| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an information assurance system and a context information assurance device assuring operation history information for information, without disclosing data on the information. <P>SOLUTION: An electronic conference system 100 issues assurance request by generating context identification information based on a random sequence and an object ID from a start time to an end time of a conference by a conference system controller 11, for an object such as a user operating the electronic conference system 100 and a multifunction machine 102 and an electronic document used in the operation. A context assurance server 200 generates the random sequence in the same time for the assurance request, and generates context identification information for collation, based on the random sequence and the object ID included in the assurance request. Context assurance information with a time stamp and a digital certificate is stored in a context storage server 101 generating them, when the context identification information is same as the context identification information for the collation. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
