There are three main types of sensitive information:
Personal information: Sensitive personally identifiable information (PII) is data that can be traced back to an individual and that, if disclosed, could result in harm to that person. Such information includes biometric data, medical information, personally identifiable financial information (PIFI) and unique identifiers such as passport or Social Security numbers. Threats include not only crimes such as identity theft but also disclosure of personal information that the individual would prefer remained private. Sensitive PII should be encrypted both in transit and at rest.
Business information: Sensitive business information includes anything that poses a risk to the company in question if discovered by a competitor or the general public. Such information includes trade secrets, acquisition plans, financial data and supplier and customer information, among other possibilities. With the ever-increasing amount of data generated by businesses, methods of protecting corporate information from unauthorized access are becoming integral to corporate security. These methods include metadata management and document sanitization.
Classified information: Classified information pertains to a government body and is restricted according to level of sensitivity (for example, restricted, confidential, secret and top secret). Information is generally classified to protect security. Once the risk of harm has passed or decreased, classified information may be declassified and, possibly, made public.