In the US, insults are not something for which you can be prosecuted. Calling someone a son of a bitch is not defamatory. No one believes you are really the child of a dog. So that is an opinion. Defamation requires a false factual statement. Truth is a complete defense.
What is Public Key Infrastructure (PKI)? Public Key Infrastructure (PKI) is a set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates. In cryptography, a PKI is an arrangement that binds public keys with respective user identities by means of a certificate authority (CA). Wikipedia.org
How PKI Works. A PKI is based on certificates. A certificate is a digitally signed statement containing a public key and the name of the subject. There can be multiple types of names in the certificate by which the subject is known, such as a directory name, e-mail name, and Domain Name Service (DNS) name. certificate is a digitally signed statement containing a public key and the name of the subject. There can be multiple types of names in the certificate by which the subject is known, such as a directory name, e-mail name, and Domain Name Service (DNS) name.