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
Definition - What does Public Key Infrastructure (PKI) mean? A public key infrastructure (PKI) allows users of the Internet and other public networks to engage in secure communication, data exchange and money exchange. This is done through public and private cryptographic key pairs provided by a certificate authority.