RMS stands for Rights Management Services.
RMS historically was only available on corporate networks and required the appropriate infrastructure to support it.
Yesterday Microsoft announced free RMS is now available for individuals. The best part is that it is free.
Now anyone can protects their own files with encryption through RMS.
How RMS Works
(from this link: http://technet.microsoft.com/en-us/magazine/2006.10.howitworks.aspx)
RMS is involved in three areas to ensure proper utilization: the actual creation of rights-protected resources, licensing and distributing these rights-protected resources, and decryption and usage of rights-protected resources. A trusted entity (one that has been granted access to make use of RMS) can create resources that are protected. When a resource has been protected, an XrML certificate identifies who is allowed access and what usage requirements are imposed on the resource.
The RMS server will issue a publishing license that delineates who is allowed to access the resource. Once this is done, the protected resource can be sent. When a trusted entity, say a user, wants to access a resource, the user will be validated by the RMS server which holds the public key for the encrypted resource and will issue a use license to the user. This use license specifies how the resource can be used and actions that can be taken with it. So these licenses are employed as the actual control mechanisms. The publishing license is created when a document is RMS-enabled and has been encrypted. The use license is required when a document is consumed.
To learn more about the free RMS for individuals and sign up visit: