Struct RingZq 

pub struct RingZq {
    pub n: usize,
    pub q: u64,
}

Polynomial-ring arithmetic over Z_q[x]/(x^n + 1).

Supports the ring operations needed for Ring-LWE and NTRU-based schemes.

WARNING

Educational implementation. Not optimized or secure.

Fields

n: usize

Ring dimension n (must be a power of 2 for NTT)

q: u64

Modulus q

Implementations

impl RingZq

pub fn new(n: usize, q: u64) -> Self

Create a new ring Z_q[x]/(x^n + 1).

pub fn reduce(&self, poly: &[u64]) -> Vec<u64>

Reduce polynomial coefficients modulo q.

pub fn add(&self, a: &[u64], b: &[u64]) -> Vec<u64>

Add two polynomials in the ring.

pub fn sub(&self, a: &[u64], b: &[u64]) -> Vec<u64>

Subtract two polynomials in the ring.

pub fn mul(&self, a: &[u64], b: &[u64]) -> Vec<u64>

Multiply two polynomials in Z_q[x]/(x^n + 1) using schoolbook multiplication.

O(n^2) — for educational purposes. Real implementations use NTT.

pub fn linf_norm(&self, poly: &[u64]) -> u64

L-infinity norm: max absolute deviation from 0 or q (viewing coefficients as centered in (-q/2, q/2]).