization of data processing and the penetration of networking into almost all human activity radically change the environment for using personal information, raising significant issues regarding the protection of privacy in the digital world.

This collective volume presents comprehensively, for the first time in Greek literature:

• Technological issues aimed at protecting privacy (e.g., privacy-enhancing technologies, privacy protection technologies in digital community environments, applications utilizing RFID, technical measures for implementing pseudonymity and ensuring anonymity, privacy protection mechanisms in wireless and mobile communication networks, fourth-generation networks and wireless sensor networks, privacy protection technologies in distributed data mining systems, technical privacy protection issues in electronic voting environments, mathematical models for calculating the cost of privacy protection, etc.)
• Legal issues arising in the digital world (e.g., privacy protection in social networks, privacy and the utilization of RFID applications, privacy in e-governance environments, in medical information systems applications, protection of confidentiality in electronic communications, intellectual property law and personal data protection, legal assurance of confidentiality in mobile communications, etc.)