US 2003/0159048 A1 · Time stamping system for electronic documents and program medium for the same

Abstract

Object: To provide a time stamping system for electronic documents making it possible to easily provide a time stamp certifying date and time of a document prepared with general purpose document preparation software and also to easily and accurately verify the time data and a program medium for the same. Solution: The electronic document preparing organization 20 at a client site has a first document preparation terminal device 30 and a second document preparation terminal device 40. When the document preparation terminal device 30 transmits the prepared document and a time stamp request message 31 to the time stamp issuing server 12, and time stamp issuing server 12 assigns electronic signatures with the signature generation secret keys Ks1, Ks2 and returns the data to the document preparation terminal device 30. The document preparation terminal device 40 a document file with the time stamp received from the terminal device 30 assigned therein and a time stamp verification request message 41 to the time stamp verification server 13. The time stamp verification server 13 verifies the time stamp with the signature verification secret key Kv2, and returns a result of the verification. The terminal device 30 and the terminal device 40 can verify the signature and the result of verification respectively with the signature verification public key Kv1.

Claims10

Dependent claims

A time stamping system for electronic documents based on the configuration where a digest value generated based on an electronic document prepared by a client electronic document preparation terminal device with electronic document preparation software incorporated therein is transmitted to an external organization device and the external organization device assigns the time of receipt and an electronic signature to the digest value and returns it to the client, wherein the client electronic document preparation terminal device comprises:

an electronic document reading means for reading an electronic document prepared by the electronic document preparation software;
a digest value computing means for computing a digest value including a hash value as a unidirectional function value based on a read document;
a transmitting means for correlating the digest value to an ID number of the client electronic document preparation terminal device and transmitting the digest value and the ID number to the external organization device;
a receiving means for receiving an electronic certificate transmitted thereto from the external organization device with the term of receipt and the electronic signature assigned to the digest value received by the external organization device as well as to the ID number of the client electronic document preparation terminal device;
and
an electronic certificate inserting and writing means for writing the received electronic certificate in the electronic document to be time-stamped stores in the client electronic document preparation terminal device.

3 more elements

A computer-readable program medium for time-stamping electronic documents with a program recorded therein, said program enabling a computer to realize a function for sending a digest value for an electronic document prepared by a client electronic document preparation terminal device with electronic document preparation software incorporated therein to an external organization device and a function for receiving the electronic certificate returned from the external organization device with the time of receipt and an electronic signature assigned thereby to the digest value, and inserting and writing the electronic certificate in the electronic document to be time-stamped stored in the client electronic document preparation terminal device, wherein said client electronic document preparation terminal device has a program recorded therein for enabling a computer to realize:

an electronic document reading function for reading electronic documents prepared by the electronic document preparation software;
a digest value computing function for computing a digest value from the read electronic document alkoxysilane a unidirectional function value thereof;
a transmitting function for correlating the digest value to an ID number of the client electronic document preparation terminal device and transmitting the digest value and ID number correlated to each other to the external organization device;
a receiving function for receiving the electronic certificate returned from the external organization device with a time stamp and an electronic signature assigned thereto;
and
an electronic certificate writing function for writing the returned electronic certificate in an electronic document to be time-stamped prepared by the client electronic document preparation terminal device.

3 more elements

Dependencies are inferred from the claim text.

Time stamping system for electronic documents and program medium for the same

Life of this patent

Time stamping system for electronic documents and program medium for the same

Life of this patent

Abstract

Claims10