Cost-Effective Authentic and Anonymous Data Sharing with Forward Security

Computer Engineering

Data sharing has is not easier with the advances of cloud computing, and an accurate analysis on the shared data provides more benefits to both the society and individuals. Data sharing with a large number of participants must take into account several issues, including efficiency, data integrity and privacy of data owner. Ring signature is a promising candidate to construct an anonymous and authentic data sharing system. Ring signature showing possibility of achievement to construct an anonymous and authentic data sharing system. It allows a data owner to anonymously authenticate his data which can be put into the cloud for storage or analysis purpose. Yet the costly certificate verification in the traditional public key infrastructure (PKI setting becomes a waist for this solution to be scalable. Identity-based (ID-based) ring signature, which eliminates the process of certificate verification, can be used instead of traditional public key infrastructure. In this paper, we further enhance the security of ID-based ring signature by providing forward security: If a secret key of any user has been dedicated, all previous generated signatures that include this user still remain valid. This property is especially important to any large scale data sharing system, as it is impossible to ask all data owners to reauthenticate their data even if a secret key of one single user has been dedicated. We provide a concrete and efficient instantiation of our scheme, prove its security and provide an implementation to show its practicality.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.