Trait NttModulus

pub trait NttModulus: Modulus {
    const ZETA: u32;
    const ZETAS: &'static [u32];
    const N_INV: u32;
    const MONT_R: u32;
    const NEG_QINV: u32;
    const PSIS: &'static [u32];
    const INV_PSIS: &'static [u32];
    const POST_INVNTT_MODE: PostInvNtt = PostInvNtt::Standard;
}

Extended trait for NTT-enabled moduli

Required Associated Constants

const ZETA: u32

Primitive root of unity (generator)

const ZETAS: &'static [u32]

Precomputed twiddle factors for forward NTT CRITICAL: For Dilithium, these are stored in MONTGOMERY domain (ζ·R mod q) exactly as in the FIPS-204 reference implementation. Do NOT convert them again - that would give ζ·R² mod q!

const N_INV: u32

N^-1 mod Q for final scaling in inverse NTT This should be in Montgomery form: (N^-1 * R) mod Q

const MONT_R: u32

Montgomery parameter R = 2^32 mod Q

const NEG_QINV: u32

-Q^-1 mod 2^32 for Montgomery reduction (sometimes called NEG_QINV or MONT_QINV)

const PSIS: &'static [u32]

Twist factors ψ_i = ω^(bitrev(i)) in STANDARD domain (length N) These are the N-th roots of the primitive 2N-th root of unity Required for twisted/negacyclic NTT (Dilithium) NOTE: FIPS-204 reference implementation does NOT use these!

const INV_PSIS: &'static [u32]

Inverse twist factors ψ_i^(-1) in STANDARD domain (length N) Required for inverse twisted/negacyclic NTT (Dilithium) NOTE: FIPS-204 reference implementation does NOT use these!

Provided Associated Constants

const POST_INVNTT_MODE: PostInvNtt = PostInvNtt::Standard

How the coefficients should be post-processed after the inverse NTT.

• Standard → Kyber / Saber style
• Montgomery → Dilithium style (invntt_tomont)

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl NttModulus for DilithiumParams

const ZETA: u32 = 1_753u32

const ZETAS: &'static [u32]

const N_INV: u32 = 16_382u32

const MONT_R: u32 = 4_193_792u32

const NEG_QINV: u32 = 4_236_238_847u32

const PSIS: &'static [u32]

const INV_PSIS: &'static [u32]

const POST_INVNTT_MODE: PostInvNtt = PostInvNtt::Standard

impl NttModulus for DilithiumParamsMont

const ZETA: u32 = 1_753u32

const ZETAS: &'static [u32]

const N_INV: u32 = 16_382u32

const MONT_R: u32 = 4_193_792u32

const NEG_QINV: u32 = 4_236_238_847u32

const PSIS: &'static [u32]

const INV_PSIS: &'static [u32]

const POST_INVNTT_MODE: PostInvNtt = PostInvNtt::Montgomery

impl NttModulus for Kyber256Params

const ZETA: u32 = 17u32

const ZETAS: &'static [u32]

const N_INV: u32 = 2_385u32

const MONT_R: u32 = 1_353u32

const NEG_QINV: u32 = 2_488_732_927u32

const PSIS: &'static [u32]

const INV_PSIS: &'static [u32]

const POST_INVNTT_MODE: PostInvNtt = PostInvNtt::Standard