Components of an Exchange 2003 Message Security System

In a fully deployed Exchange Server 2003-based message security system, there are three technologies that make up the complete solution. These technologies are:

• Exchange Server 2003

• E-mail client

• PKI

The following figure shows a conceptual drawing of how these three components fit together.

Technologies that make up an Exchange Server 2003-based message security system

As this figure shows, Exchange 2003 primarily interacts with the e-mail client, and the e-mail client primarily interacts with the PKI. All three parts are required and work together to form the complete system. Although this modular design can initially seem complicated, it provides flexibility in the specific technologies that customers can choose to deploy for a more secure message solution.

This modular design is possible because of support for S/MIME in Exchange 2003. Exchange 2003 takes advantage of the wide support that S/MIME has and interacts with products based on their support of this standard. Exchange uses the advantages that these technologies have from supporting the S/MIME standard.

In addition, Exchange supports standards-based message security through its existing capabilities. For example, Exchange 2003 supports S/MIME e-mail clients through its existing support for e-mail client protocols. Any e-mail client that can connect with Exchange 2003 and also supports S/MIME is a viable client for a message security system.

Because S/MIME is a standard, those same mail clients that support S/MIME can use any PKI that conforms to the S/MIME standard. Any PKI that supports a chosen mail client can inherently be used in an Exchange 2003 message security system.

This standards-based support also makes it possible for users of Exchange 2003 to use message security features with users of other mail systems, if both users' mail clients are using compatible versions of S/MIME.

S/MIME support in Exchange 2003 provides customers a higher degree of flexibility and interoperability in the specific products that make up the total message security solution.

To understand the options available in an Exchange 2003 S/MIME solution, it helps to discuss the specific options available for the two additional components that make up an Exchange 2003 solution: e-mail clients and PKI.