Certificate Issuance
The center receives and verifies applications for digital certificates from users (including subordinate certification centers and end users) and will apply for them. The content will be recorded, and whether to accept the digital certificate application will be determined based on the content of the application. If the center accepts the digital certificate application, it further determines what type of certificate will be issued to the user.
After the new certificate is signed with the private key of the certification center, it is sent to the directory server for users to download and query. In order to ensure the integrity of the message, all response information returned to the user must be signed by the certification authority.
Certificate Update
The certification center can regularly update the certificates of all users, or update the user's certificate based on the user's request.
Certificate query
Certificate query can be divided into two categories. One is the query of certificate application. The certification center returns the current user certificate application according to the user's query request. The second is the query of user certificates. This type of query is completed by the directory server, and the directory server returns the appropriate certificate according to the user's request.
Invalidation of certificates
When the user's private key needs to be invalidated due to leakage or other reasons, the user needs to submit a request to the certification center for the invalidation of the certificate. The center determines whether to invalidate the certificate based on the user's request. Another situation where a certificate becomes invalid is that the certificate has expired and the certification center automatically invalidates the certificate. The certification center accomplishes the above functions by maintaining a certificate revocation list.
Certificate Archiving
The certificate has a certain validity period. After the validity period, the certificate will be invalid, but we cannot simply discard the invalid certificate, because sometimes we It may be necessary to verify the digital signature generated during a previous transaction. In this case, we need to query the invalid certificate. Based on such considerations, the certification center should also have the function of managing invalidated certificates and invalidated private keys.
In general, the security solution based on the certification center should well solve the problems of online user identity authentication and secure information transmission.
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