Abstract The ring learning with errors (RLWE) problem can be used to construct efficient post-quantum public key encryption schemes. An error distribution, normally a Gaussian-like is involved in the RLWE problem. In this work we focus on using polar codes alleviate natural trade-off present schemes; namely, would like wider distribution increase security, but comes at cost of an increased prob...

We provide a generic transformation from weakly selective secure FE to selective secure FE through an approach called hybrid functional key generation. Furthermore, our transformation preserves the compactness of the FE scheme. Additionally, we note that this transformation is much simpler than the prior work [GS16]. We consider the simplicity of the construction in this work as a positive feat...

Ever since the appearance of quantum computers, prime factoring and discrete logarithm-based cryptography have been questioned, giving birth to so-called post-quantum cryptography. The most prominent field in is lattice-based cryptography, protocols that are proved be as difficult break certain hard lattice problems like Learning with Errors (LWE) or Ring (R-LWE). Furthermore, application crypt...

We propose an (n,m)-computationally-private information retrieval (CPIR) protocol with rate 1 − o(1) and highly nontrivial (sublinear and data-dependent) server’s computational complexity. For this, we note that an (n,m)-CPIR protocol is equivalent to a secure function evaluation protocol that evaluates a secret function f on m different inputs. Thus, we first design an efficient multi-level ci...

In CRYPTO 2015, Elias, Lauter, Ozman and Stange described an attack on the non-dual decision version of the ring learning with errors problem (RLWE) for two special families of defining polynomials, whose construction depends on the modulus q that is being used. For particularly chosen error parameters, they managed to solve nondual decision RLWE given 20 samples, with a success rate ranging fr...

We address the practicality challenges of secure program obfuscation by implementing, optimizing, and experimentally assessing an approach to securely obfuscate conjunction programs proposed in [1]. Conjunction programs evaluate functions f (x1, . . . , xL) = ∧ i∈I yi, where yi is either xi or ¬xi and I ⊆ [L], and can be used as classifiers. Our obfuscation approach satisfies distributional Vir...

Since its introduction in 2010 by Lyubashevsky, Peikert and Regev, the Ring Learning With Errors problem (Ring-LWE) has been widely used as a building block for cryptographic primitives, due to its great versatility and its hardness proof consisting of a (quantum) reduction to ideal lattice problems. This reduction assumes a lower bound on the width of the error distribution that is often viola...