Arx: An Encrypted Database using Semantically Secure Encryption Rishabh Poddar Tobias Boelter Raluca Ada Popa UC Berkeley UC Berkeley UC Berkeley
[email protected] [email protected] [email protected] ABSTRACT some of which are property-preserving by design (denoted In recent years, encrypted databases have emerged as a PPE schemes), e.g., order-preserving encryption (OPE) [8, promising direction that provides data confidentiality with- 9, 71] or deterministic encryption (DET). OPE and DET out sacrificing functionality: queries are executed on en- are designed to reveal the order and the equality relation crypted data. However, many practical proposals rely on a between data items, respectively, to enable fast order and set of weak encryption schemes that have been shown to leak equality operations. However, while these PPE schemes con- sensitive data. In this paper, we propose Arx, a practical fer protection in some specific settings, a series of recent and functionally rich database system that encrypts the data attacks [26, 37, 61] have shown that given certain auxiliary only with semantically secure encryption schemes. We show information, an attacker can extract significant sensitive in- that Arx supports real applications such as ShareLaTeX with formation from the order and equality relations revealed by a modest performance overhead. these schemes. These works demonstrate offline attacks in which the attacker steals a PPE-encrypted database and PVLDB Reference Format: analyzes it offline. Rishabh Poddar, Tobias Boelter, and Raluca Ada Popa. Arx: Leakage from queries refers to what an (online) attacker An Encrypted Database using Semantically Secure Encryption. PVLDB, 12(11): 1664-1678, 2019.