On controlled sharing of virtual goods

Digital Rights Management Systems aim at protecting copyrighted virtual goods against illegal distribution and usage. They enable content owners to formulate usage policies, which are supposed to be enforced on consumers' devices. However, prevailing systems have two shortcomings. They give little attention to consumers' expectations by being too restrictive and they fail at protecting digital content, since they build up their protection techniques on unreliable basis, e.g., obscurity methods. This paper presents an approach that overcomes these two shortcomings. It supports the transfer of digital content between users and devices and, thus, provides more flexibility. This transfer is based on mutual consent between a consumer and a content provider at the time of purchase and happens in a preconcerted and reliable way. In addition, the transfer between users does not require any interaction with the content provider at the time of transfer.