Understanding Information Rights Management

New to Outlook 2003, Information Rights Management (IRM) enables you to secure a message, including any attachments, to prevent the recipient from printing, forwarding, or copying the message or attachment. The recipient can open the message only after she confirms her identity by logging on to her Passport account.

Although there are similarities between digital signatures and IRM, they're two distinct methods you can use to secure your messages. You can digitally sign and encrypt IRM-protected messages.

A digital signature is used to prove you are the person sending the message; encryption prevents someone who doesn't have your private key from opening the message.

IRM ensures the confidentiality of the message and attached documents by preventing the recipient from printing, forwarding, or copying a message that's sent with IRM enabled.

Office 2003 applications that support IRM are Word, PowerPoint, and Excel. Microsoft will release a server add-on for corporations that want to deploy IRM internally. Anyone with a .NET Passport account can control permissions for their messages and read restricted messages or documents. Other documents are partially restricted in that they're restricted when attached to a message that's protected by IRM. The File and Save dialogs are disabled, along with Print and Forward. However, you can save the attachments to your drive and use them as you normally would. When you send a message or document using restricted permissions to someone who doesn't have Office 2003, he'll have to install an Internet Explorer add-in to read the message or view the attachment.

Don't confuse using document protection with IRM. Both can prevent others from using the document, but each method has advantages and disadvantages.

• Document protection uses a password to protect the document from prying eyes. Anyone who knows the password can open the document and you can't control what happens to it.

• IRM protects the document using a digital certificate and only those people you give permission to can open the document. You retain complete control over the document, including whether someone can edit, copy, or print it. In the case of email, you can prevent others from forwarding the message.

A popular trick to reduce mailbox size is to remove large attachments from messages and then save the message. However, when a message has restricted permissions assigned, you're unable to remove the attachments and save the message. If you need to keep the message, you'll also have to keep the attachment with it.