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
History of the X.509 Standard. PKI is governed by a the X.509 standard published by the International Telecommunications Union (ITU-T) (http://www.itu.int/ITU-T/) as part of the X.500 series of standards governing directory services.