Proxy re-designated verifier signature and its applications

摘要

>With the development of cloud computing, vast amounts of data are stored in a cloud. Some stored contents may be shared with other people. For a content consumer, it is crucial to identify the owners of some contents. However, for a content owner, it is usually better not to leave evidences on sharing some contents. Considering this requirement, we propose a new cryptographic primitive based on designated verifier signatures (DVSs) to enable efficient sharing of sensitive contents in a cloud. With the primitive, a content owner can store a sharable content in a cloud. On request of a content consumer, the content owner can produce a re-signing key for a cloud server with which the cloud server produces a customised DVS of the content for the content consumer. The customised DVS can be verified by the consumer, and cannot be transferred to any third party for a proof of source. When the content owner is under investigation, they can always deny their sharing of sensitive contents facing evidences collected from a receiver.