We present a radically new approach to fully homomorphic encryption (FHE) that dramatically improves performance and bases security on weaker assumptions. A central conceptual contribution in our work is a new way of constructing leveled fully homomorphic encryption schemes (capable of evaluating arbitrary polynomial-size circuits), without Gentry’s bootstrapping procedure. Specifically, we off...

The security of most public-key encryption schemes relies on the hardness of the learning with errors (LWE) problem – an average-case hard lattice problem introduced by Regev ([Reg05]). While LWE has been proved to be as hard as quantumly approximating the so-called Short Independent Vectors Problem, the parameters used in the proof are not suitable for practical reasons. It makes difficult to ...

PURPOSE This study compared a new contact lens rewetting drop containing both carboxymethylcellulose and hyaluronic acid (CMC-HA) with a standard drop containing carboxymethylcellulose only (CMC). Symptoms of discomfort typical in lens wear and lid wiper epitheliopathy (LWE) were assessed over a 3-month period in a diverse sample of contact lens wearers. METHODS Adapted daily-wear contact len...

This paper, examining the hardness of the search LWE problem, is a refined continuation of previous works including (Lindner-Peikert 2011, Liu-Nguyen 2013, Aono et al. 2013) using lattice reduction and lattice vector enumeration. We adopt the attack to the LWE using discrete Gaussian distribution, and propose a new bounding method named band pruning in lattice enumeration. We update the securit...

Two main computational problems serve as security foundations of current fully homomorphic encryption schemes: Regev’s Learning With Errors problem (LWE) and HowgraveGraham’s Approximate Greatest Common Divisor problem (AGCD). Our first contribution is a reduction from LWE to AGCD. As a second contribution, we describe a new AGCD-based fully homomorphic encryption scheme, which outperforms all ...

A multiparty computation protocol is said to be adaptively secure if it retains its security in the presence of an adversary who can adaptively corrupt participants as the protocol proceeds. This is in contrast to a static corruption model where the adversary is forced to choose which participants to corrupt before the protocol begins. A central tool for constructing adaptively secure protocols...

We conduct a study of public-key cryptosystems based on variants of the Learning Parity with Noise (LPN) problem. The main LPN variant in consideration was introduced by Alekhnovich (FOCS 2003), and we describe several improvements to the originally proposed scheme, inspired by similar existing variants of Regev’s LWE-based cryptosystem. To achieve further efficiency, we propose the first publi...