The most valuable thing in this world is information. All people act on information. Since humans are fighting various battles in a competitive society, confidentiality of information becomes important. Regardless of the times, importance of information is important from ancient times. As a result, the taxi family who carried out "the fortune-tellinger of the future information" had a high social status and carried out "the development of the information network based on mail delivery", became the first aristocrat. It is security to safely manage the valuable information. It is information security that includes everything from attacks such as cyber terrorism, leaks inside the company, and spies.