cx_mldsa_poly.c File Reference

ML-DSA polynomial arithmetic (FIPS 204). More...

#include "cx_mldsa_poly.h"

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Functions
int32_t	MLDSA_POLY_montgomery_reduce (int64_t a)
	Montgomery reduction: given a 64-bit integer, compute a*q^{-1} mod 2^32.
int32_t	MLDSA_POLY_reduce32 (int32_t a)
	Reduce coefficient to representative in about (-6283009, 6283009).
int32_t	MLDSA_POLY_caddq (int32_t a)
	Adds q if input is negative.
void	MLDSA_POLY_reduce (mldsa_poly *a)
	Applies reduce32 to all coefficients of a polynomial.
void	MLDSA_POLY_caddq_all (mldsa_poly *a)
	Applies caddq to all coefficients of a polynomial.
void	MLDSA_POLY_add (mldsa_poly *a, const mldsa_poly *b)
	Adds polynomial b to polynomial a in place.
void	MLDSA_POLY_sub (mldsa_poly *a, const mldsa_poly *b)
	Subtracts polynomial b from polynomial a in place.
void	MLDSA_POLY_shiftl (mldsa_poly *a)
	Shifts all coefficients left by D bits.
void	MLDSA_POLY_ntt (mldsa_poly *a)
	Forward NTT in place.
void	MLDSA_POLY_invntt_tomont (mldsa_poly *a)
	Inverse NTT and multiply by Montgomery factor.
void	MLDSA_POLY_pointwise_montgomery (mldsa_poly *c, const mldsa_poly *a, const mldsa_poly *b, int first)
	Pointwise multiplication (Montgomery) with accumulation.
int	MLDSA_POLY_chknorm (const mldsa_poly *a, int32_t B)
	Checks infinity norm of polynomial against bound B.

Variables
static const int32_t	mldsa_zetas [MLDSA_N]

Detailed Description

ML-DSA polynomial arithmetic (FIPS 204).

Implements NTT, inverse NTT, Montgomery reduction, pointwise multiplication, and related polynomial operations for the ML-DSA ring Z_q[X]/(X^256+1).

Definition in file cx_mldsa_poly.c.

Function Documentation

MLDSA_POLY_add()

void MLDSA_POLY_add	(	mldsa_poly *	a,
		const mldsa_poly *	b
	)

Adds polynomial b to polynomial a in place.

Parameters

[in,out]	a	Accumulator polynomial.
[in]	b	Polynomial to add.

Definition at line 104 of file cx_mldsa_poly.c.

MLDSA_POLY_caddq()

int32_t MLDSA_POLY_caddq

(

int32_t

a

)

Adds q if input is negative.

Parameters

[in]

a

Input coefficient in (-q, q).

Returns

Coefficient in [0, q).

Definition at line 84 of file cx_mldsa_poly.c.

MLDSA_POLY_caddq_all()

void MLDSA_POLY_caddq_all

(

mldsa_poly *

a

)

Applies caddq to all coefficients of a polynomial.

Parameters

[in,out]

a

Polynomial to make positive.

Definition at line 97 of file cx_mldsa_poly.c.

MLDSA_POLY_chknorm()

int MLDSA_POLY_chknorm	(	const mldsa_poly *	a,
		int32_t	B
	)

Checks infinity norm of polynomial against bound B.

Parameters

[in]	a	Polynomial.
[in]	B	Norm bound.

Returns

0 if all coefficients within bound, 1 otherwise.

Definition at line 179 of file cx_mldsa_poly.c.

MLDSA_POLY_invntt_tomont()

void MLDSA_POLY_invntt_tomont

(

mldsa_poly *

a

)

Inverse NTT and multiply by Montgomery factor.

Parameters

[in,out]

a

Polynomial to inverse-transform.

Definition at line 141 of file cx_mldsa_poly.c.

MLDSA_POLY_montgomery_reduce()

int32_t MLDSA_POLY_montgomery_reduce

(

int64_t

a

)

Montgomery reduction: given a 64-bit integer, compute a*q^{-1} mod 2^32.

Parameters

[in]

a

64-bit input.

Returns

32-bit reduced value in (-q, q).

Definition at line 68 of file cx_mldsa_poly.c.

MLDSA_POLY_ntt()

void MLDSA_POLY_ntt

(

mldsa_poly *

a

)

Forward NTT in place.

Parameters

[in,out]

a

Polynomial to transform.

Definition at line 125 of file cx_mldsa_poly.c.

MLDSA_POLY_pointwise_montgomery()

void MLDSA_POLY_pointwise_montgomery	(	mldsa_poly *	c,
		const mldsa_poly *	a,
		const mldsa_poly *	b,
		int	first
	)

Pointwise multiplication (Montgomery) with accumulation.

Parameters

[in,out]	c	Accumulator polynomial.
[in]	a	First input polynomial.
[in]	b	Second input polynomial.
[in]	first	If non-zero, overwrite c; otherwise accumulate.

Definition at line 163 of file cx_mldsa_poly.c.

MLDSA_POLY_reduce()

void MLDSA_POLY_reduce

(

mldsa_poly *

a

)

Applies reduce32 to all coefficients of a polynomial.

Parameters

[in,out]

a

Polynomial to reduce.

Definition at line 90 of file cx_mldsa_poly.c.

MLDSA_POLY_reduce32()

int32_t MLDSA_POLY_reduce32

(

int32_t

a

)

Reduce coefficient to representative in about (-6283009, 6283009).

Parameters

[in]

a

Input coefficient.

Returns

Reduced coefficient.

Definition at line 76 of file cx_mldsa_poly.c.

MLDSA_POLY_shiftl()

void MLDSA_POLY_shiftl

(

mldsa_poly *

a

)

Shifts all coefficients left by D bits.

Parameters

[in,out]

a

Polynomial to shift.

Definition at line 118 of file cx_mldsa_poly.c.

MLDSA_POLY_sub()

void MLDSA_POLY_sub	(	mldsa_poly *	a,
		const mldsa_poly *	b
	)

Subtracts polynomial b from polynomial a in place.

Parameters

[in,out]	a	Accumulator polynomial.
[in]	b	Polynomial to subtract.

Definition at line 111 of file cx_mldsa_poly.c.

Variable Documentation

mldsa_zetas

const int32_t mldsa_zetas[MLDSA_N]

static

Definition at line 27 of file cx_mldsa_poly.c.