- Date: 1759
- 1 : marked by intimacy or willingness to confide <a confidential tone>
- 2 : private, secret <confidential information>
- 3 : entrusted with confidences <a confidential clerk>
- 4 : containing information whose unauthorized disclosure could be prejudicial to the national interest
Confidentiality has been defined by the International Organization for Standardization (ISO) in ISO-17799 as "ensuring that information is accessible only to those authorized to have access" and is one of the cornerstones of information security. Confidentiality is one of the design goals for many cryptosystems, made possible in practice by the techniques of modern cryptography.
Confidentiality also refers to an ethical principle associated with several professions (e.g., medicine, law, religion, professional psychology, and journalism). In ethics, and (in some places) in law and alternative forms of legal dispute resolution such as mediation, some types of communication between a person and one of these professionals are "privileged" and may not be discussed or divulged to third parties. In those jurisdictions in which the law makes provision for such confidentiality, there are usually penalties for its violation.
Confidentiality of information, enforced in an adaptation of the military's classic "need-to-know" principle, forms the cornerstone of information security in today's corporations. The so called 'confidentiality bubble' restricts information flows, with both positive and negative consequences.