Class Field2n

Defined in File field2n.h

Page Contents

Inheritance Relationships
- Base Types
Class Documentation

Inheritance Relationships

Base Types

public std::vector< std::complex< double > >
public lbcrypto::Serializable (Class Serializable)

Class Documentation

class lbcrypto::Field2n : public std::vector<std::complex<double>>, public lbcrypto::Serializable 

Inheritence diagram for lbcrypto::Field2n:

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Collaboration diagram for lbcrypto::Field2n:

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A class to represent field elements with power-of-2 dimension.

Public Functions

Field2n() noexcept = default: Default Constructor.

inline explicit Field2n(Format f)

inline Field2n(usint size, Format f = Format::EVALUATION, bool initializeElementToZero = false)

Constructor for field element.

Parameters

size – element size
f – format/representation of the element. Initially set to Format::EVALUATION representation.
initializeElementToZero – flag for initializing values to zero. It is set to false by default.

explicit Field2n(const Poly &element)

Constructor from ring element.

Parameters: & – element ring element

explicit Field2n(const NativePoly &element)

Constructor from ring element.

Parameters: & – element ring element

explicit Field2n(const DCRTPoly &element)

Constructor from DCRTPoly ring element.

Parameters: & – element ring element

explicit Field2n(const Matrix<int64_t> &element)

Constructor from a ring element matrix.

Parameters: &element – ring element matrix

inline Format GetFormat() const

Method for getting the format/representation of the element.

Returns: format/representation of the field element

Field2n Inverse() const

Inverse operation for the field elements.

Returns: the inverse field element

Field2n Plus(const Field2n &rhs) const

Addition operation for field elements.

Parameters: &rhs – right hand side element for operation
Returns: result of the operation

Field2n Plus(double rhs) const

Scalar addition operation for field elements.

Parameters: &rhs – right hand side element for operation
Returns: result of the operation

Field2n Minus(const Field2n &rhs) const

Substraction operation for field elements.

Parameters: &rhs – right hand side element for operation
Returns: result of the operation

Field2n Times(const Field2n &rhs) const

Multiplication operation for field elements.

Parameters: &rhs – right hand side element for operation
Returns: result of the operation

Field2n ShiftRight()

Right shift operation for the field element.

Returns: the shifted field element

Field2n AutomorphismTransform(size_t i) const

Performs an automorphism transform operation and returns the result.

Parameters: &i – is the element to perform the automorphism transform with.
Returns: is the result of the automorphism transform.

Field2n Transpose() const

Transpose operation defined in section VI.B4 of https://eprint.iacr.org/2017/844.pdf.

Returns: the transpose of the element

Field2n ExtractOdd() const

Function for extracting odd factors of the field element.

Returns: the field element with odd parts of the initial element

Field2n ExtractEven() const

Function for extracting even factors of the field element.

Returns: the field element with even parts of the initial element

Field2n Permute() const

Permutation operation defined in Algorithm 4 of https://eprint.iacr.org/2017/844.pdf.

Returns: permuted new field element

Field2n InversePermute() const

Inverse operation for permutation operation defined in Algorithm 4 of https://eprint.iacr.org/2017/844.pdf.

Returns: non permuted version of the element

Field2n ScalarMult(double d)

Operation for scalar multiplication.

Parameters: d – scalar for multiplication
Returns: the field element with the scalar multiplication

void SwitchFormat(): Method for switching format of the field elements.

inline void SetFormat(Format f)

Sets the evaluation or coefficient representation of the field elements.

Parameters: &format – the enum value corresponding to coefficient or evaluation representation

inline size_t Size() const

Method for getting the size of the element.

Returns: the size of the element

inline std::complex<double> &operator[](size_t idx)

Indexing operator for field elements.

Parameters: idx – index of the element
Returns: element at the index

inline const std::complex<double> &operator[](size_t idx) const

Indexing operator for field elements.

Parameters: idx – index of the element
Returns: element at the index

inline Field2n &operator+=(const Field2n &element)

In-place addition operation for field elements.

Parameters: &element – right hand side element for operation
Returns: result of the operation

inline Field2n &operator-=(const Field2n &element)

In-place subtraction operation for field elements.

Parameters: &element – right hand side element for operation
Returns: result of the operation

inline Field2n operator-() const

Unary minus on a field element.

Returns: negation of the field element.

template<class Archive> inline void save(Archive &ar, std::uint32_t const version) const

template<class Archive> inline void load(Archive &ar, std::uint32_t const version)

inline virtual std::string SerializedObjectName() const override

Public Static Functions

static inline uint32_t SerializedVersion()

Friends

inline friend Field2n operator-(const Field2n &a, const Field2n &b)

Substraction operator for field elements.

Parameters

&a – left hand side field element
&b – right hand side field element

Returns

result of the substraction operation

inline friend Field2n operator+(const Field2n &a, const Field2n &b)

Addition operator for field elements.

Parameters

&a – left hand side field element
&b – right hand side field element

Returns

result of the addition operation

inline friend Field2n operator+(const Field2n &a, double scalar)

Scalar addition operator for field elements.

Parameters

&a – left hand side field element
&b – the scalar to be added

Returns

result of the addition operation

inline friend Field2n operator*(const Field2n &a, const Field2n &b)

Multiplication operator for field elements.

Parameters

&a – left hand side field element
&b – right hand side field element

Returns

result of the multiplication operation