1. A method for processing data output from a computer system including a storage device and a processor, comprising: reading, with the processor, primitive data from the storage system, the primitive data being a minimum unit of significant information; reading, with the processor, the primitive data as original data from the storage system, the primitive data having the protection attribute set thereon; performing, with the processor, an operation on the original data to generate derived data; determining, with the processor, whether to make the derived data inherit the protection attribute of the original data by comparing the content of the operation performed on the original data with information for updating the protection attribute set in advance; determining, with the processor, a protection attribute of the primitive data on the basis of a type and a content of the primitive data, and, providing, with the processor, tag data containing the protection attribute to the derived data as the primitive data, wherein the tag data further contains a data type of the derived data, information on the original data that is a source of generation of the derived data, and history information on an operation executed to generate the derived data, wherein the tag data further contains a data type of the derived data, information on the original data that is a source of generation of the derived data, and history information on an operation executed to generate the derived data.