lbcrypto::LatticeGaussSampUtility< Element > Class Template Reference

Utility class containing operations needed for lattice sampling; Sources: https://eprint.iacr.org/2017/844.pdf and https://eprint.iacr.org/2017/308.pdf This construction is based on the hardness of Ring-LWE problem. More...

#include <dgsampling.h>

Static Public Member Functions
static void	GaussSampGq (const Element &u, double stddev, size_t k, const typename Element::Integer &q, int64_t base, typename Element::DggType &dgg, Matrix< int64_t > *z)
static void	GaussSampGqArbBase (const Element &u, double stddev, size_t k, const typename Element::Integer &q, int64_t base, typename Element::DggType &dgg, Matrix< int64_t > *z)
static void	ZSampleSigma2x2 (const Field2n &a, const Field2n &b, const Field2n &d, const Matrix< Field2n > &c, const typename Element::DggType &dgg, shared_ptr< Matrix< int64_t >> p)
static void	SampleMat (const Matrix< Field2n > &A, const Matrix< Field2n > &B, const Matrix< Field2n > &D, const Matrix< Field2n > &C, const typename Element::DggType &dgg, shared_ptr< Matrix< int64_t >> p)
static shared_ptr< Matrix< int64_t > >	ZSampleF (const Field2n &f, const Field2n &c, const typename Element::DggType &dgg, size_t n)

Detailed Description

template<class Element>
class lbcrypto::LatticeGaussSampUtility< Element >

Utility class containing operations needed for lattice sampling; Sources: https://eprint.iacr.org/2017/844.pdf and https://eprint.iacr.org/2017/308.pdf This construction is based on the hardness of Ring-LWE problem.

Member Function Documentation

GaussSampGq()

template<class Element >

void lbcrypto::LatticeGaussSampUtility< Element >::GaussSampGq ( const Element &  u, double  stddev, size_t  k, const typename Element::Integer &  q, int64_t  base, typename Element::DggType &  dgg, Matrix< int64_t > *  z  )

static

Gaussian sampling from lattice for gagdet matrix G, syndrome u, and arbitrary modulus q Discrete sampling variant As described in Figure 2 of https://eprint.iacr.org/2017/308.pdf

Parameters

u	syndrome (a polynomial)
sttdev	standard deviation
k	number of components in the gadget vector
q	integer modulus
base	base of gadget matrix
dgg	discrete Gaussian generator
*z	a set of k sampled polynomials corresponding to the gadget matrix G; represented as Z^(k x n)

GaussSampGqArbBase()

template<class Element >

void lbcrypto::LatticeGaussSampUtility< Element >::GaussSampGqArbBase ( const Element &  u, double  stddev, size_t  k, const typename Element::Integer &  q, int64_t  base, typename Element::DggType &  dgg, Matrix< int64_t > *  z  )

static

Gaussian sampling from lattice for gagdet matrix G, syndrome u, and arbitrary modulus q Continuous sampling variant As described in Algorithm 3 of https://eprint.iacr.org/2017/844.pdf

Parameters

u	syndrome (a polynomial)
sttdev	standard deviation
k	number of components in the gadget vector
q	integer modulus
base	base of gadget matrix
dgg	discrete Gaussian generator
*z	a set of k sampled polynomials corresponding to the gadget matrix G; represented as Z^(k x n)

SampleMat()

template<class Element >

void lbcrypto::LatticeGaussSampUtility< Element >::SampleMat ( const Matrix< Field2n > &  A, const Matrix< Field2n > &  B, const Matrix< Field2n > &  D, const Matrix< Field2n > &  C, const typename Element::DggType &  dgg, shared_ptr< Matrix< int64_t >>  p  )

static

Subroutine used by SamplePertSquareMat as described in "Implementing Token-Based Obfuscation under (Ring) LWE"

Parameters

A	a matrix of field elements in DFT format
B	a matrix of field elements in DFT format
D	a matrix of field elements in DFT format
C	a matrix of field elements in Coefficient format
dgg	discrete Gaussian generator
*p	non-spherical perturbation matrix; output of the function

ZSampleF()

template<class Element >

shared_ptr< Matrix< int64_t > > lbcrypto::LatticeGaussSampUtility< Element >::ZSampleF ( const Field2n &  f, const Field2n &  c, const typename Element::DggType &  dgg, size_t  n  )

static

Subroutine used by ZSampleSigma2x2 as described Algorithm 4 in https://eprint.iacr.org/2017/844.pdf

Parameters

f	field element in Coefficient format
c	field element in Coefficient format
dgg	discrete Gaussian generator
n	ring dimension used for rejection sampling

ZSampleSigma2x2()

template<class Element >

void lbcrypto::LatticeGaussSampUtility< Element >::ZSampleSigma2x2 ( const Field2n &  a, const Field2n &  b, const Field2n &  d, const Matrix< Field2n > &  c, const typename Element::DggType &  dgg, shared_ptr< Matrix< int64_t >>  p  )

static

Subroutine used by ZSampleSigmaP as described Algorithm 4 in https://eprint.iacr.org/2017/844.pdf

Parameters

a	field element in DFT format
b	field element in DFT format
d	field element in DFT format
c	a vector of field elements in Coefficient format
dgg	discrete Gaussian generator
p	non-spherical perturbation vector; output of the function

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

• src/core/include/lattice/dgsampling.h
• src/core/lib/lattice/dgsampling.cpp