lintrans

Documentation

Overview

Package lintrans implements homomorphic linear transformations for the BFV/BGV schemes.

Index

• func Encode[T bgv.Integer](ecd schemes.Encoder, diagonals Diagonals[T], allocated LinearTransformation) (err error)
• type Diagonals
  • func (m Diagonals[T]) DiagonalsIndexList() (indexes []int)
  • func (m Diagonals[T]) Evaluate(vector []T, newVec func(size int) []T, add func(a, b, c []T), ...) (res []T)
• type Evaluator
  • func NewEvaluator(eval schemes.Evaluator) (linTransEval *Evaluator)
  • func (eval Evaluator) Evaluate(ctIn *rlwe.Ciphertext, linearTransformation LinearTransformation, ...) (err error)
  • func (eval Evaluator) EvaluateMany(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation, ...) (err error)
  • func (eval Evaluator) EvaluateManyNew(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation) (opOut []*rlwe.Ciphertext, err error)
  • func (eval Evaluator) EvaluateNew(ctIn *rlwe.Ciphertext, linearTransformation LinearTransformation) (opOut *rlwe.Ciphertext, err error)
  • func (eval Evaluator) EvaluateSequential(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation, ...) (err error)
  • func (eval Evaluator) EvaluateSequentialNew(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation) (opOut *rlwe.Ciphertext, err error)
• type LinearTransformation
  • func NewLinearTransformation(params rlwe.ParameterProvider, lt Parameters) LinearTransformation
  • func (lt LinearTransformation) GaloisElements(params rlwe.ParameterProvider) []uint64
• type Parameters
• type Permutation
  • func (p Permutation[T]) GetDiagonals(logSlots int) Diagonals[T]
• type PermutationMapping

Functions

func Encode

func Encode[T bgv.Integer](ecd schemes.Encoder, diagonals Diagonals[T], allocated LinearTransformation) (err error)

Encode is a method used to encode a LinearTransformation and a wrapper of lintrans.Encode.

Types

type Diagonals

type Diagonals[T bgv.Integer] lintrans.Diagonals[T]

Diagonals is a wrapper of lintrans.Diagonals.

func (Diagonals[T]) DiagonalsIndexList

func (m Diagonals[T]) DiagonalsIndexList() (indexes []int)

DiagonalsIndexList returns the list of the non-zero diagonals of the square matrix. A non zero diagonals is a diagonal with a least one non-zero element.

func (Diagonals[T]) Evaluate

func (m Diagonals[T]) Evaluate(vector []T, newVec func(size int) []T, add func(a, b, c []T), muladd func(a, b, c []T)) (res []T)

Evaluate evaluates the linear transformation on the provided vector. add: c = a + b muladd: c = c + a * b

type Evaluator

type Evaluator struct {
	lintrans.Evaluator
}

Evaluator is a struct for evaluating linear transformations on rlwe.Ciphertexts. All fields of this struct are public, enabling custom instantiations.

func NewEvaluator

func NewEvaluator(eval schemes.Evaluator) (linTransEval *Evaluator)

NewEvaluator instantiates a new Evaluator from a schemes.Evaluator. The default bgv.Evaluator is compliant to the schemes.Evaluator interface.

func (Evaluator) Evaluate

func (eval Evaluator) Evaluate(ctIn *rlwe.Ciphertext, linearTransformation LinearTransformation, opOut *rlwe.Ciphertext) (err error)

Evaluate takes as input a ciphertext ctIn, a linear transformation M and evaluates opOut: M(ctIn).

func (Evaluator) EvaluateMany

func (eval Evaluator) EvaluateMany(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation, opOut []*rlwe.Ciphertext) (err error)

EvaluateMany takes as input a ciphertext ctIn, a list of linear transformations [M0, M1, M2, ...] and a list of pre-allocated receiver opOut and evaluates opOut: [M0(ctIn), M1(ctIn), M2(ctIn), ...]

func (Evaluator) EvaluateManyNew

func (eval Evaluator) EvaluateManyNew(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation) (opOut []*rlwe.Ciphertext, err error)

EvaluateManyNew takes as input a ciphertext ctIn and a list of linear transformations [M0, M1, M2, ...] and returns opOut:[M0(ctIn), M1(ctIn), M2(ctInt), ...].

func (Evaluator) EvaluateNew

func (eval Evaluator) EvaluateNew(ctIn *rlwe.Ciphertext, linearTransformation LinearTransformation) (opOut *rlwe.Ciphertext, err error)

EvaluateNew takes as input a ciphertext ctIn and a linear transformation M and evaluate and returns opOut: M(ctIn).

func (Evaluator) EvaluateSequential

func (eval Evaluator) EvaluateSequential(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation, opOut *rlwe.Ciphertext) (err error)

EvaluateSequential takes as input a ciphertext ctIn and a list of linear transformations [M0, M1, M2, ...] and returns opOut:...M2(M1(M0(ctIn))

func (Evaluator) EvaluateSequentialNew

func (eval Evaluator) EvaluateSequentialNew(ctIn *rlwe.Ciphertext, linearTransformations []LinearTransformation) (opOut *rlwe.Ciphertext, err error)

EvaluateSequentialNew takes as input a ciphertext ctIn and a list of linear transformations [M0, M1, M2, ...] and returns opOut:...M2(M1(M0(ctIn))

type LinearTransformation

type LinearTransformation lintrans.LinearTransformation

LinearTransformation is a wrapper of lintrans.Parameters.

func NewLinearTransformation

func NewLinearTransformation(params rlwe.ParameterProvider, lt Parameters) LinearTransformation

NewLinearTransformation instantiates a new LinearTransformation and is a wrapper of lintrans.LinearTransformation.

func (LinearTransformation) GaloisElements

func (lt LinearTransformation) GaloisElements(params rlwe.ParameterProvider) []uint64

GaloisElements returns the list of Galois elements required to evaluate the linear transformation.

type Parameters

type Parameters lintrans.Parameters

Parameters is a wrapper of lintrans.Parameters.

type Permutation

type Permutation[T bgv.Integer] [2][]PermutationMapping[T]

Permutation is a struct that defines generic permutations over 2 x n/2 matrices, treating each row independently.

For example, given the 2x2 matrix [[a, b] [c, d]] that would be mapped to [[1b, 2a] [3c, 4d]] then the Permutation would contain the following map: {{0:{1, 2}, 1:{0: 1}}, {0:{0, 3}: 1:{1, 4}}}

func (Permutation[T]) GetDiagonals

func (p Permutation[T]) GetDiagonals(logSlots int) Diagonals[T]

GetDiagonals returns the non-zero diagonals of the matrix representation of the permutation, which can be used to instantiate Parameters.

type PermutationMapping

type PermutationMapping[T bgv.Integer] struct {
	From    int
	To      int
	Scaling T
}

PermutationMapping is a struct storing a mapping: From -> To and a scaling value.