Today, due to the rapid development of technology and communication, personal rights can be damaged. In particular, the electronic processing of personal data, which is a part of personal rights, may cause problems in terms of data security. Therefore, as a result of the development of technology and communication, all kinds of information should be able to move freely, and at the same time, fundamental rights dependent on the person should be protected. By clarifying the concepts of data, personal data, and data processing, the study examines the reliability of the data processed in the light of these concepts at the point of data security.