To protect data in such a way that parties other than prescribed users cannot use the data stored in a device or a recording medium as well as data that are being transmitted, by using the data with respect to fingerprints or the voice print of a prescribed user.

A protection data generating means 6 generates protection data, by directly imbedding information of a specific part of prescribed users, such as fingerprint data or information generated from a part of the bodies of the prescribed users, such as voice print to base data that are to be protected. Furthermore, a data-separation means uses the information of specific parts of the body of the prescribed users, such as the fingerprint data or the information generated from parts of the body of the prescribed users, such as voice print to separate the base data from the protection data, so as to allow only the prescribed users to utilize the base data contents.