For example, you can use a policy to enforce a setting so that only particular users can sign a document or you can enforce the use of a specific Hash Algorithm. You can also trigger certain operations to take place on satisfying the conditions set within a policy. For example you can trigger an encryption operation on a document, if that document has been signed using a particular certificate. Polices can also be created for Certificates. These are textual information that can be attached to a certificate to identify the use or define the limits of use of a certificate.
Certificates are useful because they attest to the identity of the user or organization.
This eliminates the hassle of entering a user name and password multiple times. In order to send someone an encrypted message, you must have the recipient s certificate. Certificates provide stronger and more reliable authentication over traditional methods. Traditional methods include entering user names and passwords 5. Because certificates are public information, they can travel across the Internet, Extranet and Intranet without any security risks.