Digital certificate refers to a kind of digital authentication that identifies the identity information of all parties in Internet communication, and people can use it to identify each other's identity on the Internet.

Therefore, digital certificates are also called digital identity certificates. Digital certificate can ensure the integrity and security of information and data for network users in computer network communication in the form of encryption or decryption.

The basic working principle of digital certificate is mainly embodied in:

First, before sending information, the sender needs to contact the receiver and encrypt the information with the public key. The information is always in the ciphertext state during transmission, including the encrypted information received by the receiver, which ensures the uniqueness of information transmission. If the information is stolen or intercepted, the data can be interpreted only by using the private key of the receiver, but the data cannot be changed, which is also conducive to ensuring the integrity and security of the information.

Second, the data signature of digital certificate is similar to the encryption process. After the data is encrypted, only the receiver can open or change the data information, add its own signature and then transmit it to the sender. The receiver's private key is unique and private, which also ensures the authenticity and reliability of the signature, thus ensuring the security of information.