Encrypted Searchable Storage of RFID Tracking Data

Companies can optimize their supply chain if they exchange item-level data, i.e. item-specific data gathered with the help of Radio Frequency Identification or 2D bar codes. Data can either be distributed over the repositories of each company or stored in a central repository. The distributed approach requires "discovering" the repositories which contain data about the queried item. Thus, data access is slow. The central approach does not require discovery, but the data owner has to relinquish access control to the repository provider. Both approaches are not satisfactory. In this paper we present an encryption scheme for exchanging item-level data by storing it in a central repository. It allows the data owner to enforce access control on an item-level by managing the corresponding keys. Furthermore, data remains confidential even against the repository provider. Thus we eliminate the main problem of the central approach. We provide formal proofs that the proposed encryption scheme is secure. Then, we evaluate the encryption scheme with databases containing up to 50 million tuples. Results show that the encryption scheme is fast, scalable and that it can be parallelized very efficiently. Our encryption scheme thereby reconciles the conflict between security and performance in item-level data repositories.