What is a ca digital certificate?

CA certificate is actually issued by the certificate visa authority (CA) of the user's public key authentication.

The content of the certificate includes: information on the electronic visa authority, public key user information, public key, the signature of the authority and the validity period and so on. Certificate format and validation methods generally follow the X.509 international standard.

Certificate Authority (CA, Certificate Authority) that is the issuance of digital certificates. It is the authority responsible for issuing and managing digital certificates, and as a trusted third party in e-commerce transactions, it bears the responsibility for the legitimacy test of the public key in the public key system.

Expanded Information

Digital certificates attach user information and the CA's signature to the user's public key. The public key is part of the key pair and the other part is the private key. The public key is public and can be used by anyone. The private key is known only to you. Information encrypted by the public key can only be decrypted by the private key that corresponds to it.

To ensure that only a certain person can read his or her message, the sender encrypts the message with the recipient's public key; the recipient can then decrypt the message with his or her private key. Similarly, to verify the sender's identity, the sender signs the letter with his private key; the recipient can verify the signature with the sender's public key to confirm the sender's identity.

Baidu Encyclopedia-CA Authentication