The certificate includes the name and relevant information of the applicant, the key of the applicant, the digital signature of the certificate issuing authority and the validity period of the certificate. Function: code signing certificate is a digital certificate issued by CA Center to software developers. If the software developer wants to publish the software through the network, he can first sign the software with code signing certificate. In this way, when users download software from the network, they will get a prompt from code signing, so that they can determine the true source of the software; The software has not been modified or destroyed from signing to downloading. The use of code signing certificate, for users, can make users clearly understand the source and reliability of software, and enhance their determination to obtain software through the network. In case users download harmful software, they can also trace the source of the software according to the certificate.