hetest::utils::NTT Class Reference

Performs negacyclic forward and inverse number-theoretic transform (NTT), commonly used in RLWE cryptography. More...

#include <ntt.hpp>

Classes
struct	AllocatorAdapter
class	NTTImpl

Public Member Functions
	NTT ()
	Initializes an empty NTT object. More...
	~NTT ()
	Destructs the NTT object. More...
	NTT (uint64_t degree, uint64_t q, std::shared_ptr< AllocatorBase > alloc_ptr={})
	Performs pre-computation necessary for forward and inverse transforms. More...
template<class Allocator , class... AllocatorArgs>
	NTT (uint64_t degree, uint64_t q, Allocator &&a, AllocatorArgs &&...args)
	NTT (uint64_t degree, uint64_t q, uint64_t root_of_unity, std::shared_ptr< AllocatorBase > alloc_ptr={})
	Initializes an NTT object with degree degree and modulus q. More...
template<class Allocator , class... AllocatorArgs>
	NTT (uint64_t degree, uint64_t q, uint64_t root_of_unity, Allocator &&a, AllocatorArgs &&...args)
void	ComputeForward (uint64_t *result, const uint64_t *operand, uint64_t input_mod_factor, uint64_t output_mod_factor)
	Compute forward NTT. Results are bit-reversed. More...
void	ComputeInverse (uint64_t *result, const uint64_t *operand, uint64_t input_mod_factor, uint64_t output_mod_factor)

Public Attributes
std::shared_ptr< NTTImpl >	m_impl
	Class implementing the NTT. More...

Detailed Description

Performs negacyclic forward and inverse number-theoretic transform (NTT), commonly used in RLWE cryptography.

The number-theoretic transform (NTT) specializes the discrete Fourier transform (DFT) to the finite field \( \mathbb{Z}_q[X] / (X^N + 1) \).

Constructor & Destructor Documentation

hetest::utils::NTT::NTT ( )

default

Initializes an empty NTT object.

hetest::utils::NTT::~NTT ( )

default

Destructs the NTT object.

hetest::utils::NTT::NTT	(	uint64_t	degree,
		uint64_t	q,
		std::shared_ptr< AllocatorBase >	alloc_ptr = {}
	)

Performs pre-computation necessary for forward and inverse transforms.

Initializes an NTT object with degree degree and modulus q.

Parameters

[in]	degree	also known as N. Size of the NTT transform. Must be a power of 2
[in]	q	Prime modulus. Must satisfy \( q == 1 \mod 2N \)
[in]	alloc_ptr	Custom memory allocator used for intermediate calculations

template<class Allocator , class... AllocatorArgs>

hetest::utils::NTT::NTT ( uint64_t  degree, uint64_t  q, Allocator &&  a, AllocatorArgs &&...  args  )

inline

hetest::utils::NTT::NTT	(	uint64_t	degree,
		uint64_t	q,
		uint64_t	root_of_unity,
		std::shared_ptr< AllocatorBase >	alloc_ptr = {}
	)

Initializes an NTT object with degree degree and modulus q.

Parameters

[in]	degree	also known as N. Size of the NTT transform. Must be a power of 2
[in]	q	Prime modulus. Must satisfy \( q == 1 \mod 2N \)
[in]	root_of_unity	2N'th root of unity in \( \mathbb{Z_q} \).
[in]	alloc_ptr	Custom memory allocator used for intermediate calculations

Performs pre-computation necessary for forward and inverse transforms

template<class Allocator , class... AllocatorArgs>

hetest::utils::NTT::NTT ( uint64_t  degree, uint64_t  q, uint64_t  root_of_unity, Allocator &&  a, AllocatorArgs &&...  args  )

inline

Member Function Documentation

void hetest::utils::NTT::ComputeForward	(	uint64_t *	result,
		const uint64_t *	operand,
		uint64_t	input_mod_factor,
		uint64_t	output_mod_factor
	)

Compute forward NTT. Results are bit-reversed.

Parameters

[out]	result	Stores the result
[in]	operand	Data on which to compute the NTT
[in]	input_mod_factor	Assume input operand are in [0, input_mod_factor * q). Must be 1, 2 or 4.
[in]	output_mod_factor	Returns output operand in [0, output_mod_factor * q). Must be 1 or 4.

void hetest::utils::NTT::ComputeInverse	(	uint64_t *	result,
		const uint64_t *	operand,
		uint64_t	input_mod_factor,
		uint64_t	output_mod_factor
	)

Compute inverse NTT. Results are bit-reversed.

Parameters

[out]	result	Stores the result
[in]	operand	Data on which to compute the NTT
[in]	input_mod_factor	Assume input operand are in [0, input_mod_factor * q). Must be 1 or 2.
[in]	output_mod_factor	Returns output operand in [0, output_mod_factor * q). Must be 1 or 2.

Member Data Documentation

std::shared_ptr<NTTImpl> hetest::utils::NTT::m_impl

Class implementing the NTT.

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The documentation for this class was generated from the following files:

• ntt.hpp
• ntt.cpp