The war on copying

摘要

The communications industry is ready for an infusion of data, such as digital video, to drive it to recovery, but music, video, and other digital-content owners continue to keep a tight rein on their growing mass of IP (intellectual property) while waiting for a secure DRM (digital-rights-management) scheme to materialize. The complexity of DRM, however, makes it a nontrivial addition to a system, especially a consumer device with a low cost threshold. Several standards are under development to define how to encrypt material and distribute it over public networks. Rather than define the policies themselves, they define a foundation framework that can support a variety of DRM policies. For example, the ISMA (Internet Streaming Media Alliance) 1.0 Encryption and Authentication spec, scheduled for approval this month, describes how to apply the Advanced Encryption Standard (AES) to content and packetize content for distribution in such a way as to prevent a late packet from disrupting the stream.