Confidentiality refers to the boundaries surrounding shared secrets and to the process of guarding these boundaries. While confidentiality protects much that is not in fact secret, personal secrets lie at its core. The innermost, the vulnerable, often the shameful: these aspects of self-disclosure help explain why one name for professional confidentiality has been "the professional secret." Such secrecy is sometimes mistakenly confused with privacy; yet it can concern many matters in no way private, but that someone wishes to keep from the knowledge of third parties.
Sissela Bok (2011). “Secrets: On the Ethics of Concealment and Revelation”, p.119, Vintage