• Sensitivity of data
– A measure of the importance assigned to the data by its owner, for the purpose of denoting
its need for protection. Some databases contain only sensitive data while other databases
may contain no sensitive data at all. Handling databases that fall at these two extremes is
relatively easy, because these can be covered by access control, which is explained in the
next section. The situation becomes tricky when some of the data is sensitive while other
data is not.
• Several factors can cause data to be classified as sensitive:
– 1. Inherently sensitive.
• The value of the data itself may be so revealing or confidential that it becomes sensitive—for example, a
person’s salary or that a patient has HIV/AIDS.
– 2. From a sensitive source.
• The source of the data may indicate a need for secrecy—for example, an informer whose identity must
be kept secret.
– 3. Declared sensitive.
• The owner of the data may have explicitly declared it as sensitive.
– 4. A sensitive attribute or sensitive record.
• The particular attribute or record may have been declared sensitive—for example, the salary attribute of
an employee or the salary history record in a personnel database.
– 5. Sensitive in relation to previously disclosed data.
• Some data may not be sensitive by itself but will become sensitive in the presence of some other data
—for example, the exact latitude and longitude information for a location where some previously
recorded event happened that was later deemed sensitive