An engineer is working on the implementation of digital certificates for new critical web applications. One of the requirements is that the https connection must be validated and protected against…

X.509 is the internationally recognized standard that defines the format of public key certificates used to secure communications over the internet, including HTTPS, by binding a public key to an entity and validating its identity through a trusted Certificate Authority (CA). This certificate format is essential for establishing trust and preventing impersonation.

While a private CA issues X.509 certificates, using a private CA for an externally exposed server would typically require clients to explicitly trust that private CA, which is not practical for public web applications.

SSLv3 is an outdated and insecure protocol for establishing secure connections, not a certificate format.

TLS 1.1 is also an older, less secure version of the Transport Layer Security (TLS) protocol, which is used to negotiate the secure connection, not a certificate itself.