From the International Digital Publishing Forum website (Request for Comments: Use Cases & Requirements for Lightweight Content Protection for EPUB):
The IDPF on May 18, 2012 published a draft of use cases and requirements for lightweight content protection technology for EPUB, available at: http://idpf.org/epub-content-protection. Comments from members and other interested parties are requested by Friday, June 8. Comments are particularly solicited regarding the priority of this activity versus other potential IDPF-mediated projects. Also requested are comments on any additional high priority use cases and requirements not encompassed in this initial straw-man document, and regarding the overall desirability of a solution embodying the proposed requirements, or any standardized solution in this area.The document describes requirements for a potential content protection scheme for EPUB. It outlines what would be a “lightweight” scheme, occupying a middle ground between strong DRM and DRM-free. This would enable sharing with or without watermarking, but, unlike watermarking alone, cracks would be considered definitively illegal. As well, the proposed scheme incorporates configurable passwords (including the option of no password at all); it can be used to discourage “over-sharing” by requiring passwords that contain personal information, such as an email address or credit card number. The use of encryption also serves to enable limits on modification, copying, and printing of content in a manner similar to the encryption technology incorporated in PDF. It would also support lending models via usage durations. Other aspects that would make the scheme “lightweight” include not requiring network connectivity (i.e. no “phoning home”) and trading off less stringent security for lower implementation cost and complexity.