Public Key Infrastructure (PKI) was once touted as the answer to all security evils. Of course there's no such “Silver Bullet” as effective security requires people, processes and technology to work in union based on a meaningful security policy.
When implemented in the appropriate manner PKI can be used to solve the following problems involving Confidentiality, Integrity and Authentication:
Many technical people have "dabbled" with PKI but failed to grasp the principles upon which such solutions are based.
Click here to view the recording of a recent webcast that will teach you (in 40 minutes) how PKI works.