What is root certificate and its role

The root certificate is a digital certificate, which is used to build the trust chain in the public key infrastructure (PKI) system. The root certificate is the highest level certificate in PKI and is issued by a trusted certificate authority (CA). It is used to verify the authenticity and validity of other certificates.

The root certificate contains a digital signature, as well as the public key and identification information associated with it. This digital signature is generated by the private key of the CA to protect the integrity and tamper resistance of the root certificate. This means that only the institution holding the private key corresponding to the CA public key can issue a valid root certificate. In the PKI system, the root certificate acts like a trust anchor. They are used as a trusted source for verifying other certificates to ensure the security and reliability of digital communication. When the client communicates securely with the server, the client verifies the validity of the server certificate and checks whether it is signed by a trusted root certificate.

In a word, the root certificate is one of the most important certificates in PKI, which is used to establish the trust chain and ensure the security of digital communication.