The author indicates that the digital certificate has expired and needs to be updated; It cannot be used after the extension, and the digital certificate needs to be uninstalled and regenerated.

Shanghai CA follows the requirements of People's Republic of China (PRC) Electronic Signature Law and related laws and regulations, and provides digital identity authentication and management services for institutions with electronic authentication, digital certificate and electronic signature/seal as their core. Personal digital certificate issued by CA is used to identify the digital identity of individuals in the network. Digital certificate is based on cryptography, using digital signature, digital envelope, time stamp service and other technologies to establish an effective trust mechanism on the Internet. It mainly includes the information of the certificate owner, the public key of the certificate owner and the signature of the certificate issuing authority. Users use this certificate to identify the digital identity of the certificate holder on the Internet, thus ensuring the security and integrity of information in the process of Internet transmission.