Information leakage refers to the leaking of "internal" information, such as personal information and confidential company information, to the outside world. As a social problem, it started to attract attention around the year 2000. The popularization of the internet and company intranets occurring at that time, which made it easy to access data and simple to send data to the outside, was behind the outbreak of information leakage.
From the viewpoint of business, information leakage is connected to many detrimental effects, like loss of social confidence. Consequently, individual companies are implementing various countermeasures against information leakage.
At first, information leakage by electronic data was mainly focused on; consequently, it is becoming possible to suppress this type of information leakage by various countermeasures. On the other hand, countermeasures against information leakage by paper media are way behind. A countermeasure to protect all information from leakage—including that by paper media—is thus demanded.
