Search results for "post-quantum cryptography"
showing 3 items of 3 documents
Non-commutative Ring Learning with Errors from Cyclic Algebras
2022
AbstractThe Learning with Errors (LWE) problem is the fundamental backbone of modern lattice-based cryptography, allowing one to establish cryptography on the hardness of well-studied computational problems. However, schemes based on LWE are often impractical, so Ring LWE was introduced as a form of ‘structured’ LWE, trading off a hard to quantify loss of security for an increase in efficiency by working over a well-chosen ring. Another popular variant, Module LWE, generalizes this exchange by implementing a module structure over a ring. In this work, we introduce a novel variant of LWE over cyclic algebras (CLWE) to replicate the addition of the ring structure taking LWE to Ring LWE by add…
Quantum Security Proofs Using Semi-classical Oracles
2019
We present an improved version of the one-way to hiding (O2H) Theorem by Unruh, J ACM 2015. Our new O2H Theorem gives higher flexibility (arbitrary joint distributions of oracles and inputs, multiple reprogrammed points) as well as tighter bounds (removing square-root factors, taking parallelism into account). The improved O2H Theorem makes use of a new variant of quantum oracles, semi-classical oracles, where queries are partially measured. The new O2H Theorem allows us to get better security bounds in several public-key encryption schemes.
A general framework for group authentication and key exchange protocols
2014
Published version of a chapter in the book: Foundations and Practice of Security. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-319-05302-8_3 In this paper, we propose a novel framework for group authentication and key exchange protocols. There are three main advantages of our framework. First, it is a general one, where different cryptographic primitives can be used for different applications. Second, it works in a one-to-multiple mode, where a party can authenticate several parties mutually. Last, it can provide several security features, such as protection against passive adversaries and impersonate attacks, implicit key authentication, forward and backward securi…