PIR-Writing Protocol That Supports Information Share

The rapid development of the Internet and the progress of network facilities, cloud database services are very popular with the web users, which allows users to retrieve, update and delete the records of the cloud database. However, these users of such services do not always trust the cloud storage provider to keep their privacy. Therefore, neither the user´s database information nor the access pattern is revealed to the storage server. PIR-Writing can protect the user´s update privacy from the storage server. In this paper, we propose a new PIR-Writing scheme which support cloud database information sharing by multiple users. Especially, our protocol keep the communication cost o(logn) which is lowest until now. Further more, it can improve the computation cost of PIR-Writing from o(nlogn+ln) to o(1). Meantime, our scheme has a good availability and security.