International Association
for Cryptologic Research

In this article, we introduce a new post-quantum cryptosystem, NTWR Prime, which is based on the NTRU Prime and Learning With Rounding (LWR) problems. This scheme is inspired by the NTWE construction proposed by Joel Gartner in 2023. Unlike NTWE, our algorithm employs an irreducible, non-cyclotomic polynomial whose Galois group is isomorphic to the symmetric group. Additionally, the LWR problem is used in place of the LWE problem, offering potential advantages for structural security due to its deterministic nature. We conduct a security analysis demonstrating that solving the NTWR Prime problem requires solving both the underlying NTRU Prime and LWR problems. Consequently, given the absence of definitive post-quantum security proofs for these problems, our construction offers redundancy, which may fulfill the requirements of applications with exceptionally high security standards. Importantly, we show that there exists a set of parameters satisfying the hardness assumptions for both contributing problems.