ABSTRACT
In this chapter, a brief review of the state of the art in the application of security systems for electronic commerce is presented. In particular, the chapter deals with the following themes: definition of security services in open networks; security functions and their possible locations in various layers of the distribution network; mechanisms to implement security services; certification of the participants; and the management of the encryption keys. Some potential threats to security are highlighted, particularly as they relate to cracks in the protection walls of cryptography.
