Since many systems interact with each other to achieve their business goals, we often feel the obligation to interact with services exposed by others. Also, when security needs play an important role, we must verify that the information we receive has been sent from whom we expected, and it has come without being altered. It is here where digital signatures will play an important role and help us meet this need.

Also, we may sometimes need to encrypt the message body to prevent it from being read if intercepted by unwanted persons. It is here where we can make use of Secure/Multipurpose Internet Mail Extensions, or the S/MIME standard, which is commonly used in the world of e-mail for public keys (http://en.wikipedia.org/wiki/Public_key), encryption (http://en.wikipedia.org/wiki/Encryption), and signing (http://en.wikipedia.org/wiki/Digital_signature) of MIME data (http://en.wikipedia.org/wiki/MIME), and which also offers the ability...