DNS article
Document DRM: Replacing Encryption as the Standard for Document
Protection
http://www.infosecwriters.com/text_resources/pdf/Document_DRM_vs_encryption.pdf
http://www.securitytechnet.com/resource/security/application/Document_DRM_vs_encryption.pdf
http://security.ittoolbox.com/white-papers/Why-Document-DRM-will-Replacing-Encryption-as-the-Standard-for-Document-Protection-4551
Layered Approach to Security is Dead: Long Live the layered
Approach
http://www.net-security.org/article.php?id=668
DRM and the Enterprise
http://security.ittoolbox.com/documents/Peer-Publishing/drm-and-the-enterprise-4025
Sharing Documents in an Environment of Trust