As security has become an essential need for any system to guarantee safe communication among users, the
need for a technique to secure those channels became a demand. Public Key Infrastructure offers many ways to
secure communications depending on the type or level of security needed. The paper has gone through the main
components of a PKI and what operations they are assigned to. There are many infrastructures in the area and
the paper discussed two of the main PKIs: PGP and X.509 besides a brief overview of the two new PKIs: WPKI
and LPKI where they match the needs of the current devices and technologies. As in anything related to using a
technique, PKI has its own risks when being used and those risks were discussed in the paper. In the end, the
authors hope they have made a contribution by going through the main aspects of an important security application.