1. A method comprising: inputting first document data including a plurality of components and signature information corresponding to each of the components, wherein the signature information is calculated according to a digest value of a corresponding component and a private key, and wherein the plurality of components comprise at least document information and transmission information, wherein the document information comprises at least one of an attribute, layout information, character code string, and document logical construction, and wherein the transmission information comprises information required for rendering processing; selecting at least one component from among the plurality of components; extracting signature information corresponding to the at least one selected component; storing the at least one selected component and the signature information corresponding to the at least one selected component separately in a memory; and generating second document data by pasting the at least one stored component and the stored signature information, wherein the signature information includes pointer information corresponding to the at least one selected component, and wherein the extracting step comprises extracting the pointer information.
1. A method comprising: inputting first document data including a plurality of components and signature information corresponding to each of the components, wherein the signature information is calculated according to a digest value of a corresponding component and a private key, and wherein the plurality of components comprise at least document information and transmission information, wherein the document information comprises at least one of an attribute, layout information, character code string, and document logical construction, and wherein the transmission information comprises information required for rendering processing; selecting at least one component from among the plurality of components; extracting signature information corresponding to the at least one selected component; storing the at least one selected component and the signature information corresponding to the at least one selected component separately in a memory; and generating second document data by pasting the at least one stored component and the stored signature information, wherein the signature information includes pointer information corresponding to the at least one selected component, and wherein the extracting step comprises extracting the pointer information. 3. The method according to claim 1 , wherein the first document data includes a table indicating correspondence between each of the plurality of components and the signature information corresponding to the components, and wherein the signature information corresponding to the at least one selected component is extracted from the table.