Attorney–client privilegeAttorney–client privilege or lawyer–client privilege is the common law doctrine of legal professional privilege in the United States. Attorney–client privilege is "[a] client's right to refuse to disclose and to prevent any other person from disclosing confidential communications between the client and the attorney." The attorney–client privilege is one of the oldest privileges for confidential communications.
Information sensitivityInformation sensitivity is the control of access to information or knowledge that might result in loss of an advantage or level of security if disclosed to others. Loss, misuse, modification, or unauthorized access to sensitive information can adversely affect the privacy or welfare of an individual, trade secrets of a business or even the security and international relations of a nation depending on the level of sensitivity and nature of the information. This refers to information that is already a matter of public record or knowledge.
Classified informationClassified information is material that a government body deems to be sensitive information that must be protected. Access is restricted by law or regulation to particular groups of people with the necessary security clearance and need to know, and mishandling of the material can incur criminal penalties. A formal security clearance is required to view or handle classified material. The clearance process requires a satisfactory background investigation.