The CA certificate is actually an authentication of the user's public key issued by a certificate issuing authority (CA).

The contents of the certificate include: electronic visa authority information, public key user information, public key, signature and validity period of the authority, etc. The format and verification method of the certificate generally follow the X.509 international standard.

Certificate Authority (CA, Certificate Authority) is the organization that issues digital certificates. It is an authoritative organization responsible for issuing and managing digital certificates. As a trusted third party in e-commerce transactions, it assumes the responsibility of verifying the legality of public keys in the public key system.

Extended information

The digital certificate appends the user information and the signature of the CA after the user's public key. The public key is one part of the key pair and the other part is the private key. The public key is made public and anyone can use it. Only you know the private key. Information encrypted by a public key can only be decrypted by its corresponding private key.

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

Baidu Encyclopedia-CA Certification