| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic document protection device which can detect effectively forgery and an alteration of an electronic document such as a postscript of forged data to the electronic document and deletion of the electronic document and exhibit a forgery and alteration prevention function efficiently. SOLUTION: The electronic document is input by an input-output part 11 and an electronic signature data is generated by an electronic signature section 15. The electronic signature data is stored in a secret information storage 14 as secret information. Moreover, a hash value is computed from the electronic document and the electronic signature data by a hash value calculation unit 13. The hash value is recorded on the electronic document and stored in an electronic document storage 12. When the postscript is performed to the electronic document, the hash value is computed by the hash value calculation unit 13 from a previous hash value which has been taken out from the electronic document storage 12, an input postscript data, and the electronic signature data read from the secret information storage 14. The hash value and the postscript data are recorded on the electronic document and stored in the electronic document storage 12. COPYRIGHT: (C)2009,JPO&INPIT |
