ELECTRONIC DATA AUTHENTICITY ASSURANCE METHOD AND PROGRAM

The present invention provides an electronic document authenticity assuring method in which a series of procedures concerning redactable signature are divided into procedures dependent on a document to be signed and procedures dependent on a redactable signature method. Further, the present invention provides program codes that realize the divided procedures and a system comprising apparatuses for implementing those program codes. According to the present invention, even when type of electronic document to be signed is changed or added to, it is sufficient to add a procedure dependent on a document to be signed, without changing procedures dependent on redactable signature methods. Similarly, even when a redactable signature method is to be changed or added, it is sufficient to add a procedure dependent on the redactable signature method without changing procedures dependent on document to be signed.