1. This interface specification adopts the HTTPS communication protocol. It is clear that the request header and return data use JSON format data messages, and it is clear that the message uses the HMAC-SM3 signature algorithm for signature calculation. 2. This interface specification clarifies the identity authentication method for application system interface calls, and clarifies that identity authentication uses the HMAC-SM3 algorithm to perform signature calculation on request data. 3. This interface specification defines the interface services for practicing certificates in the medical industry, and uses different CA vendors to provide common service interfaces for CA certification for medical institutions, including electronic signatures, timestamps, QR code scan signatures, etc. 4. This standard follows the signature service interface standardized by "GB/T38540-2020 Information Security Technology Secure Electronic Signature and Password Technical Specifications".