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
Public Key Infrastructure. A PKI: 1. binds public keys to entities. 2. enables other entities to verify public key bindings. 3. provides services for management of keys in a distributed system. Goal: protect and distribute information that is needed in a widely. distributed environment, where the users, resources and stake-holders.