Title: Securing Bulk Content Almost for Free
Authors: John Byers, Mei Chin Cheng, Jeffrey Considine, Gene Itkis, Alex Yeung
Date: January 22, 2002

Abstract:

Content providers often consider the costs of security to be greater
than the losses they might incur without it; many view ``casual
piracy'' as their main concern.  Our goal is to provide a low cost
defense against such attacks while maintaining rigorous security
guarantees.  Our defense is integrated with and leverages fast forward
error correcting codes, such as Tornado codes, which are widely used
to facilitate reliable delivery of rich content.  We tune one such
family of codes - while preserving their original desirable properties
- to guarantee that none of the original content can be recovered
whenever a key subset of encoded packets is missing.  Ultimately we
encrypt only these key codewords (only 4% of all transmissions),
making the security overhead negligible.