Public Key Infrastructure (PKI) refers to the technical mechanisms, procedures and policies that collectively provide a framework for addressing the previously illustrated fundamentals of security - authentication, confidentiality, integrity, non-repudiation and access control.
PKI enables people and businesses to utilise a number of secure Internet applications. For example, secure and legally binding emails and Internet based transactions, and services delivery can all be achieved through the use of PKI.
PKI utilises two core elements; Public Key Cryptography and Certification Authorities.
The benefits of PKI are delivered through the use of Public Key Cryptography. A core aspect of Public Key Cryptography is the encryption and decryption of digital data.
Encryption is the conversion of data into seemingly random, incomprehensible data. Its meaningless form ensures that it remains unintelligible to everyone for whom it is not intended, even if the intended have access to the encrypted data.
The only way to transform the data back into intelligible form is to reverse the encryption (known as decryption). Public Key Cryptography encryption and decryption is performed with Public and Private Keys.