Blurry ORAM: A Multi Client Oblivious Storage Architecture
Since the development of tree based Oblivious RAM by Shi et al. (Asiacrypt '11) it has become apparent that privacy preserving outsourced storage can be practical. Although most current constructions follow a client server model, in many applications it is desirable to share data between different clients, in a way that hides the access patterns, not only from the server, but also between the clients. In this work, we introduce BlurryORAM, an extension of Path ORAM that allows for oblivious sharing of data in the multi client setting, so that accesses can be hidden from the server and other clients. Our construction follows the design of Path ORAM as closely as possible in order to benefit from its performance as well as security. We prove our construction secure in a setting where the clients are semi honest, do not trust each other but try to learn the access patterns of each other.
IACR Cryptol. ePrint Arch.