Privacy as an ethical and social issue has been studied extensively by philosophers, social scientists, and lawyers worldwide. The classical approach dates back to 1890 and the reference made by judges S. Warren and L. Brandeis in the US that privacy refers to "...the right of an individual to be let alone." Later on, the protection of privacy was recognized as a fundamental human right in the Universal Declaration of Human Rights, the International Covenant on Civil and Political Rights, incorporated into the Fundamental Rights of the European Union, and in a series of other texts and international conventions.

Over time, the classical understanding of privacy has significantly evolved to include individual rights such as the right to private life, limitation of accessibility, exclusive control of access to private space, minimization of "intrusions," expectation of confidentiality, the right to privacy and anonymity.

Meanwhile, the rapid development of information technology and communication and their rapid convergence have led to the development of electronic and other services aimed at improving the lives of citizens, facilitating easier and more direct communication and information exchange using the Internet, and utilizing the World Wide Web (Web) in the field of e-commerce, among others. However, in this context, the decentralization of data processing and the penetration of networking into almost all human activities radically change the environment for the use of personal information, raising significant issues regarding the protection of privacy in the digital world.

This collective volume presents comprehensive, for the first time in Greek literature:
- Technological issues aimed at protecting privacy (e.g., privacy-enhancing technologies, privacy protection technologies in digital communities, applications of RFID utilization, technical measures for pseudonymity implementation and anonymity assurance, 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 issues in privacy protection in electronic voting environments, mathematical models for computing the cost of privacy protection, etc.)

- Legal issues arising in the digital world (e.g., privacy protection in social networks, privacy and RFID application utilization, 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.)