Electronic signature is data in electronic form, which is associated with data message (electronic document, electronic information) to identify the identity of the signer and show that the signer approves the content of the data message. Electronic signature is an online identity authentication system based on international PKI standard, and digital certificate is equivalent to online identity card. Through the third-party authoritative authentication of digital signature, it can effectively authenticate online identity, help each subject identify each other's identity and show their own identity, and has the functions of authenticity and anti-denial.

Different from physical ID cards, digital certificates also have the characteristics of security, confidentiality and tamper resistance, which can effectively protect and securely transmit information transmitted by enterprises on the Internet.

The system using digital certificate needs to install the root certificate provided by the certification authority, and the user's digital certificate is stored in the corresponding media. If a certificate is used, the user will use the certificate media and user password according to the system prompt.

In general, the system will automatically prompt the user to show the digital certificate or insert the certificate medium (IC card or key). After the user inserts the certificate media, the system will ask the user to enter the password. At this point, the user needs to enter the password obtained when applying for the certificate. After the password is verified correctly, the system will automatically call the digital certificate for related operations.