An Efficient Universal Designated Verifier Signature Scheme for Non-Transferable Data Sharing in Clouds

Abstract

In the cloud data sharing environments, a universal designated verifier signature (UDVS) scheme is a better choice to protect the right and privacy of data owner who has a valid signature on his personal data, say medical records. In particular, such a scheme provides a non-transferable data sharing mechanism for the data owner to convince an intended cloud data user of the validity of his data. Also, the designated cloud data user is unable to further persuade any third party of his conviction, so as to prohibit designated cloud users from arbitrarily disseminating downloaded information. In this paper, we propose a new efficient UDVS scheme for non-transferable data sharing in clouds. A data owner can upload his personal data with corresponding signatures to cloud servers and only the designated data user can download it and verify its validity without further transferring it to irrelevant users. The proposed scheme is based on the well-known computational Diffie-Hellman assumption and is proved secure against adaptively chosen-message attacks in the random oracle model. The efficiency comparison also reveals that the proposed UDVS scheme has lower computational costs, which helps with practical implementation.