Efficient oblivious transfer construction via multiple bits dual-mode cryptosystem for secure selection in the cloud

Abstract

ABSTRACTCloud computing is a promising paradigm to provide flexible and reliable services. Nevertheless, concern and anxiety about data security and tenants’ privacy are still a major barrier for the popularity of cloud computing. Oblivious transfer (OT) is a cryptographic primitive that enables a client to selectively retrieve data in a privacy-preserving manner. It can be used to construct high-level protocols enabling applications in the cloud-computing paradigm. Technically, it has been proven that OT protocols can be constructed using a CPA-secure public-key encryption scheme. Along these lines, Peikert et al. formulated a dual-mode cryptosystem on which they constructed a single-bit OT scheme. Obviously, it has deficiencies in performance, which makes it unqualified for use in cloud-computing scenarios. This paper aims at providing an efficient multi-bit OT scheme for secure cloud applications. We first propose a multi-bit dual-mode cryptosystem based on the learning with errors (LWE) problem. Based on this multi-bit dual-mode cryptosystem, we construct a multi-bit OT. We present details of the OT construction together with security analysis of our scheme, and finally provide an example of how it can be used in specific application scenarios.