OFFICIAL KEY CODER FOR VERIFYING AUTHENTICITY OF DOCUMENT FOR THIRD PARTY AND VERIFICATION OF AUTHENTICITY OF DOCUMENT FOR THIRD PARTY USING THE SAME

摘要

PURPOSE: To provide authentication confirmation service without the need to maintain a large-volume data base by using open key ciphering technology. CONSTITUTION: A user 12 when participating in the service of an authentication source 10 is given a box 13 containing E2 of a key pair keys E2 D2 and a box 13 including boxes 14 and 18, and the box 13 is locked with a key 100 and D2 and unlocked with E2 . A box 16 has a key 16 indicating ciphering and deciphering with the key pair E2 D2 , the box 18 has a key 20 locked with the ciphering key D1 of a key pair E1 D1 , and the key E1 is held secret by the autheotication source 10 and includes an authentication document 22 and a deciphering key D2 24 for opening the box. The user 12 puts original information in the box 14, locks the box with E2 , and provides the boxes 14 and 18 for the authentication authentication service 26. The authentication service 26 is supplied with a common deciphering key D1 18 common to all boxes 18 from the authentication source 10. The box 18 can be unlocked (deciphered) with one dedphering key 28 of an unasslgned key pair, so the authentication service 26 needs not maintain a large-volume data base.